HomeMy WebLinkAboutAPA1499USE OF NORTH SLOPE GAS FOR
H EAT AND ELECTRICITY IN THE RAILBEL T
DRAFT FINAL
REPORT
FEASIBILITY . LEVEL
ASSESSMENT
' .'
.. . .
• j
EBASCO
EB ASCO SERVICES
INCORPORATED
JANUARY 1983
1--~ARZA-EEASCO
Susitna Joint Venture
Document Number
Ple ase Re turn To
n n ~l'!.''lf:~~T "'I f-Tit'! 1 ~ U w \: Jr ;, .. wa ."'.. ~ _. ~ .. "' .... b-.
.______ __ ALA KA 0 ER AUT OR T
USE OF NORTH SLOPE GAS FOR
HEAT AND ELECTRICITY IN THE RAILBELT
DRAFT FINAL REPORT
FEASIBILTY LEVEL
ASSESSf~ENT
PRELIMINARY
SUBJECT TO CHANGE
BASED ON REVIE\'1
EBASCO SERVICES INCORPORATED
with
FRANK MODLIN & ASSOCIATES
and
ALASKA ECONOMICS INCORPORATED
FEBRUARY 1983
TABLE OF COtJTENTS
1.0 INTRODUCTION • . •••
1.1 ~URPOSE.....
1.2 STUDY APPROACH
1.3 SCOPE .•..•
1.4 RESULTS.• • .
. .. .. .......
Page
1-1
1-1
1-1
1-2
1-6
2.0 NORTH SLOPE POWER GENERATION -MEDIUM LOAD FORECAST.2-1
2.1 POWER PLANT •••••••••••••
2.3 COST ESTIMATES •••••••••••••
2.4 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS
2-1
2-1
2-1
2-2
2-7
2-10
2-12
2-14
2-15
2-16
2-16
2-18
2-19
2-19
2-20
2-20
2-22
2-22
2-24
2-24
2-25
2-25
2-28
2-28
2-32
2-32
2-34
2-34
2-38
2-41
2-43
2-44
2-49
General . . . . . . . . . . . .
Combustion Turbine Equipment
Fuel Supply • • • • • • • • • •
Swi tctlya rd.. . .... . . . . . . . . . . .
Power Plant Support System Descriptions ••
Construction and Site Support Services
Operation and Maintenance ••;•••
Site Opportunities and Constraints • . • •
Construction Costs ••••••.•
Operating and Maintenance Costs.
Fuel Costs.• • • • • • • • • •
Total System Costs.• • • ••••.
Air Resource Effects •••••••
Water Resource Effects . • • • • •
Aquatic Ecosystem Effects ••••.
Terrestrial Ecosystem Effects •~•
Socioeconomic and Land Use Effects
2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
2.1.6
2.1.7
2.1.8
2.2.1 Overview ••••
2.2.2 Voltage Selection
2.2.3 Towers •••••
2.2.4 Conductors ••••
2.2.5 Insulators •••
2.2.6 Switching Stations
2.2.7 Fairbanks Substation ••••
2.2.8 Construction •••••.
2.2.9 Operation and Maintenance.• ••••
2.2.10 Communications • • • • • • •••••
2.2.11 Siting Opportunities and Constraints
2.2.12 Fairbanks to Anchorage Line.
2.4.1
2.4.2
2.4.3
2.4.4
2.4.5
2.3.1
2.3.2
2.3.3
2.3.4
2.2 TRANSMISSION SYSTEM ••
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2999A
~TABLE OF CONTENTS (Continued)
Page
4.6 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS 4-66
4.6.1 Air Resource Effects ·· ·· ·····4-74
~4.6.2 Water Resource Effects 4-77· ·
·· ·
· ·4.6.3 Aquatic Ecosystem Effects •· · · ···4-79
4.6.4 Terrestri a1 Ecosystem Effects ····4-81,.,...4.6.5 Socioeconomic and Land Use Effects 4-82
5.0 FAIRBANKS POWER GENERATION -LOW LOAD FORECAST · ·
· ·
5-1
...-5.1 NORTH SLOPE TO FAIRBANKS NATURAL GAS PIPELINE 5-1
5.1•1 Gas Conditioning Plant ·· · · ·
·5-2
5.1.2 Pi pel ine ······5-3
5.2 POWER PLANT .· · · · ·
··· ·
5-3
~5.3 TRANSMISSION SYSTEM ·· ·
···5-6
5.3.1 Fairbanks to Anchorage · · ·
·5-6
~~5.4 FAIRBANKS GAS DISTRIBUTION SYSTEM 5-6· ·· ·
·
5.4.1 Fairbanks Residential/Commercial Gas-Demand Forecasts · · ···· ·
·5-6·5.4.2 Fairbanks Gas Distribution System 5-6
-5.5 COST ESTIMATES.· · · · · · · ·· ·
· ·
5-8
5.5.1 Capital Costs •· ·
·· · · · · ·
5-8
5.5.2 Operating and Maintenance Costs •5-10
5.5.3 Fuel Costs ·· ·· ·
· ·····5-13
5.5.4 Total System Costs ·· ··· ·
·5-13
-5.6 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS •·5-23
6.0 KENAI AREA POWER GENERATION -MEDIUM LOAD FORECAST 6-1
~}!i'iIIfi+6.1 POWER PLANT 6-2.· ·
········· ····
6.1.1 General · · · ·
·· · · · ·······6-2
f'l'4lft 6.1.2 Combustion Turbine Equipment.6-3
6.1.3 Steam Pl ant •··· ·· ·· ·
·6-3
6.1.4 Fuel Supply •· · · · · ··· ·
6-5
'"""6.1.5 El ectri cal Equipment ·· ····· ·
6-5
6.1.6 Other Systems •· · ·
6-5
..-
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2999A
TABLE OF CONTENTS (Continued)
6.3 COST ESTIMATES • • • • • • • . • • •
6.3.1 Construction Costs ••••••
6.3.2 Operation and Maintenance Costs ••
6.3.3 Fuel Costs •••••••••••
6.3.4 Total Systems Costs •••••••
6.2 TRANSMISSION SYSTEMS
-
.....
-
6.2.1
6.2.2
6.2.3
6.2.4
. .. ... ... .
Kenai to Anchorage Line
Anchorage Substation •••
Anchorage to Fairbanks Line
Fairbanks Substation
Page
6-7
6-7
6-9
6-9
6-11
6-11
6-11
6-16
6-18
6-18
6.4 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS 6-23
9.0 REFERENCES • • . • • • • •
7.4 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS
8.0 COMPARISON OF SCENARIOS ••
6.4.1 Air Resource Effects ••••••
6.4.2 Water Resource Effects .'••••••
6.4.3 Aquatic Ecosystem Effects ••••••
6.4.4 Terrestri a1 Ecosystem Effects • • • •
6.4.5 Socioeconomic and Land Use Effects ••••
7.0 KENAI AREA POWER GENERATION -LOW LOAD FORECAST.
7.1 POWER PLANT • • • • • • • •• • • •
7.2 TRANSMISSION SYSTEM . • • • • . • • • • •
7.3 COST ESTIMATES • • • • • • • • • • • • • • • • • •
6-23
6-24
6-25
6-26
6-28
7-1
7-1
7-3
7-5
7-5
7-5
7-8
7-8
7-8
8-1
9-1
Construction Costs •••.••••
Operation and Maintenance Costs
Fuel Costs ••••••••••
Total Systems Costs • • • • . • •
7.3.1
7.3.2
7.3.3
7.3.4
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,,"""
.-
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2999A
-LIST OF TABLES (Continued)
-Tabl e Number Title Page
3-4 TOTAL ANNUAL CAPITAL EXPENDITURES
NORTH SLOPE POWER GENERATION -LOW LOAD
"'""FORECAST 3-9
3-5 TOTAL ANNUAL NON-FUEL OPERATING AND
MAINTENANCE COSTS
NORTH SLOPE POWER GENERATION -LOW LOAD
FORECAST 3-10
....3-6 TOTAL ANNUAL FUEL COST REPORT
NORTH SLOPE POWER GENERATION -LOW LOAD
FORECAST 3-11
~
3-7 TOTAL ANNUAL COSTS
NORTH SLOPE POWER GENERATION -LOW LOAD
~FORECAST 3-12
3-7 ENVIRONMENT RELATED POWER PLANT CHARACTERISTICS
NORTH SLOPE POWER GENERATION -LOW LOAD FORECAST 3-13....
4-1 GAS DELIVERY AND QUALITY SPECIFICATIONS 4-4
~4-2 PIPE DETAILS 4-14
4-3 CIVIL DESIGN DETAILS 4-15
f""'"4-4 BUILDING DETAILS 4-16
4-5 COMPRESSOR AND GAS SCRUBBER DETAILS 4-17
4-6 REFRIGERATION SYSTEM AND GAS HEATER DETAILS 4-18
-4-7 COMPRESSOR STATION
ELECTRICAL SYSTEM AND CONTROL SYSTEM DETAILS 4-19
.-4-8 MISCELLANEOUS COMPRESSOR STATION SYSTEMS'DETAILS 4-20
4-9 METERS AND METERING STATION ELECTRICAL AND CONTROL
SYSTEMS DETAILS 4-21
,-
4-10 MISCELLANEOUS METERING STATION SYSTEMS'DETAILS 4-22
-4-11 NEW CAPACITY ADDITIONS AND FUEL REQUIREMENTS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-26
4-12 HEAT RECOVERY STEAM GENERATOR DESIGN PARAMETERS 4-31
vii
2999A
....
f -
-
,..,.
LIST OF TABLES (Continued)
Tabl e Number Title Page
4-13 STEAM TURBINE GENERATOR UNIT DESIGN PARAMETERS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-34
4-14 ORDER OF MAGNITUDE INVESTMENT COSTS
NORTH SLOPE TO FAIRBANKS NATURAL GAS PIPELINE 4-56.-
4-15 ORDER OF MAGNITUDE INVESTMENT COST ESTIMATES
77 MW SIMPLE CYCLE COMBUSTION TURBINE 4-57
.-
4-16 ORDER OF MAGNITUDE INVESTMENT COSTS
220 MW COMBINED CYCLE PLANT.4-58
~4-17 ORDER OF MAGNITUDE INVESTMENT COSTS
FAIRBANKS TO ANCHORAGE TRANSMISSION SYSTEM 4-60
-~4-18 0A VALUES
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-65
.-4-19 TOTAL ANNUAL CAPITAL EXPENDITURES
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-67
4-20 TOTAL ANNUAL NON-FUEL OPERATING AND MAINTENANCE
COSTS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-68
4-21 TOTAL ANNUAL COSTS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-69
4-22 APPORTIONMENT VALUES FOR THE GAS DISTRIBUTION
SYSTEM
FAIRBANKS POWER GENERATION -MEDIUM LOAD SCENARIO 4-70
~4-23 TOTAL ANNUAL CAPITAL EXPENDITURES FOR THE GAS
DISTRIBUTION SYSTEM
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-71
4-24 TOTAL ANNUAL NON-FUEL OPERATING AND MAINTENANCE
COSTS FOR THE GAS DISTRIBUTION SYSTEM
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-72
4-25 ANNUAL SYSTEMS COST SUMMARY,GAS DISTRIBUTION
SYSTEM-FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST 4-73
4-26 ENVIRONMENT RELATED POWER PLANT CHARACTERISTICS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST
COMBINED CYCLE POWER PLANT 4-76
viii
2999A
_'_"'.._~m --------1--·-----------------
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2999A
2999A
x
.-.2999A
xi
LIST OF FIGURES
~Figure Number Title Page
1-1 NORTH SLOPE SCENARIO 1-3
F'"1-2 FAIRBANKS SCENARIO 1-5
1-3 KENAI SCENARIO 1-7-,
2-1 SIMPLE CYCLE GAS TURBINE GENERAL ARRANGEMENT 2-4
..-2-2 SIMPLE CYCLE GAS TURBINE SITE PLAN -NORTH SLOPE 2-5
2-3 NORTH SLOPE POWER GENERATION -MEDIUM LOAD
~FORECAST -SUBSTATION ONE LINE SCHEMATIC 2-9
2-4 NORTH SLOPE POWER GENERATION -MEDIUM LOAD
FORECAST -INITIAL STAGE OF SUBSTATION
DEVELOPMENT 2-11
2-5 NORTH SLOPE POWER GENERATION -MEDIUM LOAD
.....FORECAST -GALBRAITH LAKE AND PROSPECT C,GMP
SWITCHING STATION SCHEMATIC 2-21
2-6 NORTH SLOPE POWER GENERATION -MEDIUM LOAD.....FORECAST -FAIRBANKS SUBSTATION SCHEMATIC 2-23
2-7 NORTH SLOPE POWER GENERATION -MEDIUM LOAD
FORECAST -FAIRBANKS -ANCHORAGE INTERMEDIATE
SWI TCHING STATION SCHEMA TIC 2-27
-2-8 NORTH SLOPE POWER GENERATION -MEDIUM LOAD
FORECAST -ANCHORAGE SUBSTATION SCHEMATIC 2-28
3-1 NORTH SLOPE POWER GENERATION -LOW LOAD
~FORECAST -SUBSTATION ONE LINE SCHEMATIC 3-4
4-1 GAS CmmITIONING FACILITY 4-6-4-2 HYDRAULIC SUMt4ARY -PEAK DAILY FLOW 4-10
4-3 COMPRESSOR STATION 4-12~
4-4 METERING STATION 4-13
4-5 GENERAL ARRANGEMENT -PLAN VIEW 4-27
4-6 GENERAL ARRANGEMENT -ELEVATIONS 4-28
,~
xii
2999A,-
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2999A
xiii
1.0 SUMt1ARY
,~
1•1 PURPOSE
-
~.
-
--
-
The purpose of this study is to examine the technical and environmental
feasibility of several alternatives for the utilization of North Slope
natural gas to generate electricity for use in the Railbelt Region,and
to develop conceptual level,order of magnitude cost estimates for each
alternative.The alternatives are grouped into three scenarios based
on selected generating locations,and the study is based on the medium
and low growth forecasts of Railbelt electrical needs provided by
previous studies.One scenario also provides for the development of a
residential and commercial natural gas distribution system in Fairbanks.
Previous reports developed for this feasibility assessment have
detailed the existing data and assumptions to be used in developing the
scenarios,the technical and economic bases for establishing power
generating technologies,and the factors to be considered in facility
siting and corridor selection.Potential environmental effects are
detailed in this report.The previous reports are appended to this
report for completeness.
1.2 STUDY APPROACH
An initial survey of the electrical demand growth forecasts and the
availability and characteristics of North Slope gas provided a basis
for establishing candidate power generating technologies.Meetings and
discussions with knowledgeable officials and industry representatives
were held to focus the study on factors unique to each region,and
factors unique to North Slope natural gas.Candidate generating sites
and routing corridors (both electrical and natural gas)were
evaluated.Forecasts of potential natural gas demand in Fairbanks and
details for a gas distribution system were prepared.
26478
1-1
-----------_~eo=====."....,......_----------------------
~-
~,
-
"""
Much of the above was completed prior to performing cost estimating
tasks.While this studY uses assumptions consistent with previous
studies of other electrical generating scenarios for the Rai1be1t.cost
estimating tasks have not included fuel cost derivation nor the
development of cost of power values.Comparisons with alternative
electric generating scenarios are therefore outside the scope of this
study.Such comparisons can be considered as a logical extension of
these studies which may be performed by the Alaska Power Authority.
1.3 SCOPE
The scope of the study was defined by the Alaska Power Authority to
consist of three distinct scenarios.Each scenario was evaluated for
its feasibility to meet the medium and low load forecasts of recent
previous studies which examined the electrical demand requirements of
the Rai1be1t Region.The first scenario is characterized by the
generation of electricity on the North Slope using simple cycle
combustion turbines fired by untreated natural gas.A major.new
transmission line system would be required from the North Slope to
Fairbanks.with substantial improvements to the transmission system
connecting Fairbanks and Anchorage.Figure 1-1 is a depiction of the
North Slope scenario showing the major differences between the medium
and low load cases.The medium load forecast requires 15 units with a
total capacity of almost 1400 megawatts (MW).two 500 kilovolt (kV)
circuits from the North Slope to Fairbanks.and three 345 kV circuits
from Fairbanks to Anchorage.The low load forecast can be met with 8
units (700 MW).two 500 IcV circuits from the North Slope to Fairbanks.
and two 345 kV circuits from Fairbanks to Anchorage.The present worth
of costs of the medium load forecast is $3.8 billion versus $2.7
billion for the low load forecast.Both costs are in 1982 dollars and
do not include fuel costs.
The second scenari 0 consists of two di sti nct parts:a generati ng
facility in the Fairbanks area and a gas distri~ution system in
Fairbanks.Transmission of the gas to Fairbanks from the North Slope
would require construction of a high pressure gas pipeline.although
2647B
1-2
SUBSTATION
SUBSTATION
AND LOCAL
DISTRIBUTION
••II II 8 SIMPLE
........CYCLE UNITS
.L.L.L.L
LOW
LOAD
FORECAST
POWER PLANT
PRUDHOE BAY
TRANSMISSION LINE
LENGTH:450 MILES
WILLOW TO ANCHORAGE :50 MILES
ANCHORAGE
WILLOW
SUBSTATION
AND LOCAL
DISTRIBUTION
MEDIUM
LOAD
FORECAST
• •II ..•
15 SIMPLE ..........
CYCLE UNITS .L.L.L.L.L
.LJ..L.L.L
SUBSTATION
,~SUBSTAT.ON FAIRBANKS SUBSTAT.ON
AND LOCAL AND LOCAL
DISTRIBUTION DISTRIBUTION
.....FAIRBANKS TO HEALY:110 MILES
HEALY HEALY
TRANSMISSION LINE
HEALY TO WILLOW:170 MILES
EXISTING EXISTING
,~INTERTIE INTERTIE
-
-
ALASKA POWER AUTHORIT~
NORTH SLOPE GAS
FEASIBILITY STUDY
NORTH SLOPE SCENARIO
.....
~IGURE I-I
EBASCO SERVICES INCORPORATED
1-3
-
the size of the pipeline would be somewhat smaller than that proposed
for the Alaska Natural Gas Transportation System {ANGTS}.Electrical
power generation near Fairbanks ~ould use combined cycle plants
consisting of gas-fired combustion turbines,waste heat recover,y
boilers and steam turbines.A gas conditioning facility would be
required on the North Slope.
The Fa i rbanks generati"g scenari 0 is depi cted in Fi gure 1-2 whi ch shows
that five combined cycle and two simple cycle units are required to
meet the year 2010 medium load forecast {l400 MW}.The low load
forecast (700 MW)requi res three combi ned cycl e units.The Fai rbanks
generating scenario requires a 22 inch diameter gas pipeline from the
North Slope to Fairbanks and includes a natural gas distribution system
to meet residential and cOl1lIlercial heating needs.Three 345 kV
transmission circuits from Fairbanks to Anchorage are required for the
medium forecast and two for the low load forecast.Present worth of
costs of the electrical generating scenarios J excluding fuel costs,in
19B2 dollars is $5.2 billion (medium forecast)or $3.4 billion (low
forecast).The present worth of costs for the Fairbanks gas
distribution system is $0.9 billion for the medium load forecast and
$1.1 billion for the low load forecast.
The third scenario is contingent on the construction of a major natural
gas pipline from the North Slope to tidewater on the Kenai Peninsula.
Delays in the construction of ANGTS have renewed interest in such an
all-Alaska pipeline.This system is described in the Governor's
Economic Committee on North Slope Natural Gas Report (19B3)entitled
IITrans Alaska Gas System:Economics of an Alternative for North Slope
Natural Gas.II The Kenai electric generati ng scenari 0 incorporates the
anticipated energy demand from this system's tidewater facilities into
the Railbelt's demand forecasts.Fuel for the power plant will be
derived from a blend of waste gas from the conditioning facilities and
sales gas.A major transmission line would also be required from near
tidewater to the load center in Anchorage.The existing transmission
26478
1-4
MEDIUM
LOAD
FORECAST
LOW
LOAD
FORECAST
PRUDHOE BAY
CONDITIONING PLANT
GAS PIPELINE
LENGTH =450 MILES
SUBSTATION
AND 1.0CAL
DISTRIBUTION
SUBSTATION
AND LOCAL
DISTRIBUTION
EXISTING
INTERTIE
a=r ..a;.:3 COMBINED
CYCLE UNITSPOWERPLANT
FAIRBANKS TO HEAL.Y=110 MILES
WlLL.OW TO ANCHORAGE t 50 MILES
ANCHORAGE
FAIRBANKS
GAS DISTRIBUTION SYSTEM
TRANSMISSION LINE
t£ALY TO WIUOW =170 MILES
EXISTING
INTERTIE
WILLOW
SUBSTATION
AND LOCAL
DISTRIBUTION
HEALY
5 COMBINED -=-a;..a;.a;..a;.
CYCLE UNITS
....2 SIMPLE CYCLE .L .L
UNITS
SUBSTATION
AND WCAl
DISTRIBUTION
-
-
ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEASIBILITY STUDY
FAIRBANKS SCENARIO
FIGURE 1-2
EBASCO SERVICES INCORPORATED
1-5
------"--,-----------
"'""
.....
,-
line from Anchorage to Fairbanks would have to be up-graded to handle
the generating capacity.
The Kenai scenario (Figure 1-3)includes seven combined cycle units and
one simple cycle unit to meet the energy demand in 2010 for the medium
load forecast,and four combined cycle units and two simple cycle units
for the low load forecast.In order to provide a highly reliable
electric transmission system from Anchorage to Fairbanks,two parallel
345 kV circuits are required,even though a single circuit would be
adequate in the low load forecast.Underwater cable crossing of
Turnagain Armis cost effective,with two 500 kV circuits from Kenai to
Anchorage.Cost estimations,excluding the pipeline and gas processing
facilities as well as fuel costs in 1982 dollars,result in a present
worth of costs for the medium load fOt'ecast of $2.0 billion,and
$1.7 billion for the low load forecast.
1.4 RESULTS
This work has resulted in the development of several scenarios for
meeting the electrical generating needs of the Rai'lbelt region using
North Slope natural gas for fuel.Each scenario has been refined to
establish schedules of generating capacity additions consistent with
medium and low load forecasts through the year 2010.Chapter 2 and
Chapter 3 detail the North Slope Power Generation scenario for the
medium and low forecasts,respectively.Chapter 4 and Chapter 5 detail
the Fairbanks scenario,while Chapter 6 and Chapter 7 describe the
Kenai Power Generation scenario.
Engineering and cost evaluations of technologies capable of using
natural gas to generate electricity provide a consensus for the use of
gas fired combustion turbines.For the Fairbanks and Kenai scenarios,
the turbines are exhausted through waste heat recovery boilers to power
steam turbines.
26476
1-6
-
-
MEDIUM
LOAD
FORECAST
SUBSTATION .
AND LOCAL
DISTRIBUTION
HEALY
WILLOW
SUBSTATION
AND LOCAL
DISTRIBUTION
7COMBINED ...
CYCLE UNITS ...
I SIMPLE CYCLE .L
UNIT
FAIRBANKS
FAJRBANI<S TO HEALY:110 MILES
TRANSMISSION LINE
HEALY TO WIllOW:170 MILES
EXISTING
INTERTIE
WILLOW TO AtDiORAGE :50 MILES
ANCHORAGE
ANCHORAGE TO KENAI =87 MILES
KENAI
POWER PLANT
LOW
LOAD
FORECAST
SUBSTATION
AND LOCAL
DISTRIBUTION
EXISTING
INTERTIE
SUBSTATION
AND LOCAL
DISTR IBUTION
...·.........4 COMBINED
CYCLE UNITS.L .L 2 SIMPLE CYCLE
UNITS
"""'
ALASKA POWER AUTHORITY
NOATH SLOPE GAS
FEASIBILITY STUDY
KENAI SCENARIO
FIGURE 1-3
EBASCO SERVICES INCORPORATED
1-7
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All of the scenarios will require substantial construction of electric
transmission lines.A power plant on the North Slope separates the
generation and load centers by almost 900 miles.requiring special
transmission system design considerations to obtain a stable and
reliable system.Generation near Kenai.on the other hand.requires a
SOD kV underwater crossing of Turnagain Arm.
Socioeconomic and environmental effects of generating significant
amounts of electricity are substantial in both the construction and
operation of the system.Howe~er.no effect would appear to preclude
any of the scenari os.Both a ir and water poll uti on control measures
associated with gas fired combustion turbines are generally modest
compared to other technologies.
Cost estimates are provided for each forecast-of all three scenarios.
Because each scenario is distinctly different.except for providing the
required electricity.cost comparisons should not be the sole factor in
evaluating the desirability of any scenario.However,within the scope
of this study.Kenai generation shows the least cost because it does
not factor in the cost of the Trans Al aska Gas System and its
associated processes.The Fairbanks scenario is the most costly
because it includes a 450 mile natural gas pipeline.and a gas
conditioning facility on the North Slope.The North Slope scenario is
in the middle of the cost range and is characterized by the high
capital cost of constructing high voltage transmission lines to
Fairbanks.
2647B
1-8
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2.0 NORTH SLOPE POWER GENERATION
MEDIUM'LOAD FORECAST
The first scenario,under the medium load forecast,centers on a major
electric generating station on the North Slope at Prudhoe Bay,near the
source of natural gas used to fuel the station.By the year 2010,the
station would consist of 15 simple cycle combustion turbines capable of
generating almost 1400 megawatts (MW)of power to serve the Railbelt.
North Slope power generation does not requi re the constructi on of major
gas pipelines,but does require construction of 500 kilovolt (kV)
electric transmission lines from the North Slope to Fairbanks and
additional transmission lines of 345 kV from Fairbanks to Anchorage.
Detailed analysis of the transmission system shows that a stable and
reliable system can be designed despite the generation and major load
centers being over 800 miles apart.The total construction costs for
the system described are $4.2 billion,with total annual operation and
maintenance costs of $1.1 bill ion.The present worth of these costs
excluding fuel costs is $3.8 billion as of 1982.Environmental and
socioeconomic effects of this scenario are substantial,but none have
been identified which would preclude the project.
2.1 POWER PLANT
The power generation technology selected for the North Slope scenario
employs simple cycle combustion turbines utilizing 91 MW baseload,
combustion turbine generators.The criteria and parameters which
resulted in this selection are discussed in the Report on Systems
Planning Studies (Appendix B).
2.1.1 General
Development of a North Slope site for the required generating units,
construction and maintenance facilities,worker housing,and access
2601B
2-1
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facilities will be a major undertaking.In addition to continuously
expanding facilities for maintenance and operation,there will be
pennanent construction facilities and a semi-permanent construction
staff.
The scenario for utilizing simple cycle gas turbine-generators to
generate power at the North Slope requires fifteen 91 MW (nominal)
units for satisfying load demand under the medium load forecast.The
units would be added in increments beginning in 1993.On the average,
sl ightly "ess than one unit per year is required through the end of the
study period in 2010.Incremental and total required new generation
capacity for this scenario are summarized in Table 2-1.
The functional parts of the plant will consist of a gas supply
system(s),the turbine-generators,various auxiliary and support
systems,a central control facility,switchyards,and the northern
terminus of the transmission line.
A single simple cycle unit will require approximately a 90 ft x 150 ft
enclosure as shown in Figure 2-1.It is planned that the units be
installed side by side as shown in Figure 2-2 up to the maximum of 15
units required for the medium load forecast.The site will include the
138 kV switchyardbehind the'units and a 500 kV transmission line -
termination centered on the planned maximum plant site.A 300 ft wide
buffer area surrounding the site is planned,yielding a maximum total
site acreage of 90 acres.
2.1.2 Combustion Turbine Equipment
The combustion turbine plant design envisioned is based on using
currently available gas turbine units,rated by one manufacturer at
approximately 77 MW each.Various other manuf~cturers'turbines of
similar size could be used to satisfy the requirement of this study,
but it must be pointed out that the specific plant output and various
specific design parameters may be expected to change accordingly.
26018
2-2
-2601B
TABLE 2-1
NEW CAPACITY ADDITIONS AND FUEL REQUIREMENTS
NORTH SLOPE POWER GENERATION -MEDIUM LOAD FORECAST
2-3
J 1 1 }I l --l 1 .)1 J J
4IGO-4601f "VIC.
Ttt.t..N'!t1'i!l1r1111t
".--....lJKIL .....~~t1t
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TlWI~Pl.1
('l.)TWO ~1115o(1T")
ALASKA POWER AUTHORITY
'UN -11 HV NOHINAl RATlNG/SlH'U (Jel[PLANT NORTH SLOPE GAS
FEASIBILITY STUDY
SIMPLE CYCLE GAS TURBINE
GENERAL ARRANGEMENT
FIGURE 2-1
EBASCO SERVICES INCORPORATED
..0 ,
!>10 ,
s'»e
7&0 1".,0 ..
1110 H'4'0 ,~'.50 fa
'PIHrN~ON IMO._lD11'UT1'
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~8>UNI'•••0~'lIS ""'11.•110 ~, III''--,--.__.I~I........-,.......""-)~L~,_J
......_"'...__L I -t----If-------__-I _.---_fl__---_-•.--l ---.-.t _,
:--..-.I ~y 0"IC.,....'LO(,6,,~,+t*M~tN Itllt ~~~TIOlooI.~4'''~1'01.,..,
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]i J J "}1 fi j J J 1 __1_".1-,
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'fV.~IMION UN8
11'I,.QI(f,l e.-Nf'llS ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEASIBILITY STUDY
SIMPLE CYCLE GAS TURBINE
SITE PLAN
NORTH SLOPE
F'OURE 2-2
EBASCO SERVICES INCORPORATED
...
",...
-
-
-
At International Standards Organization (ISO)referenced conditions
(59°F and sea level)plant performance will consist of a net unit
output of 77 MW.The ISO heat rate of the units will be approximately
11,900 Btu/kWh (HHV).For the actual conditions existing at the ,North
Slope (average annual temperature of 9°F and sea level)the rating of
the turbines is approximately 91 MW and the heat rate is 11,500 Btu/kWh
(HHV)•
Each combustion turbine is a large frame industrial type with an axial
flow mUlti-staged compressor and power turbine on a common shaft.The
combustion turbine is directly coupled to an electric generator,and
can be started,synchronized,and loaded in about one half hour under
normal conditions.
The gas turbine generators are I'packaged"units and as such include all
auxiliary equipment.The package generally includes:
1.13.8 kV sWitchgear which houses the generator grounding
transformer,and generator air circuit breaker.
-
-,
,~
2.Nonsegregated phase (i so-phase)bus work which runs from the
generator to the main transformer.
3.A master control panel for overall operation and monitoring.
4.A transformer (13.8/4.l6 kV)sized to support the ancillary
load (estimated to be 2 MVA).
5.A 4.16'kV switchgear with air circuit breakers for other loads
(e.g.800 HP [horse power]cranking motor)•.The largest load
(gas compressor)is fed from the plant common 4.16 kV
switchgear.
6.Electrical protection equipment.
Each combustion turbine generator package also includes an inlet air
filtration system,fuel system,lubricating oil cooling system,and
various minor subsystems as required,furnished by the manufacturer.
2601B
2-6
.....
-
-.
The design parameters for each combustion turbine with generator are
presented in Table 2-2.Inlet air preheating using a heat exchanger
will also be necessary.
2.1.3 Fuel Supply
Annual fuel requirements for power generation at the North Slope will
be 6.5 BCFY (billion cubic feet per year)in 1993 and grow to 78 BCFY.
by 2010 for the medium growth forecast.Maximum potential firing rate
for the medium load growth scenario will be 2.5 x 10 5 SCFM (standard
cubic feet per minute)in the year 2010.
Fuel requi rements on a year by year basi s will vary with install ed
generating capacity and are shown in Table 2-1.These gas demands were
generated based on an average annualized unit heat rate of 11,500
Btu/kWh (HHV)for the simple cycle gas turbines at average ambient
conditions.
The HHV of the fuel gas is assumed to be 1046 Btu/SCF (LHV 942
Btu/SCF).These values reflect the fact that no gas conditioning
facilities will be required for the North Slope scenario.
The gas supply system will consi st of pipi ng from one or more of the
existing North Slope natural gas gathering centers,a pressure
reduction station and an in-plant distribution system.The supply and
distribution system will be designed for maximum flexibility to operate
any configuration of the available gas turbines.The pressure
reduction system will be required to assure a constant gas supply
pressure at 250 psig.
2.1.4 Switchyard
The circuit diagram of the power plant switchyard is shown in
Fi gure 2-3.Two generators wi 11 be connected to the two prima ry
windings of the 250 MVA 13.8/138 kV transformers.The bus arrangement
will use a breaker and a half scheme.Two 750 MVA 138/525 kV
2601B
2-1
..._~""""':'"",m ____
TABLE 2-2
COMBUSTION TURBINE WITH GENERATOR DESIGN PARAMETERS
Turbine Type:l!Simple-cycle.single-shaft,three bearing.
Generator Type:Hydrogen-cooled unit rated 130 MVA at 13.8 kV,with
30 psig hydrogen pressure at lODC.
Performance:-(Each Turbine -at.ISO Conditions)
-
Heat Rate (LHV)
Air Flow
Turbine Exhaust Temp
Turbine Inl et Temp
Inlet Pressure Drop
Exhaust Pressure Drop
Overall Dimensions
Combustion Turbine Features:
10,700 Btu/kWh
609 1bs/sec
995°F
1985°F
3.5 in.water
0.5 in.water
38 ft.wide by 118 ft.long by 32
ft.high
-
-
-
Accessories include starting motor.motor control center for all
base-mounted motors,lubrication system,hydraulic control system.
Excitation compartment complete with static excitation equipment.
Switchgear compartment complete with generator breaker.potential and
current transformers,disconnect link for auxiliary feeder.and a power
takeoff.
Fuel system capable of utilizing natural gas,mixed gas fuel,or liquid
fuel.
Fire protection system (low pressure C02)'
1.1 Based on General El ectri c MS700l.
2601 B
2-8
J 1 ')J 1 1 )j )J 1 )1 1 ))
13.1'kV
2 2 2 2 2 2 2 2 2 22 2 2 2 2,Z5MVA
500lcV
250 MVA
TYPICAL
750 MVA
TYPiCAL
IIJASCO IEAYlCU INCORPORATED
'10"'"1-3
NORTH SLOPE POWER GENERATION
MEDIUM LOAD FORECAST
SUBSTATION ONE LINE SCHEMATIC
ALASKA POWER AUTHORITY
NOATH SLOPE GAS
fEASIBILITY STUDY
r '
TO FAIRBANKS
200MVAR ~
TVPICAL n 1
TO FAIRBANKS
LEGENDoGENERATOR
~o."'"""TRANSFORMERoCIRCUITBREAkER
-"V\.Ar r?EACTOR±CAPACITOR
"
-
-
..-
-
autotransformers will supply each of the transmission line circuits.
Each of the transmission lines will have a circuit breaker.On the
line side of the circuit breakers will be the series capacitors and the
shunt reactors.This arrangement has the advantage of being flexible
as far as operation is concerned,and can be expanded easily.The
system's flexibility is demonstrated in Figure 2-4,which shows the
initial development associated with the installation of the first
generator.There are seemingly more circuit breakers than necessary in
this initial circuit;their.purpose is to facilitate future expansion
work.
The grounding mat of the switchyard is connected to four insulated 1000
kCM!!cables which terminate in a grounding rod system driven into
the sea floor.The ground mat is also connected to the two
counterpoises£/which run under the entire length of the transmission
1i nee
2.1.5 Power Plant Support System Descriptions
The auxiliary systems described in this section represent generally the
minimum necessary to operate a simple cycle combustion turbine
facility.These sy~tems include water supply,waste management,fire
protection,electrical,and lubricating oil systems.
Plant makeup water will be derived from an assumed existing lake of at
least 150 acres to supply the needs of two water systems:a potable
water system for the plant and the camp,and a service water system •.
The potable water system will be designed to supply water for the
maximum crew on hand through completion of the final unit.Service
water will be provided to all units for maintenance,construction uses
11 kCM stands for thousands of circular mils,a measure of the
cross-section of a cable.
2/Cou~terpoises are buried grounding cables,running under
transmission lines,which are necessary in areas with poorly
conducting soils.
2601B
2-10
-
750MVA
TYPICAL
13.8 kV
9~
13BkV
_-,500kV ,---...;;:;;500 kV
-
U"'-~---I
1'-200MVAR
TYPICAL
.-
CAPACITOR
CIRCUIT BREAKER
-
-
LEGENDoGENERATOR
~ORt't'W'\TRANSFORMER
D
--'V\/'v-REACTOR
~
ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEAStBl1.fTY STUDY
NORTH SLOPE POWER GENERATION
MEDIUM LOAD FORECAST
INITIAL STAGE Or=:SUBSTATION
DEVELOPMENT ;
EBASCO IERV.cES HCORPORATED
----~-----
~-
-
."..
-
and area cleaning.A water injection system should not be required for
NO x control on the North Slope ~see Section 2.4.1 for further
expl anati on)•
Waste control systems for the plant will consist of control and
processing through oil/water separation treatment of all floor drainage
from operating and maintenance areas.This treated effluent and
domestic wastes will be transported to an existing sanitary waste
treatment facility.Because the natural gas supply is low in sulfur
content,no sulfur dioxide (S02)emi ssions control will be required.
Due to the climatic conditions existing during most of the year,fire
protection will be based on standard halon systems rather than water
systems.Automatic halon systems will be installed for high risk
areas,and manual systems will be used for low risk areas.Also,each
system selected shall be compatible with any of the specific hazards it
is intended to combat.
A system for storing both clean and dirty lubricating oil shall be
included.The system will include a central storage area and portable
units capable of transporting,replacing,and/or cleaning the
lubricating oil in an operating gas turbine •
.2.1.6 Construction and Site Services
The construction and operation of a simple cycle power plant will
require a number of related services to support all work activities at
the site.These site services will include the following for the North
Slope power plant:
(1)Access
(2)Construction Water Supply
(3)Construction Transmission lines
·(4)Construction Camp
2601B
2-12
-
.-
-
I~
....
Access
Gravel roads'with a 5 foot minimum gravel base will be required to
connect the plant site with the existing road network at the North
Slope.It is expected that no more than 2 miles of new road
construction will be required.
It is anticipated that all personnel travel wi'll be by air with
pre-arranged commercial charter carriers to Deadhorse Airport.All
perishable goods,mail,and rush-cargo,will be flown in.Equipment
for construction will be flown in only under extraordinary
circumstances.
The site.will use the existing marine landing facilities during the six
week.IIthaw ll period to receive all major equipment and supplies.A
fenced interim storage area will be provi ded.The Dal ton Hi ghway (Haul
Road)from Fairbanks will be utilized for smaller shipments to the site.
Constructi on Water Supply
A compl ete water supply,storage and di stri bution system will be
installed.Due to the nature of the site,a heated and insulated
one-million gallon water storage tank will be incorporated into the
camp1s design,with one-half of this storage capacity dedicated to fire
protection needs.The water supply will be derived from an existing
lake.
Construction Transmission lines
Power requirements during the construction phase will be supplied by
constructing a 69 kV transmission line tapped from the area's existing
transmission system.
26018
2-13
-
-
..-
"""'
Construction Camp Facilities
A 200 (maximum)bed labor camp w,ill be provided unless an existing camp
can be utilized.All personnel housed in this camp will be on single
status.Provisions will be made to accommodate a work force of both
men and women by providing separate facilities.
The 200 bed camp w'ill accommodate the maximum requi red workforce for
those years when two turbines will need to be installed and started up
at the same time.For other years.a workforce of 50 to 100 (maximum)
is anticipated.This camp will"also be used to house operating
personnel.
2.1.7 Operation and Maintenance
Plant Life
£ach gas turbine will have a 30 year life expectancy.It is expected·
that the gas turbine units will be overhauled in accordance with
manufacturer's suggestions and good operating practice for the 1 ife of
the units.
Heat Rate of Units
Unit heat rates for the plants will vary.depending on ambient
conditions at the sites.It is common practice for gas turbine
manufacturers to quote heat rates in terms of the lower heating value
(LHV)of the fuel.However.since fuel is purchased based on higher
heating values (HHV).HHV figures are used in the balance of this
report.The site specific HHV heat rate is 11.500 Btu/kWh.ISO
conditions give a heat rate of 10.700 Btu/kWh (LHV)for base load
operation.
2601B
2-14
Scheduled and Forced Outage Rate
It is expected that the forced outage rate will be about 8 percent.
Operational experience on other plants indicates higher forced outages
in the first few years,but this is attributed to operational
adjustments required for a new plant.It is expected that a slight
increase in forced outages will occur as the plant ages.
Scheduled outages will be an additional 7 percent based on two periods
of regular semi-annual maintenance requiring shut down and one 5 week
period every three years for overhaul.
Operating Workforce
The number of personnel required to operate a plant of this type can
va ry wi de 1y,dependi ng on plant uti li zati on and system operati ng
practices.Based on Electrical Power Research Institute Operational
Development Group study figures,and considering the severity of
climate and operational failure,an on-du~operating and maintenance
workforce of 10 persons will be required starting in 1993,when one
unit is operating.This will grow as units are added until an on-duty
force of approximately 50 persons will be required for the 15 units
operating in 2010.Assuming a 12 hour shift and a 7-day-on,7~day-off
work schedule,the total required workforce will vary from 40 to 200
personnel.
2.1.8 Site Opportunities and Constraints
Climate is the single most important site characteristic affecting
design at the North Slope.As previously mentioned,the 77 MW rating
of the turbine is based on ISO conditions with an ambient temperature
of 59°F.As the ambient temperature decreases,the capacity of these
units increases.At OOf,the rated capacity of these units is 122
percent of the capacity at 59°f,or approximately 94 MW.The heat rate
decreases as the temperature decreases,and at O°F is 97.5 percent of
-.
2601B
2-15
----•__~.alll .'~liIIG ---_
r
I
-
that at 59°F.or approximately 11.600 Btu/kWh (HHV).Clearly a cold
climate site such as the North Slope offers some operational
performance advantages.This is especially true since the cold weather
also produces the annual peak loads for the Railbelt area.The average
annual temperature at the North Slope site is 9°F resulting in an
average annual unit capacity and heat rate of 91 MW and 11.500 Btu/kWh
(HHV).respectively.
The remoteness of the site combined with the climatic conditions
present the most significant problems to construction of this
scenario.The short construction season and the cost of constructi~n
at the North Slope generally dictate that as much prefabrication as
possible be performed prior to shipping units to the site.In addition
the arrival of shipments via barge will be delqyed until mid-summer
when the Arctic coast becomes free of ice.This further shortens the
construction season for shipped material s and may require storage over
winter for completion of construction the following summer.
2.2 TRANSMISSION SYSTEM
2.2.1 Overview of the System
For reasons of reliability.two parallel circuits have been
considered.The design criteria used in the study are presented in
Table 2-3.Additional details regarding system design and alternatives
are presented in Appendix D.The 450-mile length of the proposed
transmission system between the North Slope and Fairbanks will be
interrupted by two intermediate switching stations.one at Galbraith
Lake and one at Prospect Camp;this will establish three almost exactly
equa 1 150-mi 1e-l ong segments.
The two circuits will originate in the Prudhoe Bay/Oeadhorse area of
the North Slope.Each circuit will be supplied by two 750 MVA
transformers.protected by one circuit breaker and compensated with a
series capacitor bank and shunt reactor.The two circuits will be
2601 B
2-16
TABLE 2-3
TRANSMISSION LINE DESIGN CRITERIA
-Temperature range:
Wi nd 10ads:l!
Ice on conductor:
Snow on ground:
Cl earance to ground:
Tension in conductors:
Gradient on conductor
surface:2I
-60°F to +86°F
25 1bs per sq.ft above the Arctic Circle and
8 1bs/sq.ft.below it;2.3 lbs/sq.ft.at
+86 of
1.5"radial thickness with 8 lbs/sq.ft.wind
load at 32°F
36"north of the Arctic Circle and 24"south
of it
minimum 38 feet with snow on the ground
maximum 50%of rated tensile strength
maximum 18 kV per centimeter
,~!!25.0 1bs per square foot corresponds to 100 mph wind
8.0 lbs per square foot corresponds to 55 mph wind
2.5 1bs per square foot corresponds to 30 mph wind
Y To reduce corona losses and mitigate radio and television interference
26018
2-17
"~
,....
I ~
-
located on opposite sides of the road for the first 60 miles,to Pump
Station 2.South of the 60 mile mark,the line may not necessarily be
located on the two sides of the road.
The first switching station will be at Galbraith Lake approximately 150
miles south of Prudhoe Bay.Immediately south of the switching station
is a 30-mi1e portion of the route where the suitable terrain narrows,
possibly requiring the two circuits to be placed on single towers.In
the Atigun Pass area the slopes of the mountainside are not overly
rugged and the two circuits could be constructed a few hundred feet up
the slopes from the roadway.The Atigun Pass section is about 5 miles
long and reaches an elevati on of approximately 5,000 feet,the hi ghest
point of the transmission system.
The second switchi ng station will be located at Prospect Camp.It will
be identical to the one at Galbraith Lake.The line will cross the
Yukon River near the Yukon River Bridge,and will terminate in the
Fai rbanks area.
2.2.2 Voltage Selection
Three voltage levels were investigated in detail:500 kV AC,765 kV AC,
and +350 kV DC (see Appendix D).Each of these are capable of
transmitting the required power from the North Slope to Fairbanks.A
comparative cost study has been made using the methodology and cost
figures supplied by Commonwealth Associates (1978).The study
indicated that all three versions are within .:!.:.10%as far as capital
investment is concerned,which is within the expected range of accuracy
of these types of calculations.Therefore,all three can be considered
to be equal with respect to capital cost.The 500 kV alternative was
chosen for detailed cost estimating because this version represents the
most conventional approach and would likely have the best reliability.
2601B
2-18
-
-
i _
-
2.2.3 Towers
Tubul ar steel H-frame towers will be uti 1ized for the 1i ne;thei r
average height will be 90 feet and the average span will be 1000 feet.
There will be one dead end tower at approximately every 10 miles,or in
other tenns 2't of the towers wi 11 be dead end.if
Special consideration has been given to the crossing of the Yukon
River,about 1000 feet downstream from the highway bridge.The
required span will be approximately 3000 feet.At the selected
location the right (north)bank of the river is a flat,low floodplain,
but an approximately 300-foot hi 11 ri ses at the 1eft (south)bank
maki ng the desi go of the crossi ng easier.The span will be between two
lattice type dead end towers,one approximately 120 feet tall at the
north shore and the other approximately 100 feet tall on the top of the
hi 11 at the south end of the span.Thi s arrangement shou1 d pose no
greater hazard to waterborne traffic than does the bridge.
2.2.4 Conductors
Bundled conductors will be used for the line with two conductors per
bundle at 18 inches apart.Except for the Yukon River crossing,Chukar
conductor,a 1780 kCM ACSR~/conductor with a rated strength of
51,000 1bs and an outside diameter of 1.6 inches,should be used.With
a 1000-foot average span,the maximum sag will be 42 feet,which,with
a 95 feet tall tower,will provide adequate clearance to ground.In
satisfying all appropriate design criteria,the conductors will be
oversized with respect to current carrying capacity,consequently,one
circuit will be capable of carrying almost twice the reqUired medium
forecast power.The line will be provided with spacer dampers.
Jj A dead end tower is capable of withstandi ng a conductor break,
preventing structural failure of the transmission system from
proceeding beyond a dead end tower.
'f/ACSR -aluminum conductor,steel reinforced cable.
2601B
2-19
-
,.....
For the Yukon River crossing a special conductor with an ultimate
strength of 235~500 1bs may have to be ordered~such as 61x5 strand
A1umowe1d from the Copperwe1d Company.With the recommended towers~
mi nimum c1 earance to hi gh water will be 70 feet duri ng the surmner and
45 feet in the winter.Construction of the span will be done during
the winter months when ice cover penmits working over the river bed.
Special vibration studies must precede actual design and vibration
recording instruments must be installed after erection.
2.2.5 Insulators
Suspension insu1ators~such as type 5-3/4 11 x 1011 X 50 K 1b~will be
used.Two strings in a V configuration will hold the conductor
bundle.Norma11y~25 insulators are in each string.
For the first 60 miles from Prudhoe Bay fog type insulators will be
installed and the number of insulators in the strings will be double
that provided for the remainder of the route.A1so~fixed insulator
washing install ations will be provi ded at each tower~based on the
experience that $ohio has operating 69 kV lines at the North Slope.A
tank truck equipped with pumps~hoses and other equipment will perform
the annual washing in the fall.
2.2.6 Switching Stations
The two switching stations at Galbraith Lake and at Prospect Camp will
divide each of the line circuits into three~almost equa1~150 mile
long segments.The circuit schematic can be seen in Figure 2-5.The
arrangement is conventional.The intermediate switching stations will
make it possib1 e to switch a shorter segment out of the system in case
of a fault of a ci.rcuit~instead of the entire line length;this will
improve the stabi1ity~hence the re1iabi1ity~of the power system.
26018
2-20
TO PRUDHoe B~Y
11
I .,
.-
SOO1<\'
SOOKV
,-
II II
TO -PROSPECT CAMP
CAPACITOR
CfRCUIT 6REAKE~
-
LEGENDoGENERATOR
~ORt"¥n TRANSFORMER
o
-'\Ny-REACTOR
~
ALASKA POWER AUTHORITY
..OATH ILOPE GAS
FEAStBlLfTY enJOY
..
.NORTH SLOPE POWER GENERATION
MEDIUM LOAD FORECAST
TYPICAL TWO LINE
SWITCHING STATION SCHEMATIC
FIGURE 2-1
EBASCO 8ERvtCES ICORPORATED
-
2.2.7 Fairbanks Substation
The Fairbanks substation one line schematic is shown in Figure 2-6.
Two 500 kV line circuits,originating at Prudhoe Bay,will be connected
to the substation,through either one 1500 MVA or two 750 MVA 345/525
kV transformers.Three 345 kV circuits will leave the substation in
the direction of Anchorage.Two transfonners will provide power for
local area loads.The bus will be at 345 kV.The schematic shows two
static VAR compensators connected to the bus through dedicated
transformers.These static compensators will not necessarily be
located where shown in Figure 2-6;their connections to the system are
described in detail in Appendix D.The circuitry will use breaker and
a half or double breaker arrangements.The substation will be designed
so that the loss of one line,transfonner,circuit breaker or
compensator allows uninterrupted operation at full power.
2.2.8 Construction
Fi ve camps will be used to house the work force;each camp wi 11 serve
about a 90~ile section of the line for most of the construction
peri od.The number of people will vary between 41 and 155 per camp,
including the camp crew.The one exception is the period of building
the gravel pads,when a total of 2400 people will have to be housed
during the first summer of construction,which may require the opening
of additional camps~
A 100·X 100'gravel pad must be constructed to serve as the base·of
each tower,and every 18 miles 300'x 1200'pads will serve as
marshalling yards.Fifteen crews,with the aid of helicopters,can
erect the towers during a six month work period.The last operation
will be the stringing,which can be done by 5 crews,each with
helicopter assistance.The switcnyards will be constructed during the
time that the line is stringed.
2601B
2-22
J 1 ;)1 )'}1 )';)1 1 1 1 J J
7
.~
TO PRUDHOE BAY
1-j,
cOOMVARI'~
TYPICAL
500 kV
1-----1\1 \-..1 I'
rBASCO HRVlCEIINCOAPOAATED
ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEASIBILITY STUDY
''''''''I!t-e
NORTH SLOPE POWER GENERATlON
MEDIUM LOAD FORECAST
FAIRBANKS SUB8TATION SCHEMATIC
•.=iTATfC VAR COMPEN~ATOR·
:~
T38/1V
LOCAL
1---01111 ....., I
TTrekV
LOCAL T
TO ANCHORAGE
"""
LEGENDoGENERATOR
~OR"""'"TRANsrORMER
o C.IRCUIT BR£AK£R
-A.fV\,-REACTOR
i-CAPACITOR
Pad building will take place in one summer using two lO-hour shifts.
All other operations~except for surveying~.will each take six months
to perform and will be scheduled for fall and spring when the soil is
frozen~but when enough daylight is available to work at least one
8-hour shift.
2.2.9 Operation and Maintenance
The 1east reliable equipment will be the seri escapacitors.The cost
of a series compensated 500 kV line is about the same as that of an
uncompensated 765 kV line.The 765 kV alternative should be
investigated in more detail during detailed design of the line.The
trade-offs of not having series capacitors are wider rights-of-way~
increased problems due to contamination near Prudhoe Bay and increased
difficulties to construct the two circuits through Atigun Pass.
2.2.10 Communications
To provide adequate communications~a microwave system will be
installed.The t~rth Slope-Fairbanks line will require 16 repeater
stations.Five channels will be required~at least~one for
supervisory voice communication~one for data transmission~one for
relaying~one for service communication (below 4 kHz)and for alarm
(above 4kHz)~and one spare channel.Each repeater station will have a
radio transceiver to maintain voice communication between vehicles and
the dispatcher~using the service voice channel.
In addition~each transmission line circuit segment will be provided
with a line carrier~mainly to provide redundancy for vital transfer
tri p functi ons.
Though this project assumed a dedicated microwave system~the project
proponent may consider leasing microwave channels from ALASCOM.
Several options~inclUding direct satellite link~may be cost effective.
26018
2-24
-
-
-
-
--
-
-
-
.....
2.2.11 Siting Opportunities and Constraints
An inspection of the route indicated that most of the route should not
cause significant construction problems.However,three areas are of
some concern.The first 60 miles of the line south from the North
Slope is a tundra area;civil engineering design and construction
methods will have to be carefully investigated.Second,the grounding
problems posed by frozen soil require that a bare copper conductor,
called a counterpoise,be buried under each circuit along the entire
length of the transmission line and be connected to the ground mats of
all the substations and sWitching stations.Third,crossing Atigun
Pass,as mentioned earlier,will require careful design;here the
counterpoises may have to be routed farther from the circuits or be
carried on the towers.
2.2.12 Fairbanks to Anchorage Line
System studies perfonned by Ebasco (see Appendix D)indicate that
345 kV is a suitable voltage for this transmission line.This voltage
is compatible with the 345 IcV Intertie under construction.Therefore,
two new 345 IcV lines will be built and the Intertie will be extended
fully between Fairbanks and Anchorage.
At the time of writing this report,the detailed design of the Intertie
is available.Based on this information,the designs of the Intertie
extension and the two new lines are assumed to be the same as the
Commonwealth Associates (1981)design.The only additions will be the
intermediate switching station,shown in Figure 2-7,the series
capacitors and the shunt reactors.
2.2.13 Anchorage Substation·
The Anchorage substation will be the termination of the three 345 kV
line circuits.The substation bus will be 138 IcV,as can be seen in
Figure 2-8.All other details will be similar to that described for
the Fairbanks substation (Section 2.2.7).
2601B
2-25
II
TO F~IRBANKS
II
345 J<V
-
-
11 JI
545KV
II
CAPACITOR
c.IRcurr BREAKER
,~
LEGENDoGENERATOR
~ORf'n"'n TRANSFORMER
o
--A./\I'v-REACTOR
~
TO ANCHORAGE·
ALASKA POWER AUTHORITY
NORTH aLOPE GAS
FEAStBlLrTY STUDY
NORTH SLOPE POWER GENERATION
MEDIUM LOAD FORECAST
TYPICAL THREE LINE
\....SWITCHING STATION SCHEMATIC
FIGURE 2-7
fBASCO aERvtCES H:ORPORATEO
1 1 l J J ))j )1 1 '·1 --J })J
LEGENDoGENERATOR
~oR""""TRANSFORMERoCIRCUITBREAKER .
.JV\I'v-REACTOR
;k CAPACITOR
600 MVA
TYPICAL
TO FAIABANK6
~45k~1
LOCAL
I
.~TAT1C VAR COMPEN~ATOR
ALAaKA POWER AUTHORITY
NORTH aLOI'E GAS
PlASl8lLlTY ITUDY
NORTH SLOPE POWER OENERAT1ON
MEDIUM LOAD FORECAST
ANCHORAGE SUBSTATION 8CHEMATIC
'1eUM I-I
"AICO IfftYUI ~TtD
~~2.3 COST ESTIMATES
2.3.1 Construction Costs
2.3.1.1 Power Plant
.-
-
To support the derivation of total systems costs which are presented in
Section 2.3.4,order-of-magnitude investment costs were developed for
the major bid lines items common to a 77 MW (ISO conditions)natural
gas fired simple cycle combustion turbine and a 220 MW (ISO conditions)
natural gas fired combined cycle plant.These costs are presented in
Tables 2-4 and 2-5.The costs represent the total investment for the
first unit to be developed at the site.Additional simple cycle units
will have an estimated investment cost of $53,560,000 while additional
combined cycle units will have an estimated investment cost of
$218,820,000.The cost differential for additional units is due to
significant reductions in line items 1 and 15,improvements to Site and
Off-Site Facilities,and reductions in Indirect Construction Cost and
Engineering and Construction Management.
For the North Slope power generation scenario only simpl e cycle unit
costs have been used in the total system cost analysis (Section
2.3.4).Combined cycle costs were developed to support the cost
sensitivity analysis performed in conjunction with the system planning
studies (Appendix B).
2.3.1.2 .North Slope to Fairbanks Transmission Line
Transmission line order-of~agnitude investment cost estimates for the
North Slope to Fairbanks connection are presented in Table 2-6.These
estimates are based on two 500 kV lines of 1400 MW capacity with series
compensation,and two intermediate switching stations.
26018
2-28
--------------~~---_......._----------
~TABLE 2-4
ORDER OF MAGNITUDE INVESTMENT COSTS
<~77 MW SIMPLE CYCLE COMBUSTION TURBINE
(January,1982 Dollars)
.~-i
:Construction Total
Descri pti onl/
Materi al Labor Di rect Cost
~($1000)($1000)($1000)
f 1•Improvements to Site 385 4,800 5,185
2.Ea rthwork and Pi 1i ng 605 1,710 2,315
3.Circulating Water System 0 0 0
4.Concrete 25 450 475
:-5.Structural Steel Lifting
Equipment,Stacks 675 1,230 1,905
6.Buil di ngs 4,625 1,710 6,335
r !"""7.Turbine Generator 11 ,200 2,700 13,900
i '8.Steam Generator and Accessories 0 0 0
9.Other Mechanical Equipment 460 985 1,445
10.Pipi ng 200 2,100 2,300
~1l.Insulation and Lagging 30 450 480
12.Instrumentation 100 300 400
13.Electrical Equipment 1,500 10,800 12,300
P"'~14.Painting 5 90 95
15.Off-Site Facilities2/500 9,000 9,500
-SUBTOTAL $20,310 $36,325 $56,635
Freight Increment 1,015
TOTAL DIRECT CONSTRUCTION COST $57,650,....
Indirect Construction Cost 3,505
SUBTOTAL FOR CONTINGENCIES 61 ,155
Contingencies (15t)9,175
TOTAL SPECIFIC CONSTRUCTION COST 70,330
Engineering and Construction 2,300
Management
~
TOTAL CONSTRUCTION COST $72,630
1/The following items are not addressed in the plant investment pricing:
laboratory equipment,sWitchYard and transmission facilities,spare
parts,land or land rights,and sales/use taxes.
2/Costs for construction camp and construction workforce travel included
in Construction Labor category.
2601 B
2-29
---------_.-----~.--------------------------
TABLE 2-5
ORDER OF MAGNITUDE INVESTMENT COSTS
220 MW COMBINED CYCLE PLANT
(January,1982 0011 ars)
Construction Total
Descri pti on!!
Materi a1 Labor Di rect Cost
($1000)($1000)($1000)
r-
l.Improvements to Site 385 4,800 5,185
~2.Earthwork and Piling 1,860 5,460 7,320
3.Circulating Water System 0 0 0
4.Concrete 100 2,160 2,260
5•Structural Steel lifting.-Equipment,Stacks 900 2,400 3,300
6.Buildings 12,575 4,560 17,135
7.Turbine Generator 30,300 10,500 40,800
~8.Steam Generator and Accessories 9,600 18,000 27,600
9.Other Mechanical Equipment 5,625 11 ,705 17,330
10.Piping 1,470 12,000 13,470
11.Insulation and Lagging 290 2,880 3,170
12.Instrumentation 1,700 1,200 2,900
13.Electrical Equipment 4,500 36,000 40,500
14.Painti ng .25 360 385
F lto,15.Off-Site Facilities2/500 9,000 9,500
SUBTOTAL $69,830 $121,025 $190,855
Freight Increment 3,490
TOTAL DIRECT CONSTRUCTION COST $194,345
",...Indirect Construction Cost 8,760
SUBTOTAL FOR CONTINGENCIES 203,105
Contingencies (15%)30,465
TOTAL SPECIFIC CONSTRUCTION COST 233,570
Engineering and Construction 7,000
Management
TOTAL CONSTRUCTION COST $240,570
!I The following items are not addressed in the plant investment pricing:
laboratory equipment,switchYard and transmission facilities,spare
parts,land or land rights,and sales/use taxes..
~/Costs for construction camp and construction workforce travel included
in Construction Labor category.
2601B
2:"30
f .~
""'"
TABLE 2-6
ORDER OF MAGNITUDE INVESTMENT COSTS
NORTH SLOPE TO FAIRBANKS TRANSMISSION SYSTEM
(January 1982 Dollars)
Construction 2/Total
Description!!
Material Labor Oi rect Cost
($1000)($1000)($1000)
Switching Stations 33,335 26,100 59,435
Substations 58,655 44,941 103,596
Energy Management System 12,900 12,000 24,900
Steel Towers and Fixtures 822,212 873,012 1,695,224
Conductors and Devices 63,962 149,760 213,722
C1 eari ng 0 85,200 85,200
SUBTOTAL $991,064 $1,191,013 $2,182,077
Land and Land Ri 9ht~36,000
Engineering and Construction
Management 152,750
TOTAL CONSTRUCTION COST $2,370,827-
1/The investment costs reflect two 500 kV lines,1400 MW capacity with
series compensation and two intennediate switching stations.A 15
percent contingency has been assumed for the entire project and has been
distributed among each of the cost categories shown.Sales/use taxes
have not been included.
Construction camp facilities and services are included in the
Construction Labor cost categor,y.
Assumes a cost of $40,000 per mile (Peres American Inc.1981).
2601B
2-31
--------------~---_.----~--------------
2.3.1.3 Fairbanks to Anchorage Transmission Line
Transmission line order-of-magnitude investment cost estimates for the
Fairbanks to Anchorage connection are presented in Table 2-7.These
estimates are based on two new 345 kV lines,in parallel with series
compensation and an intermediate switching station.The investment
cost estimates also reflect upgrading from 138 kV to 345 kV of the
Willow-Anchorage and Healy-Fairbanks segments of the existing grid.
2.3.2 Operating and Maintenance Costs
2.3.2.1 Power Plant
The power plant operating and maintenance "(O&M)costs were derived to
support the system planning studies (Appendix B).They reflect a
review of figures from previous Rai1be1t studies,operation of other
utilities,and salary requirements and expendable materials.The O&M
costs for this scenario are estimated to be $0.0063 per ki110watt hour
(6.3 mils/kWh).
2.3.2.2 Transmission Line Systems
Annual operating and maintenance costs (January 1982 dollars)have been
developed for the scenario's required transmission line facilities and
total $35 million per year.These costs should be viewed as an annual
average over the life of the system.Actual O&M costs should be less
initially,and increase with time.
2.3.3 Fuel Costs
""'"
For the economic analyses which follow fuel costs were treated as
zero.This approach permits fuel cost and fuel price escalation to be-treated separately;and makes possible subsequent sensitivity analyses
of the Present Worth of Costs for this scenario based upon a range of
fuel cost and cost escalation assumptions.
2601B
2-32
,....,
....
TABLE 2-7
ORDER OF MAGNITUDE I NVESTMENT COSTS .
FAIRBANKS TO ANCHORAGE TRANSMISSION SYSTEM
(January 1982 Dollars)
Construction Total
Description!!
Material Labor Di rect Cost
($1000)($1000)($1000)
Switching Station 14,112 12,445 26,557
Substations 62,308 41,716 104,024
Energy Management Systems 12,300 10,960 23,260
Steel Towers and Fi xtures 216,495 305,085 521,580
Conductors and Devices 33,678 78,361 112,039
C1 eari ng 0 83,144 83,144
SUBTOTAL $338,893 $531,711 $870,604
Land and Land Ri ghtsY 0 0 27,600
Engineering and Construction 60,950
Management
TOTAL CONSTRUCTION COST $959,154
1.1 The investment costs ref1 ect two new 345 kV 1i nes,1400 MW capacity wi th
series compensation and an intenmediate switching station,and upgrading
of the Willow-Anchorage and Healy-Fairbanks segments of the existing grid
to 345 kV.
2/Assumes a cost of $40,000 per mile (Acres American Inc.1981).
2601B
2-33
---~_'_'--'$!4_a"--------.----
2.3.4 Total System Costs
The total system for the North Slope scenario,medium load forecast,
consists of simple cycle gas turbines and an extensive transmission
line system.No gas conditioning facilities or pipeline are
required.Total annual systems costs reflect the relative simplicity
of thi s system.
rr-
!.~
-
The methodology and assumptions utilized to derive the systems'costs
which are presented below have been previously described in the Report
on Systems Planning Studies (Appendix B).This methodolo"gy is
consistent with previous studies of electric generating scenarios for
the Railbelt,specifically Acres American,Inc.(l981),Susitna
~droelectric Project Feasibility Report and Battelle (1982),Rai1belt
E1 ectric Power Al ternatives Study.
Annual capital costs for the system are presented in Table 2-8.
Annual non-fuel operating and maintenance costs are presented in Table
;'"""2-9.These escalate at a rate of 2 percent/year above inflation.
Total annual systems costs are then summarized in Table 2-10 •
.-
For scenario comparisons,the present worth of total annual costs for
the North Slope medium load forecast has been calculated.Assuming a
3 percent discount rate and excluding fuel costs,the 1982 present
worth of costs is $3.7 billion.The values are in 1982 dollars •.....
2.4.ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS-
Development of a gas fired simple cycle combustion turbine facility at
the North Slope and transmission facilities to bring the energy to the
Rai1be1t region will engender a variety of significant environmental
effects.Precise quantification of environmental impacts will require
more detailed site-specific analysis.However,most major potential
26018
2-34
2601B
TABLE 2-9
TOTAL ANNUAL NON-FUEL O&M COSTS
NORTH SLOPE POWER GENERATION -MEDIUM LOAD FORECAST
(Millions of January,1982 Dollars)
2-36
...,
TABLE 2-10
TOTAL ANNUAL SYSTEMS COST
NORTH SLOPE POWER GENERATION -ro1EDIUM LOAD FORECAST
(Millions of January,1982 Dollars)
Calendar Capital o &M Total
Year Expendi tures Costs Expenditures
1983 O.O.o.
1984 O.O.o.
1985 O.O.O.
1986 O.O.O.
.-1987 O.O.O•
1988 O.O.O.
1989 1,803.3 O.1,803.3
1990 418.5 O.418.5
.~1991 842.6 O.842.6
1992 388.3 o.388.3
1993 O.38.8 38.8,....1994 53.6 38.8 92.4
1995 53.6 42.5 96.1
1996 53.6 46.3 99.9
1997 53.6 50.1 103.7-1998 o.53.8 53.8
1999 53.6 53.8 107.4
2000 o.57.7 57.7
2001 107.1 57.6 164.7
2002 o.65.1 65.1
2003 53.6 65.1 118.7
~2004 107.1 69.0 176.1
2005 53.6 71.4 125.0
2006 53.6 73.1 126.7
2007 53.6 74.8 128.4
~2008 O.76.6 76.6
2009 53.6 78.3 131.9
2010 O.80.0 80.0,.,..
Total $4,202.$1,093.$5,295.
Present
Worth @ 3%$3,156.$600.$3,757.
-
2601B
2-37
-
-
-
envi ronmental concerns related to thi s scenari 0 have been identified,
and may be categori zed as foll ows:
1.Ai r Resource Effects
2.Water Resource Effects
3.Aquatic Ecosystem Effects
4.Terrestrial Ecosystem Effects
,5.Socioeconomic Effects
Each of these subject areas is -discussed in the following subsections.
Power plant characteristics related to each of these subject areas is
summarized in Table 2-11.
2.4.1 Ai r Resource Effects
Development of the North Slope generating facility may be governed in
large part by air quality considerations.The federal Clean Air Act
and the Alaska rules for air quality control require the generating
facility to meet both atmospheric emission and ambient air quality
standards.Emission standards are defined in tennsof New Source
Performance Standards (NSPS)and Best Available Control Technology
(BACT).NSPS apply generically to combustion turbines,and set a
ceiling of emissl0n levels that cannot be exceeded.Because gas-fired
power plants are relatively clean,NSPS levels do not pose a constraint
to the development of this generating facility.BACT requirements are
detennined on acase-by-case basis,taking into account energy,
en vi ronmental,and economi c impacts,but are never less stri ngent than
NSPS.
The Prevention of Significant Deterioration (PSD)program protects
re1 ati vely c11ean areas from undergoi ng substantial degradation through
ambient air quality standards.The PSD increments for particulates and
sulfur dioxide have not been exhausted on the North Slope,and
2601B
2-38
TABLE 2-11
ENVIRONMENT RELATEO FACILITY CHARACTERISTICS
SIMPLE CYCLE COMBUSTION TURBINES
NORTH SLOPE POWER GENERATION -MEDIUM LOAD FORECAST
Air Envi ronment
,....,
-
-
-
Emissions
Particulate Matter
Sul fu r Di oxi de.
Nitrogen Oxides
PhYsical Effects
Water Environment
Plant Water Requirements
Plant Discharge Quantity.
Including Sanitary Waste
and Floor Drains
Land Envi ronment
Land Requirements
Plant and SWitchyard
Construction Camp
Socioeconomic Environment
Construction Workforce
Operating Workforce
2601B
Below standards
Below standards
Emissions variable within standards -
dry control techni ques woul d be used
to meet calculated NO~standard of
0.014 percent of total volume of
gaseous emissions.This value
calculated based upon new source
performance standards,facility heat
rate,and unit size.
Maximum structure height of 50 feet
50 GPM
Less than 50 GPM
90 acres
5 acres
Approximately 200 personnel at peak
construction (power plant only)
Approximately 200 personnel employed
in the year 2010 (power plant only)
2-39
___,_~m ._
....,
-
-
-
therefore do not constrain development.PSD increments for nitrogen
oxides,the major pollutant from combustion turbines,have not been
established.However,general PSD requirements dictate that Best
Available Control Technology be used to reduce nitrogen emission levels •
In the case of combustion turbines,BACT usually consists of using
water or steam injection techniques to control emission levels by
reducing combustion temperatures.Unfortunately,water or steam
injection in the Prudhoe Bay area causes undesirable levels of ice
fog.Furthermore,water or steam injection requires fresh water
supplies that are generally not economically available on the North
Slope.For these reasons,air quality regulatory agencies have not
defined BACT for the North Slope to include using water or steam
injection to control nitrogen oxides.Imposition of the requirement
for water or steam injection would add substantial costs and
significantly decrease the relative feasibility of this scenario.For
the purposes of this study it is assumed that water injection for NOx
control would not be required.
Even with no water injection requirement,air quality regulations would
not be likely to hamper installation of a gas-fired power plant in the
Prudhoe Bay area.However,a judicious siting effort would still be
necessary to avoid compounding any air pollution problems from existing
faci 1i ti es.
The construction of two 500 kV transmission lines between the North
Slope and Fairbanks would result in temporary air quality impacts.The
use of heavy equipment and other construction vehicles would generate
fugutive dust and exhaust emissions.Slash burning of material to
clear the right-of-way would produce emissions.The impacts from these
construction-related activities are expected to be small because the
emi ssions woul d be wi dely di spersed and occur in unpopul ated or
sparsely populated areas.
2601B
2-40
.,-
r ,~
-
-
The long term impacts from operation of the transmission lines are
expected to be negligible.The transmission lines would generate small
amounts of ozone which would be undetectable at ground levels and would
not cause problems with nearby vegetation.
The air quality impacts of constructing the transmission lines from
Fairbanks to Anchorage would result from activities similar to those
mentioned above.The impacts are expected to be of approximately the
same magnitude,although the amount of slash material to be burned
would be greater within this corridor and would be within proximity to
more popu1 ated areas.
The long term impacts from transmission line operations would be
similar to those of the Prudhoe Bay-Fairbanks transmission line
corri dor.
2.4.2 Water Resource Effects
The principal effects of the proposed generating facility on the water
resources of the Prudhoe Bay area include consumptive withdrawals from
freshwater sources (existing lakes)for potable supplies and
miscellaneous uses such as equipment wash-down.Because the generating
station will require minor volumes of water and will be served by
existing waste treatment facilities in the area,water resources
effects associated with these uses will not be significant.
For the medium load forecast,the site must have access to
approximately 50 gpm.Thi s water wi'll be taken from a nearby
freshwater lake of sufficient size so that the lake level and
hYdrologic balance is not significantly affected.
Transmission line construction between the North Slope and Fairbanks
may impact the quality of surface water resources through erosion
caused by land disturbance,but has little or no impact on water
supplies.Erosion control,especially in steep "terrain or areas of
2601B
2-41
-
,-
>r -
.~
susceptible soils,will be a major requirement imposed by permits
issued for right-of-way clearing and construction of the transmission
and related facilities,such as access roads.For example,the BLM
land use plan for the Prudhoe Bay-Fairbanks Utility Corridor (BlM 1980)
within which the transmission facilities would be rout~d,specifically
requires protection of stream banks and 1akeshores by restricting
activities to prevent loss of riparian vegetation.
Construction activities of the transmission lines between Fairbanks and
Anchorage wou1 d resu1 tin temporary impacts.The transmissi on lines
would cross several large rivers and numerous creeks,resulting in
temporary stream siltation,bank erosion,and the potential for
accidental spillage of lubricating oils and other chemicals into the
watercourses.Construction equipment working along streambanks or
crossing smaller streams could cause direct siltation of the
watercourse or cause indirect stream bank erosion and siltation through
the removal of vegetation and disturbance of permafrost.The effects
of siltation could alter stream channels,fill ponds,or damage aquatic
flora or fauna.
Significant effects on watercourses may be prevented by keeping
construction activities out of channels and away from stream banks.
Mea~ures that could be taken to avoid impacts include a set back of 200
feet from watercourses for transmission structures as well as
-establishment of a buffer strip along major watercourses to minimize
disturbance of vegetation and soils by construction equipment.In
cases where watercourses must be crossed by construction equipment,
such crossings could be conducted either during cold periods when the
stream is frozen or in a manner to limit pollution or siltation.The
use of he1 icopters to erect the towers will he1 p to mi nimize overall
construction impacts,since ground access requirements will be
minimized •
2601B
2-42
-
.-
-
2.4.3 Aquatic Ecosystem Effects
The major aqu~tic ecosystems of>the North Slope area include the marine
environment of the Beaufort Sea,the freshwater environments of the Sag
and Put Rivers and their tributaries,and estuarine habitats at the
rivers'mouths.Shallow lakes in the area do not support fish because
of complete freezing in the wintertime.Deeper lakes m~contain
resident species such as stickleback,but in general.knowledge of
these lakes is presently limited.In the rivers and estuaries,two
groups of fish are considered important:river fish such as the
grayling,and anadromous fish such as the the Arctic char and cisco.
The anadromous species descend local rivers at ice-breakup to feed in
the shallow littoral and sublittoral zone of the Beaufort Sea.They
ascend these rivers in the autumn and overwinter in deep pools.These
fish do not appear to undertake extensive migrations up the Sag or Put
Ri verso
These fishery resources could be affected by construction and operation
of a water supply intake,pipeline and access road construction.gravel
mining in rivers which could affect overwintering and general habitat
quality of the fish,and the need to cross larger river channels which
could interfere with fish passage.The latter item m~require the use
of special culverts to maintain migratory routes.Each of these
potential effects would be analyzed on a site-specific basis,and
detailed impact avoidance or mitigation measures developed.
Aquatic ecosystems within the transmission line corridor will also
require protection during project construction.Between the North
Slope and Fairbanks,the transmission lines m~cross as manY as 150
waterbodies which are utilized by fish for migration.rearing,
spawning,and/or wintering.Siting should avoid or minimize impact to
spawning areas in approximately 35 waterbodies and to wintering areas
in approximately 15 waterbodies.Information regarding specific
waterbodies of concern is presented in Appendix C,Report on Facility
Siting and Corridor Selection.
2601B
2-43
counterpoise (ground cable)construction may require excavation in
streambeds;this activity must ~e carefully planned (both spatially and
temporally)and monitored in accordance with individual permit
requirements.Conditions vary along the corridor,so that
environmental protection stipulations imposed by the regulatory
agencies will tend to be site-specific.
The transmission line corridor between Fairbanks and Anchorage makes as
many as 100 crossings of rivers and streams and comes within one mile
of numerous lakes and ponds.All of these waterbodies are important
habitat for endemic and anadromous fisheries.Impacts to fisheries
such as increased runoff and sedimentation could occur through clearing
of the right-of-way and crossing of watercourses by construction
equipment.The introduction of silt into .streams can delay hatching,
reduce hatching success,prevent swimup,and produce weaker fry.
Siltation also reduces the benthic food organisms by filling in
available intergravel habitat.
The potential adverse impacts can be reduced or el iminated through
construction scheduling.Construction of the transmission lines during
the winter would minimize erosion since the snow protects low
vegetative cover that stabil)zes soils.Ice bridges could be used by
construction equipment for crossing spawning areas,where possible.
Otherwise,where equipment would move through watercourses,
construction could occur during periods when there are no eggs or fry
in the gravel.
2.4.4 Terrestrial Ecosystem Effects
The North Slope area and specifically the river delta areas provide a
variety of habitats that are important to a diversity of plants and
animal s.Project rel ated impacts which requi re special consi derati on
inclUde:1)direct habitat elimination through the construction of
project facilities,access roads,and gravel borrow areas;2)indirect
26018
2-44
""",
,~
....
habitat elimination resulting from access roads which impede drainage
or which generate significant t~affic related dust;and 3)restrictions
to large mammal movements,especially caribou.
Construction of the powerplant,switchyard,construction camp and
related access roads will disturb approximately 65 acres of land.All
construction equipment should be restricted to areas covered with a
gravel pad.Tundra adjacent to the generating facility should not be
disturbed.
Because the generating facility will be located within the Prudhoe Bay
industrial complex,terrestrial habitat impacts engendered by this
project will be an added increment to those which have alreaqy occurred
as a result of oil field development.Final siting efforts should
include evaluation of the factors listed above,and will be the
mechanism through which highly significant terrestrial impacts can be
avoided,particularly the indirect impacts and migratory blockages.
The direct impacts of habitat removal due to facility construction are
generally unavoidable,but can be minimized through careful site
planning and construction management.
Construction of the transmission line facilities will require
~vegetative clearing in forested areas.Clearing should be restricted
_to the foll owi ng categori es of vegetati on:
1.Trees and brush which may fall into a structure,guy,or
conductor
,""'"
-
,-
2.Trees and brush into which a conductor may blow during high
winds.
3.Trees and brush within 20 feet of a conductor,and trees
within 55 feet of the line centerline.
4.Trees or brush that may interfere with the assembly and
erection of a structure.
26018
2-45
.-
Between the North Slope and Fairbanks,much of the area south of
Nutirwik Creek will require c1e~ring of trees within the right-of-way.
r-Because two lines will be built and trees within 55 feet of the line
.will be cleared,the total width of cleared vegetation will be 220
,,-feet.Over the length of the line,approximately 7000 acres will be
cl eared.
,-
I~
-
The transmission line corridor passes through a wide variety of
terrestrial ecosystems,and is adjacent to several major federal land
areas which have been protected,in part,for their wildlife values.
The Bureau of land Management (BLM)land use plan for the Utility
Corridor (BlM 1980)has identified several areas as containing critical
wildlife habitat.Specific management restrictions have not as yet
been formulated;however,measures may be required fora number of
areas.Details regarding these areas are given in Appendix C.
The land use plan also specifically requires protection of raptor
habitat and critical nesting areas.Protection of crucial raptor
habitats preserves the integrity of raptor populations and maintains
predator-prey relationships.
Facilities and long term habitat alterations are prohibited within one
mile of peregrine falcon nest sites unless specifically authorized by
the U.S.Fish and Wildlife Service,because of the endangered species
status of the peregrine falcon.
As the transmission line corridor generally avoids known nesting areas,
the restriction may only apply to material sites.Information
regarding specific raptor nesting areas and siting restrictions are
presented in Appendix C.
It is unlikely that the transmission line would be sited in or near
important Da11 sheep habitat.A primary concern is aircraft traffic
over critical wintering,lambing,and movement areas.Moose winter
browse habitat in the Atigun and Sag River valleys is limited to areas
2601B
2-46
r ~
I,,
-
F"
!
.....
of tall riparian willow.Habitat has already been eliminated by the
construction of TAPS and further destruction of this habitat should be
avoided or minimized.The willow stand along Oksrukuyik Creek,in
particular,should not be disturbed.
System design must allow free passage for caribou,but these animals
should not be a major consideration in siting.Carnivore/human
interaction is a major concern in facilities design and in construction
and operations methods,but not in siting considerations.
Line routing and tower siting should avoid or minimize disturbance of
the tree 1i ne whi te spruce stand at the head of the Di etri ch Va 11 ey,
which has been nominated for Ecology Reserve status.
For the Fairbanks to Anchorage transmission line approximately 80
percent of the corridor is located in forested areas (Commonwealth
Associates,1982).Assuming two additional lines are built and the
Intertie is extended,a total of about 8700 acres will be cleared.The
principal impacts associated with clearing a right-of-way and
construction of the transmission line are the alteration of existing
habitats and SUbsequent disruption of wildlife species that use those
habitats and disturbance to ~ndigenous fauna and bird populations.
Most big game species would relocate during the construction of the
transmission lines.The construction schedule should be flexible so as
to avoid construction near calving and denning sites.The moose,which
adapts to many different habitat types,would establish a subclimax
community in the cleared right-of-way.The distribution of caribou is
limited along the transmission line corridor but those that do occur
in the vicinity of the right-of-way would be displaced.The caribou,
however,generally util i ze habitats with low vegetative cover,
resulting in little alteration of caribou habitat.
Grizzly and black bears would relocate to avoid construction activity
along the right-of-way,except where construction occurs near a den
26018
2-47
.......-......................_------------,--------_.,----------
-
p-.
I 'i
site during winter dormancy.Construction activity near denning areas
should be avoided from October 1 through April 30.The alteration of
habitats could temporarily affect bear use of the right-of~ay but this
impact is expected to be relatively short-term.
Wolves within the vicinity of the right-of-way would also be displaced
during construction of the transmission line.While these impacts
would be temporary,long term impacts would occur to the wolf if their
principal prey species,such as caribou,sheep,and moose were
adversely affected.
Dall sheep occur only "at the northern end of the transmission line
corridor and would be impacted only minimally by construction
activities.The use of helicopters to construct the lines in the Mooqy
and Montana Creek drai nages coLi1 d severely di sturb sheep in the
vicinity of Sugarloaf Mountain.
The impact to the regional populations of any of the small game species
is expected to be negligible.Small game species are expected to
relocate during construction activities and re-invade the right-of-way
once construction is over.
In heavily forested areas along the corridor,the right-of-way clearing
could provide an improved habitat for most of the small game species
that utilize subc1imax communities.
Migratory waterfowl are susceptible to disturbance from construction
activities from mid-April to the end of September when they are nesting
and brood rearing.Construction activities should be restricted from
May through August in areas with active trumpeter swan nesting
territories.Collisions with transmission lines,guywires,and
overhead groundwires are another potential impact.To date,however,
the levels of avian mortality from line collision have not been
biologically significant (Beaulaurier et a1 1982).
26018
2-48
..-
-
-
..-
Furbearers are not expected to be greatly affected by construction
activities except during the inttial right-of-way clearing.Most
furbearers will either adapt to the presence of the cleared
ri ght-of-:way or undergo short-term impacts.The maintenance of a shrub
community in the right-of-way will reduce the loss of individuals.
The impacts on nongame mammals and birds are expected to be
insignificant.Some small mammals and nongame birds would undergo
population shifts during construction activities but populations are
expected to recover within one to two reproductive seasons.Raptors
may lose some habitat as a result of clearing.Benefits of a cleared
right-of-way could occur as some raptors could find that it provides
hunting habitat or hunting perches not previously available.
2.4.5 Socioeconomic and Land Use Effects
Potential socioeconomic and land use effects of the North Slope
scenari 0 i ncl ude both temporary impacts rel ated to the i nfl ux of
workers and permanent land use impacts.
Since the generating plant would be located within the Prudhoe
Bay/Oeadhorse industrial complex,the in-migrating work force would not
significantly affect the social and economic structure of the region.
The work force requirements are small in comparison to the existing
size of the transient workforce in the Prudhoe Bay region.For 5
months of each year duri ng the peri od 1993 through 201 0 a maximum of
200 employees will be needed to assemble the prefabricated units of the
plant.Housing facilities would be provided for the employees at the
adjacent construction camp.During off~ork periods,the majority of
the employees would spend time outside of the borough.The operations
work force is expected to be approximately 150 and will reside in the
labor camp.The spending of wages earned by the employees within the
North Slope Borough is expected to be minimal due to the transience of
the work force.
26018
2-49
------------_.-----'-------------------------------
.....
The use of land for an electrical generating plant would be compatible
with the land uses of the indus~rial enclave.The Coastal Zone
Management Program for the North Slope Borough has del ineated zones of
preferred development.Pennanent facilities are allowed in the
industrial development zone,consisting of the existing Prudhoe
Bay/Deadhorse complex and the Pi pel ine/Haul Road Utility corridor
(North Slope Borough 1978).The generating plant would be located
within the preferred development zone.
Within the Prudhoe Bay/Deadhorse complex,the plant would be located to
minimize interferences with existing or planned facilities,including
buildings,pipelines,roads,and transmission lines.Land ownership
and lease agreements will lilllit the land available for the electrical
generating facility.
Socioeconomic and land use impacts related to construction and
operation of transmission facilities between Prudhoe Bay and Fairbanks
will be strictly controlled as a result of the gUidelines and
constraints for development withi n the designated util ity corridor.
Construction employees would be housed either at the pump stations or
the pennanent camp facilities constructed for the trans-Alaska oil
pipeline.Construction actiyities would be consistent with the land
use criteria developed by the BLM.The BLM has prepared land use plans
for the utility corridor between Sagwon Bluffs and Washington Creek.
Road and highway crossings would be minimized,and areas of existing or
planned mineral development would be avoided.
Pennanent faci 1iti es woul d be con sol i dated at carefully sel ected
locations in the vicinity of Livengood Camp,Yukon Crossing,Five Mile
Camp,Prospect,Coldfoot,Chandalar,and Pump Station #3.Existing
facilities such as work pads,highways,access roads,airports,
material sites and communications would be used to the maximum extent
possible.
2601B
2-50
-
-
......
The schedule for constructing the transmission lines is approximately 3
years with activities occurring ~ain1y during the autumn and spring of
each year.A peak work force of 2400 employees would be required
during the first year of construction when the pads would be built.and
in sUbsequent years the total work force would be substantially reduced
to approximately 500 in the second year.600 in the third year.and 670
in the final year.It is expected that these workers will be hired
from the Anchorage and Fairbanks union hiring halls.
Development of additional transmission facilities between Fairbanks and
Anchorage would engender potentially more significant socioeconomic and
land use impacts,since this segment is more populated and subject to
future land use development.Temporary campsites would be provided to
house the work crews at locations accessible by the Parks Highway or
the Alaska Railroad.The work force requirements would be lower for
this corridor because pads would not need to be constructed.The
schedule for constructing the transmission lines is approximately 22
months.A peak work force of approximately 520 employees would be
required during the last 6 months and the average work force would be
approximately 300.These estimates do not include the helicopter
crews.It is assumed that the project would utilize the labor pools of
Fairbanks and Anchorage.
Impacts to local cOl'll1lunities would be minimized through careful siting
of the temporary work camps.It is expected that the work camps would
be self-contained in order to keep to a minimum interaction between the
construction workers and the local residents.The project is expected
to have minor primary economic benefits since few,if any.residents
would be employed on the project.
land use impacts could include encroachment of the project on
residential areas as well as preclude future residential development
land available for homesteading.The most significant potential impact
wou1 d be the crossi ng of recreati on 1ands and the sUbsequent effects on
recreation and aesthetic val ues these 1ands are meant to preserve.
26018
2-51
-
The potential aesthetic impacts of the proposed new and additional
transmission facilities are significant.The cumulative effects of
these facilities and previous linear developments (e.g.TAPS)could
result in significant degradation of the aesthetic character of
pristine wilderness landscapes.The visibility of the transmission
lines from existing travel routes (Dalton Highw~,Parks Highway,etc.)
will vary dependi ng on di stance,topography and i nterveni ng
vegetation.Special care would be taken in selecting final route
alignments in proximity to areas of special visual significance.such
as national parks,or high visual sensitivity,such as areas within the
viewing range of motorists on the Parks Highw~.In locations where
visual impacts cannot be avoided through careful routing or tower
spotting.mitigating measures.such as the use of non-reflective paint
or vegetative screening,can be employed.
26018
2-52
---------$------
-
-
-
.-
-
3.0 NORTH SLOPE POWER GENERATION
LOW LOAD FORECAST
The North Slope power generation scenario,under the low load forecast,
is conceptually the same as the medium growth case,except that units
are phased in at a slower rate.By the year 2010,eight simple cycle
combustion turbine units are required to produce 728 MW.The electric
transmission system requires two 500 kV lines;however,series
capacitors are not required to ensure system stabil ity.Total system
cost is estimated to be $3.3 billion,with annual operation and
maintenance costs of $0.7 billion.The present worth of these costs
excluding fuel costs is $2.7 billion as of 1982.Environmental effects
of the project are substantial,but would not preclude construction.
Information presented in this section is designed to highlight only
those conditions which are significantly different from those of the
medium load forecast presented in Chapter 2.
3.1 POWER PLANT
This scenario requires eight 91 MW simple cycle gas turbines to satisfy
the low load forecasted demand.The first of these will go on line in
1996 and the eighth in 2010.Additions are summarized in Table 3-1 and
scenario details are addressed in Appendix B.Annual fuel requirements
for power generati on will start at 6.60 BCFY in 1996 and grow to 47.2
BCFY in 2010.The maximum potential firing rate in 2010 will be
approximately 1.33 x 105 SCFM.Fuel requirements on an annual basis
are also shown in Table 3-1.
With the exception of the switchyard,all details of individual plant
items are identical to those described for the medium load case in
Section 2.1.The sWitchyard for this scenario differs from the medium
forecast design (Figure 2-3)in that there are no series capacitors
2589B
3-1
."'"'
..2589B
TABLE 3-1
NEW CAPACITY ADDITIONS AND FUEL REQUIREMENTS
NORTH SLOPE POWER GENERATION -LOW LOAD FORECAST
3-2
-
-
-
,~
-
"'"
-
installed and the facility is smaller in size.The circuit diagram is
shown in Figure 3-1.Only four 13.8/138 kV generator transformers are
needed,and each transmission line circuit is supplied by only one 750
kVA 138/500 kV transformer.The initial installation is essentially
the same as in Figure 2-4 except that the series capacitors are not
required.
Personnel required for operation and maintenance will be less for this
scenario than for the medium load forecast.Ten on-duty personnel will
be required in 1996 for the first unit.This number will increase to
approximately 35 on-duty personnel when 8 units are operating in 2010.
The total two-shift,full year,work force would therefore range from
40 to 140 for the study period.
3.2 TRANSMISSION SYSTEM
The North Slope to Fairbanks,and the Fairbanks to Anchorage
transmission systems for the low load forecast scenario do not differ
significantly from the medium forecast designs.A voltage of 500 kV is
cost effective for the line between the North Slope and Fairbanks;
however,for this case,series capacitors will not be needed.For the
Fairbanks-Anchorage section,two 345 kV lines with series compensation
are sufficient.That is,one new 345 kV 1ine will be constructed and
the Healy-Fairbanks and the Willow-Anchorage segments of the existing
grid will be upgraded from 138 kV to 345 kV.
The number and sizes of the intermediate switching stations remain
unchanged.There are two such stations on the 500 kV line (without a~
series capacitors),at Galbraith Lake and at Prospect Camp.There is
only one sWitching station on the 345 kV line from Fairbanks to
Anchorage,but in this case it has to be at the midpoint of the line,
i.e.,some 30 miles north of the Devil's Ca~on sWitchyard of the
medium forecast scenario.
The substatJon at Fairbanks and Anchorage are slightly scaled down from
those described in Section 2.3 and Figures 2-5 and 2-6.
2589B
3-3
J l
LEGEND
250 MVA
TYPICAL
500kV
TO FAIRBANKS
0 GENERATOR
=oRI"'"''\"'' TRANSFORMER
0 CIRCUIT BR£AKER
-'\fV\r. REACTOR
l CAPACITOR
750MVA
TYPICAL
200 MVAR TYPICAL
II
TO FAIRBANKS
J J
ALASKA POWER AUTHORITY
NORTH ILOPE GAS
'EASIBILITY STUDY
NORTH SLOPE POWER GENERATION
LOW LOAD FORECAST
SUBSTATION ONE LINE SCH!MAT1C
,ICJIME S -1
IIAICO IERVICES ltCOAPORATED
,"""
3.3 COST ESTIMATES
3.3.1 Construction Costs
,-
-.
-
-
The capital cost of each simple cycle gas turbine is the same as that
presented in Section 2.3 for the medium load forecast.
The order of magnitude investment costs of the transmission line
systems are presented in Table 3-2 and 3-3.Table 3-2 presents the
estimates for two 500 kV,700 MW capacity lines without series
compensation,and two intermediate switching stations.Table 3-3
contains the estimates for one new 345 kV line,700 MW capacity,with
series compensation and an intermediate switching station,and the
required upgrading of the Willow-Anchorage and Healy-Fairbanks
transmission lines.
3.3.2 Operating and Maintenance Costs
Power plant operating and maintenance (0 &M)costs are the same for
both the medium and low load forecasts,.6.3 mils/kWh.Transmission
line 0 &Mcosts are estimated to be $30 million per year.These costs
should be viewed as an annual average over the life of the system.
Actual O&M costs should be le$s initially and will increase with time.
3.3.3 Fuel Costs
For the economic analyses which follow fuel costs were treated as
zero.This approach permits fuel cost and fuel price escalation to be
treated separately;and makes possible subsequent sensitivity analyses
of the Present Worth of Costs for this scenario based upon a range of
fuel cost and cost escalation assumptions.
3.3.4 Total System Costs
The total system for the North Slope low load forecast,like the North
Slope medium growth forecast,consists only of simple cycle combustion
turbines and a transmission line system.
2589B
3-5
------,----------------~-----_.--~-
TABLE 3-2
ORDER OF MAGNITUDE INVESTMENT COSTS
NORTH SLOPE TO FAIRBANKS TRANSMISSION SYSTEM
(January 1982 Dollars)
~,
Total
,~Material Construction Labor 2/Di rect Cost
Descri ptionl!($1000)($1000)($1000)
{'-
Switching Stations 20,440 19,253 39,693
Substations 35,518 28,694 64,212
Energy Management System 12,900 12,000 24,900
f Steel Towers and Fixtures 822,212 873,012 1,695,224
"\
Conductors and Devices 63,962 149,760 213,452
C1 earing 85,200 85,200
SUBTOTAL $954,762 $1,167,919 $2,122,681
Land and Land Right~36,000
-Engineering and Construction 148,600
Management
-TOTAL CONSTRUCTION COST $2,307,281
-1/The investment costs reflect two 500 kV lines,700 Mh'capacity without
series compensation and two intermediate switching stations.A
15 percent contingency has been assumed for the entire project and has
~been distributed among each of the cost categories shown.Sa1es/us~
.taxes have not been included.
-
2/
3/
2589B
Construction camp facilities and services are subsumed in the
Construction Labor cost category.
Assumes a cost of $40,000 per mi 1e (Acres Ameri can Inc.1981).
3-6
TABLE 3-3
ORDER OF MAGNITUDE INVESTMENT COSTS
FAIRBANKS TO ANCHORAGE TRANSMISSION SYSTEM
(January 1982 Dollars)
Construction 2/Total
'""'"Descri ptionl!
Material Labor Di rect Cost
($1000)($1000)($1000)
~
Switching Station 8,857 8,414 17,271
~Substation and Switching 32,958 30,872 63,830
Station
Energy Management Systems 12,300 10,960 23,260
"'"'
Steel Towers and Fixtures 129,214 182,083 311 ,291
~Conductors and De vi ces 20,049 53,183 73,232
C1eari ng 41,572 41,572
,....,
SUBTOTAL $203,378 $327,084 $530,456
Land and Land Right~/14,400
"""
Engineering and Construction~37,130
Management
f"'"
TOTAL CONSTRUCTION COST $581,986
The investment costs reflect one new 345 kV line,700 MW capacity
without series compensation and an intermediate switching station,and
upgrading of the Willow-Anchorage and Healy-Fairbanks segments of the
Intertie to 345 kV.
Assumes a cost of $40,000 per mile (Acres American Inc.1981).
2589B
3-7
_................_"'_"!'L"'..."""...------~~----------------------
,....
~,
-
,-
JlJ!lIlIOl.
-
I~
The methodology and assumptions utilized to derive the systems·costs
which are presented below have been previously described in the Report
on Systems Planning Studies (Appendix B).This methodology is
consistent with previous studies of electric generating scenarios for
the Railbe1t,specifically the Acres American,Inc.(1981),Susitna
Hydroelectric Project Feasibility Report and Battelle (1982),Rai1be1t
Electric Power Alternatives Stuqy.
The annual capital expenditures are presented in Table 3-4.Annual
non-fuel O&M costs are presented in Table 3-5.The summary of all
annual costs in presented in Table 3-6.The 1982 present worth of
costs for this scenario (in 1982 dollars)is-$2.7 billion,exclusive of
fuel costs.
3.4 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS
The power plant for the low load forecast will consist of 8 simple
cycle units,in contrast to 15 units for the medium load forecast.
Most environmental impacts will therefore be correspondingly smaller
than the medium load forecast.Environment related power plant
characteristics are sUlmIarized in Table 3-7.
Air emissions will be approximately one-half the medium growth value
and will not pose constraini n9 ai r quality problems.Approximately 25
gpm of fresh water will be pumped from a nearby lake to provide
equipment wash-down and potable water supplies.Wastewater discharges
will be less than 25 gpm and will be discharged to the existing
facilities in the area.
Aquatic resources,as for the medium load forecast,will not be
significantly affected.Plant acreage,including the construction camp
and switchyard,will be approximately 65 acres,as compared to 95 acres
for the medium load forecast.Terrestrial impacts,such as tundra
disturbance and habitat elimination,are correspondingly less.
2589B
3-8
TABLE 3-4
TOTAL ANNUAL CAPITAL EXPENDITlIR"ES
NORTH SLOPE POWER GENERATION -LOW LOAD FORECAST
(Millions of January,1982 Do11ars)l!
Calendar Electricity Generate~Transmission
Year Un,t A Umt B Line Total
1982 O.O.O.O.
1983 o.O.O.O.
1984 O.O.o.O.
1985 O.O.O.O.
"....1986 O.O.O.O.!
1987 O.O.O.O.
1988 O.O.O.o.
,-1989 O.O.O.O.
1990 O.O.O.O.
1991 O.O.O.O.
~1992 O.O.1,540.1 1,540.1
1993 O.O.358.0 358.0
1994 19.073/O.704.6 723.7
1995 53.56 O.286.4 340.0.-1996 53.56 O.O.53.6
1997 o.O.O.O.
1998 O.o.o.O.
F'"1999 O.O.O.O.
2000 O.o.O.o.
2001 53.56 O.O.53.6
.2002 53.56 o.o.53.6.-2003 O.o.O.o.
2004 53.56 53.56 O.107.1
2005 O.O.O.O.
~2006 O.o.O.O.
2007 53.56 o.O.53.6
2008 O.o.O.o.-2009 53.56 o.o.53.6
2010 O.O.o.O.
TOTAL $394.$54.$2,889.$3,337.
~
~11 Values as calculated are shown for purposes of reproducibility
only,and should not be taken to imply the indicated accuracy ~
significant figures./
~2/Unit A refers to the first unit built in a given year and U~~B
to the second unit built./
3/I
Construction of camp site and site preparation for all ~nits.
!
\,
~3-9
25898
!PlD.
-
'l".MI!!!!!I'.....;
2589B
TABLE 3-5
TOTAL ANNUAL NONFUEL OPERATING AND MAINTENANCE COSTS
NORTH SLOPE POWER GENERATION -LOW LOAD FORECAST
(Millions of January.1982 Dollars))
3-10
ft=!li
TABLE 3-6
TOTAL AtmUAL COSTS
NORTH SLOPE POWER GENERATION -LOW LOAD FORECAST
(Millions of Janua~,1982 Dollars))
~
Calendar Capital o &M Total,.,..
Year Expenditures Costs Expenditures
(-1982 O.o.o.
1983 O.o.o.
1984 o.o.o.
1985 O.O.o.
1986 O.O.o.
1987 o.O.o.
1988 O.O.O.
!~1989 o.O.O.
1990 O.O.O.
1991 O.O.O.
1992 1,540.1 O.1,540.1
1993 358.0 o.358.0
1994 723.7 o.723.7
1995 340.0 O.340.0
r .-1996 53.6 33.8 87.4
1997 O.37.5 37.5
1998 o.37.5 37.5
......1999 O•37.5 37.5
2000 o.37.5 37.5
2001 53.6 .37.5 91.1
~2002 53.6 41.3 94.9
2003 o.45.1 45.1
2004 107.1 45.1 152.2
2005 o.52.6 52.6
;~2006 O.52.6 52.6
2007 53.6 52.6 106.2
2008 O.55.4 55.4--2009 53.6 56.2 109.8
201 0 O.57.0 57.0
~~Total $3,337.$679.$4,016.
Present
Worth @ 3~$2,345.$360.$2,705.
~
25898
3-11
TABLE 3-7
ENVIRONMENT RELATED POWER PLANT.CHARACTERISTICS
NORTH SLOPE POWER G~NERATION -LOW LOAD FORECAST
Ai r Envi ronment
Emissions
Particulate Matter
Sulfur Dioxide
Ni trogen Oxi des
Pl'\Ysical Effects
Water Environment
Pl ant Water Requirements
Below standards
Below standards
Emissions variable within standards -
dry control techniques would be used
to meet calculated NO f standard of
0.014 percent of tota volume of
gaseous emissions.This value
calculated based upon new source
perfonnancestandards,faci 1i ty heat
rate,and unit size.
Maximum structure height of 50 feet
25 GFM
Plant Discharge Quantity Less than 25 GPM
Including Sanitary Waste
and Floor Drains
Land Environment
-
Land Requirements
Plant and Switc~ard
Construction Camp
Socioeconomic Environment
Construction Workforce
Operating Workforce
2589B
60 acres
5 acres
Approximately 115 personnel at peak
construction
Approximately 140 personnel
3-12
-_................_.-._---------------_...-------------------
Impacts associated with the transmission line from the North Slope to
Fairbanks are identical to those discussed for the medium load forecast
F"'"(Section 2.4).From Fairbanks to Anchorage only one line in addition
to the Intert ie will be necessary,in contrast to two new 1i nes for the
medium load forecast.Cleared acreage within the right-of-way will be
approximately 5200 acres,as compared to 8700 acres for the medium load
forecast.Impacts associated with vegetative clearing,including
erosion,sedimentation,and habitat disturbance,are correspondingly
less than those discussed in Section 2.4.
Construction of the project according to the low demand forecast would
resu1 tin a smaller workforce than under the medium demand forecast as
well as a shorter work schedule.The construction workforce is
forecasted to be 115 employees,or a 40 percent reduction over the 200
employees forecasted for the medium growth scenario.The operations
workforce is predicted to be 140 persons,whi ch is 70 percent of the
workforce requirements of the medium growth forecast.
Construction of the first generation unit would begin in 1996 compared
to 1993 under the medium growth forecast.For five months of each of
eight years during the period 1996-2010 a prefabricated unit of the
p1 ant would be assembled.Ouri ng off-work peri ods,the majori ty of the
employees would spend time outside of the North Slope Borough.The
spending wages earned by the employees within the borough is expected
to be minimal due to the transience of the workforce.
Despite the differences in workforce requirements and schedule between
the low and medium growth forecasts,the socioeconomic impacts would be
expected to be similar.The relatively low level of impact can be
attributed to the location of the generating plant within the Prudhoe
Bay/Deadhorse i ndustri a1 complex,which is i sol ated from conuTluniti es.
The workforce requirements and schedule for construction of the
transmission lines is almost identical to that of the medium forecast
scenario,and,therefore,socioeconomic impacts will be essentially the
same as those discussed in Section 2.4.
2589B
3-13
-
-
.....
-
.-
-
-
-
4.0 FAIRBANKS POWER GENERATION
MEDIUM LOAD FORECAST
Fairbanks power generation,under the medium load forecast,requires a
gas conditioning plant on the North Slope,a medium diameter pipeline
to the Fairbanks area,an electric generating station at the pipeline
terminus,and electrical transmission capacity between Fairbanks and
Anchorage.The North Slope gas conditioning plant will remove carbon
dioxide (12%by volume of the raw gas)and natural gas liquids.
Initial and final peak delivery volumes are anticipated to be 230
MMSCFD and 407 MMSCFD,respectively,using a 22 inch diameter pipeline
operating at 1260 pounds per square inch of pressure.The pipeline
will be buried.Initially,three gas compressor stations along the
pipeline route will be required,increasing to 10 in the year 2010 •
The electric generating station necessary to produce almost 1400 MW of
capacity in 2010 will consist of 5 combined cycle units,each
consisting of two gas fired combustion turbines paired with two waste
heat recovery boilers and one steam turbine generator,and 2 simple
cycle gas turbines,which can be paired with waste heat recovery
boilers to form a sixth combined cycle unit after 2010.Transmission
lines to carry the power to the load center in Anchorage will require
two additional (total of 3)345 kV lines from Fairbanks to Anchorage.
This scenario also includes the construction of a natural gas
distribution system in Fairbanks to serve residential and commercial
space and water heating needs.Forecasting a fuel demand which
replaces existing fuels is speculative,but highest demand (including
growth)is based on 100 percent penetration of the potential market.
In Fairbanks, in 2010,this is estimated to be as much as 63 MMSCFD.
2648B
4-1
Costs for shared facilities have been apportioned between the electric
generating facility and the residential/commercial gas distribution
system.Gi ven thi s apportionment,constructi on of the gas conditioni ng
facilities,gas pipeline,power generating facilities and transmission
systems,is estimated to cost $6.2 billion.Total annual operation and
maintenance costs are estimated to be $0.8 billion.The present worth
of these costs excluding fuel costs is $5.2 billion.Construction costs
for the Fairbanks gas distribution system total $1.1 billion,with total
annual operating and maintenance costs totalling $86 million.The
present worth of costs for this system is $0.9 billion.
4.1 NORTH SLOPE TO FAIRBANKS NATURAL GAS PIPELINE
The design of the gas pipeline and the gas conditioning facilities
proceeded on the basis of preliminary gas demand calculations (detailed
in Appendix A).Subsequent refinement of total peak demand for the
Fairbanks scenario based on domestic gas distribution and electric usage
(detailed in Appendix E and Appendix B respectively)did not require
design changes in the pipeline but resulted in small differences in gas
demands in the sections that follow.The pipeline gas demands are as
follows:
2648B
Pipeline Design
(Prel iminary Demand)
Power Generation
Annual Average Demand
Daily Peak Demand
Resi denti al /Commerci al
Annual Average Demand
Daily Peak Demand
Total s
Annual Average Demand
Daily Peak Demand
4-2
Medium Load Forecast
(MMSCFD)
186
307
27
76
213
383
.-
The refined values on which the Fairbanks gas distribution system and
the electric generating unit additions depend are as follows:
Utility Systems Design
(Refined Demand)
Power Generation
Peak Daily Demand
Residential/Commercial
Pe ak Da i1y Demand
Total s
Peak Daily Demand
Medium Load Forecast
(MMSCFD)
271
63
334
"""
,~
The refined gas demand is about 50 MMSCFD less than the preliminary
value,an amount insufficient to necessitate pipeline design changes.
4.1.1 Gas Conditioning Plant
Gas to be transmitted through the pipeline will first be conditioned on
the North Slope.The conditioning facility will receive the gas from
the production fields,treat it,and compress it to 1260 psig and a
temperature of 25 to 30°F.Initial design delivery volume will be 230
MMSCFD;however,the plant will be capable of expansion to 407 MMSCFD
as future demand increases.These values are based on total Fairbanks
gas demand,compressor station requirements and a pipeline avai'lability
of 96.5 percent.The gas delivery and quality specifications are
presented in Table 4-1.
The process assumed for carbon dioxide removal is Allied Chemical's
SELEXOL PhYsical solvent process,the same process selected for use
with ANGTS.A mechanical refrigeration process will control
hydrocarbon dewpoint.Water dewpoint control will be accomplished in
the dehYdration equipment located in the existing Prudhoe Bay Unit
gas/crude oil separation sites called Gathering Centers and Flow
Stations.The hydrogen sulfide content of the feed gas is very low.
It was therefore assumed that no process equipment will be requi red for
~ither water dewpoint control or hydrogen sulfide removal.
26488
4-3
TABLE 4-1
GAS DELIVERY AND QUALITY SPECIFICATIONS
"'""
-
2648B
Parameter
Initial Delivery Volume
Ultimate Delivery Volume
Delivery Pressure
Delivery Temperature
Carbon Dioxide Content (max.)
Hydrogen Sulfide Content (max.)
~drocarbon Dewpoint (max.)
Water Dewpoint (max.)
4-4
Specifications
230 MMSCFD
407 MMSCFD
1260 psig
25-30°F
2.0 volume %
1.a grai nil 00 SCF
-10°F @ 1000 psia
-25°F @ 1000 psia
.....
A simplified process flow diagram illustrates the basic process flow of
the conditioning facilities (Figure 4-1).Two trains will be
installed,one for continuous operation and the other as a spare.Feed
gas,originating from the gas/crude separators,will be compressed in
the Gathering Centers and Flow Stations and flow to the inlet
separation unit.The inlet gas streams will be metered,and any solids
or free liquids in the gas will be removed at this point.The feed gas
will flow first to the natural gas liquids (NGL)extraction section for
hYdrocarbon dewpoint control.The gas will then flow to the SELEXOL
section where the carbon dioxide is removed.The conditioned gas will
then go to the gas compressors where it will be boosted to pipeline
pressure,then refrigerated for transmission.SELEXOL solvent
characteristically absorbs,along with the carbon dioxide,a
significant quantity of hydrocarbons,particularly the heavier
hYdrocarbons.During the regeneration of the SELEXOL solvent,both the
carbon dioxide and hydrocarbons are flashed from the solvent,producing
a low Btu gas.The gas will be utilized within the facility to offset
some of the energy requirements.
The hydrocarbon 1 iquids from the NGL Extraction and SELEXOL flash gas
will be separated in the fractionation unit into propane,butanes,and
pentanes-plus products to facilitate disposal.Some propane will be
used for heating value control of certain fuel streams.The remaining
propane will be injected into the pipeline gas.The butanes will be
either injected into the pipeline gas up to hydrocarbon dewpoint limits
or into the crude oil delivered to the Trans Alaskan Pipeline System
(TAPS)as is presently accomplished at the existing central compression
facility for gas reinjection.The pentanes-plus will be injected into
the same crude oil stream.
The facilities will require approximately 175,000 total installed
horsepower i ncl udi ng motors,power recovery units and gas turbines.,....
The bulk of thi s horsepower will be developed by 9 operating gas
turbines with 6 spare gas turbines.The major auxiliary systems will
include refrigeration,offsite and general utilities,and power
generation facilities.
26488
4-5
1 j 1 1 J J )1 J 1 J i J 1 "9 ]J 1
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I • '•••J ~"::'
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..-l::'..i
I •I:__.~';'I u •I ~~~
ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEASIBILITY STUDY
GAS CONDITIONING FACILITY
PIG""!4-1
EBASCO SERVICES INCORPORATED
-
.....
The remoteness and severe environmental conditions at the North Slope
impose limitations on both the process and mechanical design of the
facilities.All equipment,will therefore be housed in totally
enclosed modules.Modules,with contained equipment,will be
fabricated prior to shipment to the North Slope.They will be
sea-l i fted to the North 51 ope by ocean-goi ng barges.At Prudhoe Bay
they will be offloaded by crawler transporters or rubber-tired vehicles
and moved to their pile supports on graveled sites.
A critical timing factor in any construction program at Prudhoe Bay is
the limited time period during which the sea lanes are passable.Major
plant components can only be delivered via ocean-going barges during
the short (4-6 weeks)peri od each year when the sea 1 anes are not
blocked by ice.Failure to deliver any critical major component during
the scheduled period could effectively delay full-capacity startup by
one full year.
4.1.2 Pi pel ine
4.1.2.1 Pipeline and Route
Gas to be transported will be provided to the pipeline from the gas
conditioning plant.Pipeline quality gas will be a hYdrocarbon mixture
with approximately 88 percent methane,and a gross higher heating value
of approximately 1100 Btu/SCF.The pipeline will be designed and
operated to maintai n the soil around the buri ed sections of the
pipeline in a frozen state.The operating temperature of the gas in the
pipeline will be between O°F and 32°F under normal conditions.
However,during transient periods,the gas in the line may exceed 32°F
or may go down to as low as _5°F for short periods of time.
The proposed pipeline route originates in the Prudhoe Bay area in
northern Alaska (refer to Appendix C).The pipeline will connect to
the gas conditioning plant at the metering station,designated
Mi 1epost O.The pi pel i ne route,whi ch assumes the ANGTS ri ght-of-way,
26488
4-7
i,~
-
follows TAPS in a southerly direction to about Milepost 274 near
Prospect Creek.The pipeline rQute then follows TAPS in a
southeasterly direction to about Milepost 480.the assumed location of
the power plant metering station.A tap will be provided at Milepost
455 near Fox to supply gas to Fairbanks for residential and commercial
uses.
The pipeline will cross 15 major streams requ1rlng special construction
considerations.such as heavy wall pipe.continuous concrete coating or
set-on concrete weights.At the Yukon River an existing aerial
crossing will be used.
There will be 20 uncased road crossings.27 road crossings with 28 inch
casings.and 8 road crossings with 36 inch casings.The pipeline will
cross TAPS at 21 locations.the TAPS fuel gas line at 13 locations.and
other pipelines at 3 locations.
The basic assumption that this pipeline will follow the ANGTS
right-of-way is a major one.Pipeline design and subsequently cost
could be greatly affected if this right-of-way could not be used.
Significant areas of concern would include the narrow Atigun Pass area
and the Yukon River crossing.
4.1.2.2 Pipeline Design
The pipeline design pressure will be 1260 psig.based on current proven
technology for resistance to crack propogation at low temperatures.
The pipeline has been designed for the daily peak flow required to
satisfy the gas demand associated with the medium forecast assuming a
pipeline availability of 96.5 percent.The following flowrates were
used for the hYdraulic design of the pipeline:
26488
Annual Average Flow (MMSCFD)
Dai ly Peak Fl ow(MMSCFD)
4-8
213/0.965 =220
383/0.965 =397
....
-
Initial annual average daily capacity of the pipeline will be
127 MMSCFD with a peak daily load of 227 MMSCFD during extreme cold
weather periods.
The peak daily flowrate will require a pipeline outside diameter of 22
inches.The pipe shall be API 5LX or API 5LS Grade X70 with a minimum
wall thickness of 0.275 inches for the majority of the length.At road
crossings,bridges,and within public road right-of-ways,the minimum
wall thickness will be 0.330 inches.These thicknesses are based on
the entire pipeline being located in a Class 1 location as defined in
CFR 49,Part 192 •.
The peak daily flowrate requires 10 compressor stations of
approximately 3400 HP each.The average daily flowrate will require
only 3 compressor stations,Stations 2,4 and 7.The compressor
stations are at the locations selected by ANGTS and use the same
numbering system.The delivery pressure to the power plant will be
1038 psig.Figure 4-2 summarizes this flowrate condition.Compressor
F'"station fuel consumption will be approximately 1 MMSCFD per operating
station.
\A total of 28 mainline block valve assemblies will be provided at a
nominal spacing of 20 miles including the initial compressor sites
where the mainline valves will be installed in the station bypass
loop.Seven of the 28 block valves will be installed at the additional
station sites to facilitate system expansion.Pig launchers and
receivers will be installed at the compressor and metering stations.
I.,
-
.....
The pipe will be installed in a buried mode,using the proposed ANGTS
construction techniques.Pipe ditches wi.ll be selected from several
basic types,based on site-specific conditions.Special ditch
configurations will be required to provide for the mitigation of frost
heave effects in areas having frost-susceptible soils.
2648B
4-9
-J 1 }J ]J 1 J ))1 J !
I.i
r,;,;].......5"LoS.I ."c.1'5.C.~".f,.~.C.~5"5:9 ~.(;S...,'!.7 ....."'5.c.o.:t So !!II.2-~47.'r;;,;
CoS.5.e.'!.~V Go~~I)
~c:"\A ..0
11/'"11 ..
Z SIII•~tio4\'1 )~Ill"i~!lot:
"e!h
ill!~{1/."II.~.t-0&"t ~£
80 MM sc:.r-/b Ih~~i )'
TOTAL 480 MILES.22-0.0.PIPELINE.WALL THICKNESS •0-275 INCH MINIMUM
STATION DESIGNATION II."C•••I C•••I C....C.,.4 C.,••C••••C.,.,C.,••C."•C•••10 .....
I'IIUDHOlt Mr POWltIl I'UIIT
MILEPOST (MILES)0.0 44.5"~o.1 ,\3.7 141.3 17'.1 2.35:0 27.3."320.7 31'0..,....32..1 4?o.o
nEVATlON (FEET)2.1 .3'-2-S2.S"1'5"2.S":!505"O 3/S'1f 12.2.0 1'31S 17:30 .,.,0 1$2.0 S"<:JO•STATION INLET VOLUME (MMSCF/D)3"M ..3,g 3'~0 407 407 4o,"4Q5"'404-04b.3 402-40/400~
;!TOTAL FUEL (MMSCF 10)-I 1 /I 1 1 /1 ,/-tit
STATION ounn VOLUME (MMSCFID)407 40(;,405'404 403 40'2.401 ....00 3."3"111 3"7 311
ITATION SUCTION PRESSURE (PSlO)1'2.,"0 10+7 1043 1057 10'31 10'3 I 1'2.4 10'S-IOg1 102.,'71 l03!
STATION DISCHARGE mSSURE (PSlO)/2'0 12-4-!S /24S"12.45 /'2.30 I~30 1'2...'0 12'0 1230 /230 II-t5 -
a COMPRESSOR SUCTION PRESSURE (PSIO)-1031 10-+7 /041 lOIS"1047 lIo'R 1071 1023 1012-'55 -0
it COMPRESSOR DISCHARGE PR£SSURE (PSllJ)/'l.5""'''~/2.5"12 ......12:44 127.....1::2.74-1244 1244 liS.,-tit -'"K COMPRESSION "ATIO 1.200 I.:2.0'1.2.22 1.11'1.148 1.171 ,.2/3 I.~2'/.2/0 -..-I.2./.,:I
0 ffORSEPOWU "EQUII'ED 2'00 2750 32.00 3250 3 ....00 -u -3 ....00 3/5'0 .32.00 30400 'Z,!,oo
ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEASIBILITY STUDY
HYDRAULIC SUr1MARY
t1EDIUf1 FORECAST
PEAK DAILY FLOW
FIGURE 4·-2
EBASCO SERVICES INCORPORATED
....
.-"
i
-
-
Pipeline corrosion control will be provided by a combination of
external coating and a cathodic ,protection system that will be
compatible with the sacrificial zinc anode system used on the adjacent
TAPS pipeline.The pipeline will be hydrostatically tested to 1.25
times the maximum allowable operating pressure •
4.1.3 Compressor and Metering Stations
Two meteri ng stations will be provi ded.One will measure the quantity
of gas supplied to the pipeline from the gas conditioning plant at the
North Slope,and the other will measure the gas delivered to the power
pl ant just south of Fa i rbanks.Detai 1s of the compressor and meteri ng
stations design are provided in the Figures 4-3 and 4-4.
Each compressor station site will require about 10 acres,and the
meteri ng stati ons about 1.5 acres of 1and.Compressor stati ons wi 11
include buildings for the compressors,refrigeration equipment,
utilities and control room,flammable liquids storage,warm storage and
garage,a gas scrubber unit,living quarters and interconnecting
hallways.Additional living quarters,office,and shop and warehouse
building will be included at compressor stations 2 and 7.
Two refrigeration units will be provided at every compressor station to
maintain the pipeline gas temperature.Gas heaters will be prOVided at
compressor stations No.2 and No.4 to assure that gas temperatures
will be maintained above the hydrocarbon dewpoint of the mixture under
all operating conditions.Pipeline gas will be used to power the
drivers for the gas compressors,refrigerant compressors and electric
generators.Compressor station and metering station design and
equipment are summarized in Tables 4-2 through 4~10.
4.1.4 Supervisory Control System
A supervisory control system will be provided to operate the pipeline
system,perform related system balancing,and coordinate functions with
the gas conditioning plant at the North Slope and the Fairbanks power
plant.
26488
4-11
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-
.-
ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEASIBflITY STUDY
-
TYPICAL Cm1PRESSOR STATION LAYOUT
FIGURE 4-3
EBASCO SERVfCES INCORPORATED
,.,..,
'"
Q
B~OWDOWN")
ClRVM c:::P
°VEtJ'r
S-rAl:.K.
ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEASIBILITY STUDY
TYPICAL t1ETERING STATION LAYOUT
FIGURE 4-4
EBASCO SERVICES INCORPORATED
i~
-
TABLE 4-2
PIPE DETAILS
Major piping -1260 psig design pressure
a.22 11 0.0.x 0.406 11 wall API 5LX,GR.X70 pipe
b.o 18 11 0.0.X 0.750 11 wall ASTM A333,GR.6 pipe
c.16 11 0.0;x 0.656 1l wall ASTM A333,GR.6 pipe
d.12 11 XS ASTM A333,GR.6 pipe
e.1011 XS ASTM A333,GR.6 pi pe
f.811 STD.WT.ASTM A333,GR.6 pipe
NOTE:API 5LX piping to have additional specifications for
-50°F Charpy Impact requirements and chemical
requirements for improved we1dabi1ity.
2648B
4-14
--
-
TABLE 4-3
CIVIL DESIGN DETAILS
a.All buildings and heated components will be elevated on steel
pile foundations above a gravel pad to allow free air
circulation under the structures.The pile embedment will be
adequate to prevent frost jacking of the structures.
Non-heated facilities will be supported by a granular fill and
sand pad.
Snow loads will be 60 psf
Earthquake design will be Zone 3
Wind loads will be:30 psf
40 psf
50 psf
60 psf
30'height
30 1 -50 1 height
50 1 -100'height
100 1 height
.-
--
!~
e.Ambient temperature range -70°F to +80°F
f.Structural steel -inside heated structures~will use nonnal
steel material s.Outside heatedstructures~will use suitable
low temperature steels.
g.The diesel fuel storage tank will be placed over an impenneable
liner covering the entire diked area.
2648B
4-15
-
.-,
TABLE 4-4
BUILDING DETAILS
a.All buil di ngs wi 11 be pre-engineered i nsul ated-pane(metal
structures,suitable for their intended use •
b.Buildings suitable for truck transportation through size or
modularization will be prefabricated.
c.Hazardous materials storage buildings will be mechanically
ventilated.Ventilation rates will be four air changes per
hour for nonnal ventilation and 15 air changes per hour for
emergency conditions.
2648B
4-16
,~
.-
2648B
TABLE 4-5
COMPRESSOR AND GAS SCRUBBER DETAILS
Main Compressors - 1 each per compressor station
a.Compressor -1280 psig min.design pressure
1.23 pressure ratio
6000 ft.adiabatic head
2750 ACFM
b.Gas Turbine Driver -3800 ISO Horsepower
gas fueled
c.Typical Equipment -Solar Centaur Gas Turbine
Natural Gas Compressor Set with a C-304 Single Stage
Compressor:>or equal.
Gas Scrubber -(l )each per station
·a.Designed to remove 99.5%of all solid and liquid particles
1 micron and larger..
b.Design flowrates will range from 130 to 400 MMSCF/D.
c.Typical Equipment -Peeo Robinson filter and liquid-gas
separator:>Model 75H-56-FG372:>or equal •
4-17
-
-
-
....,
.....
I
-
TABLE 4-6
REFRIGERATION SYSTEM AND GAS HEATER DETAILS
Refrigeration System
a.Refrigeration system will be a compression/expansion type using
Freon gas and a gas turbine driver for the refrigerant
compressors.
b.Chillers will be shell and tube with natural gas in the tubes
at 1280 psig and Freon in the shell.
c.Condensers will be air cooled with multiple electric driven
fans.
d.Required capacity will be 1650 tons (2200 HP).
e.The system will be comprised of two parallel 50t refrigeration
trains to meet the total required capacity.
f.Typical Equipment -Two (2)825 ton (1100 HP)refrigeration
trains using Solar Saturn Gas Turbine Compressor Sets,or equal •
Gas Heater -One (1)each at Compressor Stations 2 and 4 only
a.Designed to add 5,000,000 Btu/hr.to heat the pipeline gas
during low flow winter conditions .
b.Equipment will be a gas fired heater and utilize a water/glycol
solution to heat the gas in a shell and tube heat exchanger.
26488
4-18
-
....
-
-
-
TABLE 4-7
COMPRESSOR STATION
ELECTRICAL SYSTEM AND CONTROL SYSTEM DETAILS
Electrical System
a.Each station will be self-sufficient in electric power with
its own power generation and distribution system.
b.Power will be 480 V.,3 phase,60 Hz.
c.Main generators wi 11 be two (2)800 KW conti nuous duty
dual-fueled gas turbine driven generator sets,one will
normally supply the station load and one will be standby.
d.Emergency (l ifeline)generator will be one (l)200 KW diesel
engine driven generator connected to the essential services
bus.
e.The emergency generator will be located in the warm storage
building or another location remote from the main generators
in the utilities building.
f.Typical Equipment:
Main generators -Solar Saturn GSC-1200,or equivalent
Emergency generator -Caterpiller 3406 TA,or equivalent
Control System
a.Each station will have a control system designed for
completely remote and unattended operation.
b.The station central Control Unit (CCU)will be linked by
communications to the Operations Control Center (OCC).
c.Each individual piece of station equipment will have its
individual control system which in turn will be controlled by
the CCU which is the master controller.
d.The OCC input to the CCU will primarily be start/stop commands
and setpoint changes.
e.The acc will have sufficient information transmitted to it to
allow for full compressor station control.
2648B
4-19
~,
-
-
TABLE 4-8
MISCELLANEOUS COMPRESSOR STATION SYSTEMS'DETAILS
a.Blowdown and Flare System will be sized for 100,000 lb/hr.of
saturated light hydrocarbon gases and liquid storage capacity
of 10,000 gallons.
b.Nitrogen Purge System -for purging.
c.Instrument and Utility Air System -Instrument air to be clean
and dry for operating pneumatic control system components.
Utility air for power tools and maintenance.
d.Fuel Gas Conditioning -Gas for station fuel requirements will
be filtered,heated,reduced in pressure,and distributed at
500 psig.
e.Diesel Fuel - A diesel fuel storage and back-up fuel system
will be provided for electric power generation and heating.
The tank size will be 40,000 gallons to provi de 14 days of
capacity.
f.Fire Protection -Station fire protection will be provided by
a Halon 1301 extinguishing system with a water/foam back-up
system.
g.Water System - A single 40,000 gallon water tank will provide
a source of water for potabl e uses as well as for the back-up
water/foam fire system.The fi re pump will be di esel dri ven.
The potable water will be filtered,chlorinated,and
distributed.
h.Sewage System -Sewage will be collected by a vacuum
collection system.Final disposal will be through a septic
system or a lagoon as site conditions warrant.Lagoon
disposal will require secondary treatment and chlorination.
i.Heating System -The station will be heated by a water/glycol
system utilizing waste heat from the station turbine
generators.A combustion boiler unit will be provided as
back-up to the waste heat system.
j.Cathodic Protection - A cathodic protection system will be
provided to protect all buried piping,tank bottoms,and other
structures in contact with the soil.The station will be
electrically insulated by isolation flanges where the pipeline
enters and leaves the compressor station property.
2648B
4-20
-
,-
-.
-
.-
,..,.
,
TABLE 4-9
METERS AND METERING STATION ELECTRICAL AND CONTROL SYSTEMS DETAILS
Meters
a.Each metering station will have 3 parallel meters with
provisions for future addition of a fourth meter.
b.Meters will be concentric orifice plate with differential
pressure transmitters.
c.Meter runs will be 12 inch diameter by 3D'long.
Electrical System
a.Both metering stations will be powered by an outside
commercial power source.
b.A 50 kW diesel-powered back-up generator will automatically
come on 1ine during a power failure.
Control System
a.Designed for remote and unattended operation.
b.Gas flow will be computed by a microprocessor-based flow
computer with 100%redundancy.
c.Tne flow computer will be linked to the OCC by
telecommunications •
2648B
4-21
---_._------~--~-------
r
-~,
-
..-
.....
-
TABLE 4-10
MISCELLANEOUS METERING STATION SYSTEMS·DETAILS
a.Blowdown drum and vent stack system
b.Ni trogen purge system
c.Diesel Fuel - A diesel fuel storage system will be provided for
electric power generation.
d.Fire Protection -Fire protection will be provided by a Halon
1301 extinguishing system with a water/foam back-up system.
e.Heating System -Heating and ventilating will be by means of
redundant gas-fired furnaces and warm air duct systems.
f.Cathodic Protection - A cathodic protection system will be
provided to protect all buried piping~tank bottoms~and other
structures in contact with the soil.The station will be
electrically isolated by isolation flanges where the pipeline
enters and leaves the compressor station property •
2648B
4-22
-
.....
,~
r~
The supervisory control system master station will be located near the
Fairbanks power plant at the operations control center (OCC).A
communication system will provide the voice and data intertie to each
compressor and metering station from the acC.Each station will include
a control system that will interface through the communication link to
the acC.
The OCC in Fairbanks will include the dispatcher console,which will
provide the monitoring and control equipment necessary for centralized
operation of the pipeline.
4.1.5 Communications System
The communications system will include voice and data transmission
systems,the mobil e radio system,and record communicati ons.A basi c
communication system will be installed during the construction phase to
provide voice and data links among the pipeline and compressor station
camps,and the Fairbanks construction headquarters.
Mobile radio equipment will be provided to pennit communication by field
construction teams through a network of repeater stations to the camps,
stations and other facilities.This basic communication system will
later be modified to provide the operational communications system.This
operati ona 1 system wi 11 support the supervi sory.contro1 system.Data
communications will also be prOVided.
4.1.6 Operations and Maintenance Facilities
Operations and maintenance {O&M}facilities will be located at three
sites along the pipeline:Compressor Stations 2 and 7,and the Fairbanks
operations headquarters.Each O&M facility will include the following:
n)Warehouse for stori ng project spare parts inventory.
{2}Maintenance shop,including maintenance equipment.
{3}District office.
(4)Living quarters for the O&M personnel.
26488
4-23
-The Fairbanks operations headquarters near the power plant will also
house the OCC,the related supervisory control equipment,required power
supplies and the communications system equipment.
Stations 2 and 7 will serve as shop and warehouse with both 1 iving
quarters and maintenance facilities.The other stations will have small·
living quarters attached.It is anticipated that a staff of 5-6 will
serve at each compressor station except stations 2 and 7,which will have
a total of 16 each,including 6 maintenance personnel.This would then
require a total staff of 80 for the medium load forecast peak demand (10
stations).
4.L 7 Co nstructi on and Si te Support Services
Temporary facilities will include those facilities required to support
the construction phase activities.These facilities will include the
Fairbanks construction headquarters,the pipeline and compressor station
construction camps,airfields,access roads,material (borrow)sites and
disposal sites.
Thirteen pipeline construction camps will be provided along the route,
i nc1udi ng one located at the Fairbanks construction headquarters site.
These camps will be capable of accommodating between 250 to 1,300
persons,depending on location and planned use.
The camps,once completed,will be turned over to contractors for
operation.The twelve camps along the pipeline will be renovated
generally in p1 ace using equipment and modules obtained mostly from the
existing TAPS camps.Three compressor station construction camps will be
prOVided by relocating and renovating equipment and modules available
from eight existing TAPS pump station camps.
Airfields will consist of certain existing commercial airfields,as well
as renovated private airfields preViously built in support of TAPS."
Material (borrow)sites are available along the pipeline route to provide
2648B
4-24
-
construction materials,as well as areas to dispose of construction
spoil.Maximum haul distances should be kept under 5 miles.
A pipe yard at Fairbanks will be provided to receive mainline pipe,
store,externally coat,double-joint (weld)and insulate pipe as
required.Access roads will be provided as needed to allow access to
stations,borrow sites,pipeline spreads and related facilities.
4.2 POWER PLANT
The Report on System Planning Studies (Appendix B)concluded that
combined cycle power plants are the most technically feasible and
economical choice for satifying demand when generating electrical power
at a Fairbanks site.The individual combined cycle plants will consist
of two gas turbines,each with a heat recovery steam generator and one
steam turbine for a total of three turbine-generator sets.
4.2.1 General
The Fairbanks site will contain all required generating units,
construction and mai ntenance facil iti es,various auxili ary and support
systems,a central control f~cili ty and switchyards.Thi s power
generation scenario calls for five 242 MW combined cycle and two 86 MW
simple cycle units to satisfy the demand for energy in the year 2010.
The first unit,a simple cycle gas turbine,is required in 1993 and in
subsequent years either gas turbines or steam turbines are added.
Incremental and total required new generation capacity for this scenario
are summarized in Table 4-11.
A single combined cycle unit will require an area with outside dimensions
of 300 feet by 440 feet.The arrangement of the three turbine-generator
sets,the air cooled condenser and auxiliary equipment is shown in
Figures 4-5 and 4-6.The site plan shown in Figure 4-7 illustrates the
planned installation method (side by side)for up to six units with
switchYards.This arrangement will require a total area of approximately
150 acres.
2648B
4-25
-
TABLE 4-11
NEW CAPACITY ADDITIONS AND FUEL REQU IREMENTS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST
~New Capacity (MW)Gas Requi red!!
Year (Increment/Total)(MMSCF)
.....
1990 0/0 O.
1991 0/0 O.
1992 0/0 O.
1993 86/86 6,265.8
~1994 0/86 6,265.8
1995 86/172 12,531.6
f 1996 70/242 12,633.1~,
1997 172/414 25,132.7
1998 70/484 25,202.9
1999 0/484 25,202.9
2000 86/570 31,551.3
2001 0/570 31,467.3
2002 156/726 37,804.3
2003 0/726 37,804.3
2004 86/812 44,188.1
2005 156/968 45,809.0
2006 86/1050 49,535.1
2007 86/1140 53,145.7
2008 70/1210 52,292.0
2009 86/1296 55,892.6
2010 86/1382 59,424.8
....
2648B
Values as calculated are shown for reproducibility only,and
do not imply accuracy beyond the 100 MMSCF level •
4-26
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NOATH SLOPE GAS
FEASIBILITY STUDY
COMBiNED CYCLE PLANT
GENERAL ARRANGEMENT
ElEVATIONS
ALASkA POWER AUTHORITY
:tI=m..,
-....~-<~~~.........
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10 LJ:loI>P CIENTllfto ALASKA POWER AUTHORITY
NORTH SLOPE GAS
FEASIBILITY STUDY
COMBINED CYCLE PLANT
SITE PLAN
FAIRBANKS AND KENAI
FIGURE 4-7
l-l ~.-I.-t .-4 -t._t.-I._t--"t>_t-t Lt EBASCO SERVICES INCORPORATED
-t-t.·-f--t..-t ·
-
.-
The functional parts of the plant will be similar to those described in
Section 2.0 for the gas turbine portion of the plant.The steam cycle
will require the addition of heat recovery steam generators,steam and
auxiliary system piping,a steam turbine generator,condenser,condensate
polishing,water quality control systems,and an increase in the quantity
of water used.
4.2.2 Combustion Turbine Equipment
All combustion turbine equipment will be identical to that described in
Section 2.1.
4.2.3 Steam Plant
The heat recovery steam generators (HRSG)are considered part of the
steam plant although phYsically the steam generators will be housed
together with the gas turbines in a large common building .
Each heat recovery steam generator package,one at each gas turbine
exhaust,will include the steam generator complete with ductwork from the
combustion turbine to the steam generator,a bypass damper and bypass
stack,and a steam generator exhaust stack.The steam generators will
have a steam outlet pressure of 850 psig at 950°F.Each steam generator
is designed to produce one half of the plant1s nonnal flow for steam when
supplied with feedwater at a temperature of 250°F.The heat recovery
steam generators are designed for continuous operation.All steam
generator controls will be located in a common area in the central
control room.
During start-up and other load conditions,the bypass damper may be
operated to provi de operati ona 1 fl exi bi 1i ty.By openi ng the bypass
damper and closing the louvered dampers,the combustion turbine exhaust
is routed to the stack and does not reach the steam generator.Desi gn
parameters for the heat recovery steam generators are shown in Table
4-12.The flow diagram and anticipated heat balance for a single
combined cycle unit is presented in Figure 4-8.
26488
4-30
-Type:
TABLE 4-12
HEAT RECOVERY STEAM GENERATOR DESIGN PARAMETERS
(Two Required Per Unit)
Watertube,forced circulation
Performance:(Each Steam Generator)
Main Steam
Outlet Condition
Quantity
850 psi g,950°F
250,400 1bs/hr
-
.....
......
-
Steam production under normal operation will be achieved with an
exhaust gas flow through the boiler of 2,286,000 1bs/hr at 970°F.
Feedwater will be supplied to the HRSG at 250°F from the feedwater
heater.
Heat Recovery Steam Generator Features
Feedwater Heater
Economizer
Evaporator Section with Steam Drum
Superheater Section
Economizer
Evaporator Secti on wi th Steam Drum
Exhaust Gas Bypass Dampers with Separate Stack
2648B
4-31
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toIIClJtTU"L ONLY
NOT liIU"""NTEED
-.......,.....
--_.._.....
.tm.n;
COMBINED CYCLE PLANT
FLOW DIAGRAM AND
HEAT BALANCE
NORTH SLOPE GAS
FEASIBILITY STUDY
ALASKA POWER AUTHORITY
~
..cl/.....''''''ft1Na""...."1':1;".IlIIlfT ....,.....,-
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IIAICO RAVlCES N:OAPOftATED
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The generator is rated 72 MW The unit auxiliary transformer is a
three winding 15 MVA,13.8/4.16~4.16 kV.The two secondary windings
supply 4.16 kV buses 3A and 3B.The step-up transformer is rated 50
MVA,18/138 kV.
The main steam produced in the heat recovery steam generators will be
conveyed to a common turbine generator set.The turbine generator wi 11
be a tandem compound,multistage condensing unit,mounted on a pedestal
with a top exhaust going to the air cooled condenser.Design
parameters for the turbine generator are shown on Table 4-13.The
turbi ne generator set wi 11 be furni shed complete wi th 1ubri cati ng oi 1
and electrohYdraulic control systems as well as the gland seal system,
and the generator cooling and sealing equipment.
In addition to the combustion generators,steam generators and steam
turbi ne,the buil di ng wi 11 also contai n the feedwater pumps,condensate
pumps,vacuum pumps,deaerator,instrument and service air compressors,
motor control centers,control room,and diesel generator (see Figure
4-5).The diesel generator will be sized for black start-up service.
Heat will be rejected from the steam turbine cycle at the outside
mounted air-cooled condenser where air flowing across cooling fins
absorbs heat from the exhaust system.The condensate from the
condenser will then flow to the condensate storage tank where it will
be pumped back into the cycle.
Fuel requirements for this scenario will start at approximately 6.27
BCFY in 1993,when the first gas turbine starts delivering power,and
increase to 59.43 BCFY in the year 2010.The maximum anticipated gas
consumption rate,in the year 2010,with 1382 MW of capacity in
operation,is 1.88 x 10 5 SCFM.Detailed annual gas use figures are
presented in Table 4-11.
2648B
4-33
r TABLE 4-13
STEAM TURBINE GENERATOR UNIT DESIGN PARAMETERS
(One Required Per Unit)
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST
Multistage,straight condensing,top exhaust
~drogen-cooled unit rated 72 MW at 13.8 kV
with 30 psig hydrogen pressure at lOGe
Common base mounted with direct-drive
couplings.Accessories include multiple
inlet control valves,electric hydraulic
control system,lUbricating oil system with
all pumps and heat exchangers for cooling
water hOOK-UP,gland steam system and
generator cooling.Excitation compartment
complete with static excitation equipment •.
Switchgear compartment complete with
generator breaker potential transformers.
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Turbine Type:
Generator Type:
Perfonnance:
Steam Turbine Generator
Features:
2648B
Base Rating
Steam Inlet Pressure
Steam Inlet Temperature
Exhaust Pressure
Exhaust Temperature
Speed
72 MW
850 psig
950°F
211 to 411 Hg
108°F
3600 RPM
4-34
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4.2.4 Substation
The circuit diagram of the powerplant substation is shown in
Figure 4-9.It is quite similar to the North Slope substation
(Figure 2-3).Two generators will be connected to the two primary
windings of the 250 MVA 13.8/138 kV transfonners,and the last
generator to a 125 MVA two wi nding transfonner.The bus arrangement
will use a breaker and a half scheme unless reliability considerations
mandate otherwise.Two 750 MVA 138/345 kV transfonmers will supply
each of the transmission line circuits.Each of the transmission lines
will have a circuit breaker.On the line side of the circuit breakers
are the series capacitors and the shunt reactors.This arrangement has
the advantage of being flexible as far as operation is concerned and
can be expanded easily.
4.2.5 Other Systems
In addition to the potable and service water system described in
Section 2.1,thi s pl ant will requi re make-up water for the steam
cycle.To purify the make-up water a demineralizing system will be
requi red.
SlOWdown from the HRSG's and waste from the demineralizer and the
condensate polisher represent additional waste handling capacity
re'quirements over and above that previously discussed (Section 2.1).
These waste streams will require treatment,in accordance with
regulation,prior to discharge.
Other systems such as fire protection or lUbricating oil will not
change in scope or capacity to any significant degree from those
presented in Section 2.1.
26488
4-35
~~'--'--j '-j "------4 ~~~~~-----;------,~------,~
22 (}Ci 22 22 22 22 22 22220MVA
TYPICAL
500 MIA
TYPICAL
If •__...,.,,....,
~I
TO ANCHORAGE
LoCAL.
.345 kV
~n
LOCAL.
2110 MVA
ALASkA POWER AUTHORITY
NORTH .LOPE QAS
FEASIBILITY STUDY
FAIRBANKS POWER GENERATION
MEDIUM LOAD FORECAST
SUBSTATION ONE LINE SCHEMATIC
'..URE 4-1
(BASCO IERVtCES NCORPOAATED
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4.2.6 Construction and Site Support Services
The construction of this power plant in the·Fairbanks area will require
the following services:
1.Access Roads
2.Construction Water Supply
3.Construction Power Supply
All new roads will be of similar design to existing public roads in the
Railbelt.The roads will be paved,and will meet all code design
requirements for the maximum loads expected.
A complete water supply similar to that described in Section 2.1 will be
provi ded,except the source of water will be wells.The constructi on
power supply will be a 12.47 kV line run from existing facilities.
Since a permanent construction force will be utilized through the period
of the study,it is assumed that the local area can supply living
accommodations for the workforce.The number of workers necessary for
construction of the power station will vary over the total period of the
project from a low of 50 to ~hi gh of approximately 200.Constructi on
facilities required are:utility services;temporary construction office;
temporary and permanent access roads;temporary enclosed and open laydown
storage facilities;temporary office and shop spaces for various
subcontractors;settling basins to collect construction area storm
runoff;and permanent perimeter fencing and security facilities.
4.2.7 Operation and Maintenance
Plant Life
Each unit will have a 30 year life expectancy,which is based on the life
of the gas turbine units.It is expected that the gas turbine units will
be overhauled a number of times throughout the life of the units during
scheduled or unscheduled outages.
2648B
4-37
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Heat Rate of Units
The facility's heat rate will va~~depending on the number of gas
turbines and heat recovery units operating at a given time.Ideally,
with only combined cycle units in operation~a heat rate of 8290
Btu/kWh (HHV~ambient conditions)can be realized.
Scheduled and Forced Outage Rate
It is expected that the forced outage rate will be about 8 percent.
Operational experience on other plants indicates higher forced outages
in the first few years~but this is attributed to operational
adjustments required for a new plant.It is expected that a slight
increase in forced outages will occur as the plant ages.Scheduled
outages for annual maintenance and periodic overhaul are expected to be
approximately 5 percent.
Operating Workforce
The combined cycle power plant will require a continuously increasing
staff over the study period.The staff will start at approximately 10
on-duty personnel when the first gas turbine begins operation and will
increase to approximately 80 on-duty personnel in the year 2010.
4.2.8 Site Opportunities and Constraints
Fairbanks represents the nearest location to which North Slope gas can
be transported to and have the resulting generation of electrical
energy be fed directly into an existing portion of the Railbelt
electric transmission network.Transportation of heavy equipment to
the site does not represent technical problems;however~the location
will require expensive overland transport from the port faciliti~s at
Anchorage.
2648B
4-38
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4.3 TRANSMISSION SYSTEM
The power to be transmitted from Fairbanks to Anchorage equals the power
generated less the Fairbanks area load.This amount is the same as the
North Slope generation scenario,except for the line losses between the
North Slope an-cl Fairbanks,which are not significant when compared to the
power generated.Therefore,the conditions for the Fairbanks to
Anchorage transmission line are almost exactly identical for both cases
and consist of two new 345 kV lines,and an upgrade of the
Willow-Anchorage and Healy-Fairbanks segments of the Intertie from 138 kV
to 345 kV (Refer to Section 2.2).
4.4 FAIRBANKS GAS DISTRIBUTION SYSTEM
4.4.1 Fairbanks Residential/Commercial Gas Demand Forecasts
The following paragraphs are a summary of the study performed by Alaska
Economics Incorporated to forecast residential and commercial gas demand
in Fairbanks.The text of this report appears in Appendix E.
The potential residential and commercial demand for natural gas in the
Fairbanks area is dependent on the price competitiveness of natural gas
with respect to No.2 distillate fuel oil and propane in heating and
water heating markets,and its price competitiveness with propane and
electricity in cooking applications.The potential demand of natural gas
as a cooking fuel is estimated to be less than 5.0 percent of the total
potential demand for natural gas even if the gas were to fully displace
bottled propane in commercial cooking applications.
The forecasts of potential gas demand have been made conditional on the
gas achieving discrete percentages of the total market for heating and
cooking energy no percent,25 percent,40 percent,and 100 percent
displacement of fuel oil and propane in heating and of propane in
cooking).The size of the total market to which these percentages have
been applied has,in turn,been projected to grow at a 1.43 percent
annual average rate from 1981 for the low growth forecast,and at a 2.30
2648B
4-39
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percent annual average rate for the medium growth forecast.These growth
rates are the rates of Fairbanks population growth implied,respectively,
by Battelle's (1982)low forecast of the demand for electricity in the
Railbelt area,and Acres American's (1981)medium forecast of Railbelt
electricity demand.
The prices at which residential and commercial users would have a minimum
financial incentive to convert from fuel 0;1 to natural gas for heating
purposes have been derived.These "consumer breakeven"prices are based
upon the assumption that the maximum discounted payback period for
consumers is 5 years.At the 1982 price of No.2 distillate,$1.22 per
gallon,the calculated consumer breakeven prices are $9.58 per MCF for
residential heating and $9.94 per MCF for commercial heating.These
pric~s will ri se annually at approximately the real (i nfl ati on free)rate
of increase of fossil fuel prices in general.If this rate is the 2.0
percent real rate assumed by Battelle (1982)and Acres (1981),by the
year 2010 the breakeven prices in (1982 dollars)will have reached $16.68
per MCF (residential)and $17.31 per MCF (commercial).
The presence of calculated breakeven prices is necessary for the
forecast;ng of natural gas demand.However,breakeven price data and
price elasticity data are insufficient for such a forecast in this case.
These price and elasticity data are insufficient because the situation
involves a new product (natural gas)competing with an existing product
(e.g.,distillate oil,propane).Additional factors influence consumer
demand inclUding:1)consumer perceptions of the two products;2)
consumer inertia;3)initial and/or unusual incentives offered by
suppliers of the competing fuels based upon their calculated present
worth of achieving certain market shares;and 4)other less defined
factors.Because of these unquantified factors,conditional demand
estimates have been forecast;and these are based upon price analysi s
alone.
If natural gas is priced below the consumer breakeven level,users will
have an increased financial incentive to shift from fuel oil.For every
10¢by which the price of gas falls below the breakeven level,
26488
4-40
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residential users will realize approximately $81.00 (in 1982 dollars)in
additional savings over the estimated cost of conversion.It might be
expected that extensive inroads against fuel oil will begin to be made if
gas is priced sufficiently below breakeven so as to cover conversion
costs and to achieve a significant level of savings (measured as the
excess of the present value of annual cash savings over conversion costs.)
It must be recognized that the producers and suppliers of fuel oil are
likely to respond to the intrusion of natural gas by either lowering the
price of No.2 distillate or by offering other incentives.While the
intensity of reaction by oil suppliers cannot be forecast,it can be
assumed that suppliers are capable of at least offsetting the price
advantage that natural gas has traditionally enjoyed based on its
reputation as a "c l ean lJ fuel.Therefore,the above calculation of
consumer breakeven pri ces correctly ignores the fact that man,y consumers
might be willing to pay a premium for such natural gas properties.
DELIVERED GAS,BCF PER YEAR
1985 2010
The conditioned demand projections derived are presented in detail in
Appendi x E and are sununarized below for the medium growth projection.
These values represent the annual demand for delivered gas conditional
upon the percentage of market penetration indicated,where the total
market,defined in terms of effective MMBtu'sl!is set equal to 100
1/Effective MMBtu's (million Btu's)are delivered MMBtu's adjusted
for the fuel burning efficiency of heating units and cooking
units.For example,if oil burners are 65 percent efficient,one
delivered MMBtu equals 0.65 effective MMBtu's..
0.931
2.328
3.726
9.314
0.527
1.319
2.110
5.274
10%of Market
25%of Market
40%of Market
100%of Market
MARKET GROWTH @ 2.30 PERCENT
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4-41
1/Heat loss is proportional to the indoor-outdoor temperature
differential and inversely proportional to the insulation factor.
At an indoor temperature setting of 65 0 Fahrenheit,relative monthly
heating degree days is the appropriate measure of relative monthly
heat loss.
percent of commercial and residential heating energy requirements plus
29 percent of residential cooking energy requirements.The delivered
.gas demand values were calculate'd based upon different thennal
efficiencies for oil and gas fired units.
Peak daily demand during the month of January can reasonably be
estimated as 0.0322 (1/31)of the monthly demand times a factor that
all ows for extremes of col d.Between 1961 and 1982,the highest number
of January heating degree days recorded in Fairbanks was 3002 (in
January 1971).The January average was 2384.The ratio of the two
The demand for gas would not be constantly distributed throughout the
year.Based on an appraisal of normal monthly heating degree days in
Fairbanks,and an assumed indoor temperature setting of 65 0 Fahrenheit,
approximately 16.6 percent of annual Fairbanks heating energy is
consumed in Janua~,the peak month for demand.1/Although cooking
energy requirements may be more evenly spread across the year,the
relatively small size of cooking demand,less than 5.0 percent of the
total,suggests rather strongly that an apportionment of total demand
according to the conductive heat transfer formula will yield a good
estimate of peak monthly demand.Use of this method implies the
following peak monthly demand (January)for natural gas in Fairbanks
for the medium growth projection.
0.155
0.386
0.619
1.546
0.087
0.219
0.350
0.875
DELIVERED GAS,BCF PER PEAK MONTH
January January
1~5 2mO
MARKET GROWTH @ 2.30 PERCENT
10%of Market
25%of Market
40%of Market
100%of Market
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4-42
~·~rn_"i.~----~-•_
DELIVERED GAS,BCF,PEAK DAILY
January January
1985 2010
Peak hourly demand,defined as 0.0417 (1/24)times peak daily demand is
quite small.For examp1 e,in the maximal case of 2.30 percent growth
and 100 percent market penetration,the peak hourly demand is only
0.0026 BCF,or 2,600 MCF.
(1.26)when multiplied by 0.0322 yields an appropriate measure of peak
daily demand when their product is in turn multiplied by peak monthly
demand.Thus,peak daily demand equals 0.0406 times peak monthly
demand.The daily peaks are given in the following table for the
medium growth projection:
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MARKET GROWTH @ 2.30 PERCENT
10%of Ma rket
25%of Market
40%of Ma rket
100%of Market
0.004
0.009
0.014
0.036
0.006
0.016
0.025
0.063
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Finally,expansion of the Fairbanks steam district heating system could
reduce the demand for natural gas below the estimates presented above.
On the assumption that the district heating system supplies only
commercial and government us~rs,the implied reduction is at most 15.0
percent of the estimates given above,since commercial use of gas is
projected to be at most 15.0 percent of total demand.
4.4.2 Fairbanks Gas Distribution System
The Fairbanks natural gas transmission and distribution system will be
designed in conformance with Part 5,Alaska Public Utilities
Commission,Chapter 48,Practice and Procedures;Federal Safety
Standards for Transportation of Natural Gas and Other Gas by Pipeline,
49 CFR Part 293,Latest Revision;and the American National Standard
Code for Gas Transmission and Distribution Piping Systems,B 31.8,
Latest Edition.
2648B
4-43
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The overall system network will consist of a transmission lateral from
a metering station near Fox to a City Gate Station with a minimum inlet
pressure to the gate station of 250 psig.a 125 psig high pressure
system to distribute gas to district regulators.and a 60 psig maximum
distribution system to carry gas to individual customer services.
Generally.the rural facilities wi'll be considered in Location Class 3.
and those in the urban areas in Location Class 4.
4.4.2.1 Gas Transmission Line
The gas transmission line will connect to the 22-inch pipeline near Fox
(Figure 4-10).The line will be in pUblic right-of-way.adjacent to
the traveled roadway.The line will follow the Steese Highway to the
intersection of Farmers Loop Road to the City Gate Station.This is
approximately 12 miles of transmission line.
As load develops north of the Chen a Hot Spring Road along the Steese
Highway and McGrath Road.a secondary tap and gate station might be
considered at the intersection of Chena Hot Spring Road and the Steese
Highway for service to this northern load.and as a backfeed to the
McGrath and Farmers Loop Road facilities.
The transmission line will operate at the main pipeline pressure of
approximately 1.000 psig at the take-off point and have a design
pressure of 1.260 psig.The gas flow will be metered at the take-off
point.
The transmission line has been designed to provide peak hour coverage
for commercial and residential customers in the year 2010.At this
point.depending on actual growth and the location of additional supply
sources.the transmission line may have to be supplemented.The 2010
peak hour projections were used to determine the range of transmission
line sizes required.
26488
4-44
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1.HkItI PM8SmE OISTRIBUTKtN FAOM ern OAT'I 8tAl'lOt4 AT US PSIO.
I.lOW mEGat.A:.DtSTRUUTKtN FADM LOAD CENtf:h At 80 "10 '
J.LOAD C~NT"-R9 @.@."NO @ FOR FUTURE USE.
ALASKA POWER AUTHORITY
HORTH SLOPE GAS
FUSIBILfTY STUDY
CITY OF FAIRBANKS
GAS DISTRIBUTION
"QUI'IE 4-10
!BASCO SERVICES INCOAPOAA TED
4.4.2.2 City Gate Station
The City Gate Station will be designed for an incoming gas pressure of
1,260 psig.The nonna1 incoming operating pressure could drop as low
.as 250 ps ig during the medium forecast peak daily f10wrates.The
outlet pressure wili be 125 psig.Gas heating equipment may be
required to prevent the gas temperature from dropping below _20 0 F.
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The vicinity of the intersection of Fanners loop Road and the old
Steese Highway appears to be a suitable location for the City Gate
Station.No specific inquiries were made as to availability and cost
of vacant land in the area.The station will be above ground and can
be accommodated on an average city lot.
United States Geological Survey (USGS)maps indicate that this is a
penna frost area.One test bore in the immedi ate area indicates that
pennafrost begins at a depth of 19 feet.Further analysis will have to
be made to detennine soil and foundation conditions before any land
commitments are made.
Gas metering,conditioning,pressure reduction and flow control are the
basic functions that will take place at the gate station.It is
anticipated that the meter runs,control valves,odorization equipment
and instrumentation devices will be indoors.A single story concrete.
block or insulated corrugated metal building approximately 20 1 x 50'
would fulfill the requirement.
Gas purity is a major concern to distribution companies and
specifications are incorporated into gas purchase contracts.The North
Slope gas conditioning facility,however,will produce a pipeline gas
that meets typical specifications for domestic and commercial natural
gas.It is therefore assumed that the only gas processing required at
the gate station will be particulate and liquids removal carried over
from the North Slope to Fairbanks pipeline after primary processing has
been accomplished.
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Suspended solids and liquids will be removed prior to pressure
reduction by means of a conventional scrubber,and liquid resulting
from the condensation phenomena accompanying pressure reduction will be
removed by liquid knockout drip pots.
A gas odorization system will be part of the gate station facilities.
The system will be designed to maintain a relatively constant rate of
odorization with varying gas volumes.A liquid injection system based
upon gas volume measurement is anticipated.The odorization rate will
be in the range of 0.25 to 1.00 pounds odorant per million cubic feet
of gas.
Pressure reduction from 1,000psig inlet pressure to 125 psig station
outlet pressure will be accomplished at the gate station.Conventional
pressure reducing valve(s)with pilots and bypasses will be used.The
outlet of the gate station (inlet to high pressure system)will also be
provided with overpressure protection.An atmospheric relief sized to
relieve at the maximum allowable operating pressure plus 10 percent or
series monitor regulation will be considered.
Metering and gas flow control will take place at parallel meter runs.
Station flow will be remotely controlled by the gas dispatcher from the
headquarters office.Remote control telemetering will allow the
station to be nonna11y unmanned.
4.4.2.3 High Pressure System
The high pressure system will operate at an inlet pressure of 125 psig
from the City Gate Station.It is expected to traverse public
rights-of-way adjacent to traveled roads as shown on the conceptual
gri d map (Figure 4-10).Lateral s will branch off to load centers where
pressure reduction and overpressure protection will be provided at
district regulating stations.From these regulator stations,gas will
be distributed to the individual 60 psig networks.
2648B
4-47
HIGH PRESSURE SYSTEM MAINS
Individual high pressure mains are sized based upon peak hour load
center estimates using the Spitzglass high pressure formula.The sizes
and footages of the high pressure mains based upon the preliminary
network analysis are listed below.The high pressure system will be
standard wall API 5L GR.B steel pipe as requi~ed.
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8 11
1011
12 11
14 11
18 11
Length -Feet
6,000
15,000
27,375
7,500
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4.4.2.4 District Regulators
District regulator stations will be located at the inlet to 60 psig
distribution networks as shown on Figure 4-10.These fifteen (15)
stations will be designed to reduce the inlet pressure to 60 psig,and
to provide overpressure protection for the distribution system.The
method of overpressure protection (e.g.,,atmospheric relief,monitor
regulators,etc.)will be determined during final design.
The type of construction and location of district regulator stations
will also be determined during final design.The options of
underground vault versus aboveground station construction must be
reviewed with respect to considerations of the availability of public
ri ght-of-way,private easement,soil and groundwater characteri sties,
equipment operating capabilities and safety.
4.4.2.5 Distribution Systems
The distribution systems as shown onFigure 4-10 will deliver maximum
60 psig and minimum 15 psig gas to individual customer services.The
lines will be polyethylene pipe,PF 3408 per ASTM 0 2513.The pipe
will be SDR 11 for Class 4 locations and SDR 13.5 for Class 3
2648B
4-48
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SCHEDULE OF DISTRIBUTION MAINS
Residential temperature compensated meters sized for this demand load
must also satisfy the following specifications:
Services will be sized to deliver gas for maximum e~timated demand of
approximately 225 cubic feet'per hour (CF/HR).
Residential regulators sized to deliver the demand load at an inlet
pressure range 15 to 60 psi g and an outl et pressure of 611 to 711 W.C.
will be specified for residential customers as standard.
Length -Feet
450.000
78.000
87.000
2.250
1.500
-O.Sf!W.C.
-30 0 F
-]'I W.c.
-_70 0 F
211
4 11
6 11
811
12 11
Size
Maximum pressure drop
Gas temperature
Inlet pressure
Ambient air temperature
The distribution lines will be laid in public rights-of-way at a depth
of three feet to the top of the main.The lines will be laid on the
opposite side of the road from existing or proposed water mains.The
estimated footages by size of distribution mains are tabulated below.
locations.The smoother inside surface of plastic pipe allows the same
sizes as steel pipe to handle the higher f10wrates.Individual lines
will be sized using the Spitzg1ass fonmu1a.In general.distribution
lines will be 211 as standard.Larger size lines will be the
exception.Distribution lines will be valved to comply with Gode
requirements and good operating practices.
4.4.2.6 Residential Services
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Residential services will be standardized as welded and wrapped steel.
The meter and regulator wil1 5 when desirable,be in the basement.The
service will have a curb cock where the meter and regulator is indoors.
If a service meter/regulator set cannot be pl aced i ndoors 5 consideration
,,
will be given to enclosing them in a metal or wooden,insulated and
heated enclosure.In this case,a curb cock m~not be required.The
service head will be designed to allow for flexibility of movement due to
frost heave and settlement.
Services will be sized for a 1.5 to 3 psig maximum allowable pressure
drop'for inlet pressur.es of 15 psig minimum to 60 psig maximum.
Assuming an average service length of 100 feet (allowing for equivalent
length for fittings)5 and a 15 psig inlet pressure and a maximum 1.5 psig
pressure droP5 a 1/211 steel service has the capacity of 395 CF/HR at a
specific gravity of 0.65 and a temperature of 30°F.This is in excess
of the 225 CF/HR estimated maximum residential demand,and the allowable
pressure drop is not exceeded.Therefore 5 a system standard of 1/2 11
service size will be used for the average residential customer.
4.4.2.7 Convnerci al /Industri a1 Services
Commercial/industrial services will be designed and constructed following
the same general procedures as for residential services.However,no
attempt is made to standardize on size.Rather 5 each service will be
sized to meet its special load requirements.In addition 5 it is highly
possible that some convnerci al /i ndustri al customers may be better served
from a 125 psig main.In these cases 5 the requirement of dual regulation
or other secondary overpressure protection will be provided in the
service design.
4.4.2.8 Headquarters Building
The headquarters building will contain office space for the gas dispatch
and operating personnel.It will also include telemetry for controlling
2648B
4-50
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gas flow at the City Gas Station.Building size will be approximately
25'x 50'single story,constructed of concrete block or insulated
corrugated metal suitable for climatic conditions in Fairbanks,Alaska.
4.4.2.9 Cold Temperature Design and Environmental Factors
The Fairbanks gas distribution facilities will be designed to meet or
exceed the most stringent applicable minimum construction and safety
standards.However,there are technical considerations which are not now
specifically covered by code which must be investigated in great detail
and solutions deve1op~d prior to final site selection and completion of
detailed design.In addition,there are environmental considerations
which must be investigated and addressed more fully during the design
phase of the project.Among these are:
1.Pennafrost and Frost Heave
2.Field (hydrostatic)Testing
3.Cold Temperature Operation of System Components
4.River and Stream Crossings
5.Ice Fog
Permafrost and Frost Heave
United States Geological Survey data for the area of the gas distribution
system has been reviewed.This review indicates that the distribution
system will traverse three general i zed units of subsurface conditions.
These are the Tanana-Chena River Flood Plain,the Upland Hills,and the
Creek Valley Bottom formations.
The Tanana-Chena River Flood Plain consists of alternating layers of
alluvial silt,sand and gravel.The top silt layers ranges from 1 to 15
feet thick.Permafrost is discontinuous and randomly located and ranges
in depth to the top from 2 to 4 feet in older parts of the flood plain,
and to 25 to 40 feet in cleared areas.Where frozen,silt has a low to
moderate ice content in the form of thin seams.The silt will develop
2648B
4-51
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some subsidence when thawed,and may undergo intense seasonal frost
heave.The portion of the distrjbution system "in town"is generally in
the flood plain fonmation •
Adjacent to the flood plain are gently rolling bedrock hills covered.by
from 3 to 200 feet of windblown silt (loess).The Upland Hills are
generally free of permafrost although perennially frozen silt does occur
along the base of most hills.Portions of the transmission lateral along
the Steese Highway traverse this formation,as do portions of the
distribution system along Farmers Loop Road.
The valley bottoms of the upland contain this silt accumulations that are
perennially frozen and h~ve high ice content.The depth to permafrost is
from 1-1/2 to 3 feet on lower slopes and valley bottoms,from 5 to 20
feet near contact with the unfrozen silt zone,and from 10 to 25 feet in
cl eared areas.
The seasonal frost layer is from 1-1/2 to 3 feet thick.Seasonal frost
action is intense,and there is great subsidence when permafrost thaws.
Sections of the transmission lateral along the Steese Highway as well as
part of the distribution system along Farmers loop road cross this
formation.In addition,the proposed location of the City Gate Station
is within the limits of the Creek Valley Bottom formation.
The relation made between the distribution system and area geology above
is based upon subsurface fonnation areas generally described on U.S.G.S.
Quadrangle Maps.Local variations may occur,particularly near the
interface between fonnations.Therefore,a detailed analysis of soil
conditions along the proposed right-of-way will be necessary to detennine
where and to what extent frost susceptible soil and/or permafrost exist.
Final facilities location and design must be based upon flowing gas
temperatures within the system and subsurface soil survey and analysis.
Systems operating temperatures,at one-extreme,may cause thermal
degradation of pennafrost,and at the other extreme frost heave may be
2648B
4-52
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the problem.In either case,specialized design may be necessary to
assure that the i ntegri ty of the'system and/or the envi ronment are not
jeopardized.
Field (Hydrostatic)Testing
The detailed design phase of the project will result in final
deternlination of the pipe specifications for the project.These will be
based upon the balance of service performance expectations and the
economics of purchase and installation.At that time,the final code and
permit requirements with respect to testing will be more exactly known.
Hydrostatic testing will require that procedures and specifications
address testing at ambient air temperatures be10w 32°F.~and dewatering
and IIdrying"of pipe lines after testing.In addition,cold temperature
testing will require a review of brittle fracture mechanics for the
specified pipe material.
As generally designed now,the 60 psig distribution system would be
pneumatically tested to 100 psig.The 125 psig high pressure system
would be hYdrostatically tested to 175 psig.The transmission lateral
would be tested hydrostatically to 1.4 times the maximum operating
pressure.
System Component Operation
The effects of subarctic temperatures and the temperature of flowing gas
will require particular attention and perhaps specialized design to
assure long,trouble free operation of the system.Among the areas where
special effort may be required are:
Gas Meters:Di aphragm materi a1 s with acceptable lower operating
temperature limit to _70 0 F.must be provided.
Potential condensate problems must be analyzed.
Shut Off Valve:Lubricant freeze up potentials must be investigated.
Valve box and operating nut accessibility in frozen
snow and ice must be reviewed.
2648B
4-53
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considered.Stresses resulting from cold temperature
must be considered in design.
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Effects of cold temperature and condensate freeze up
on diaphragm and valve discs must be studied.
River and Stream Crossings
The conceptual system layout indicates that there are nine river and
creek pipeline crossings.They are:
Jessela Creek at Farmers Loop Road
Isabella Creek at Farmers Loop Road
Pearl Creek at Farmers Loop Road
Chena River at N.Hall Street
Noyes Slough at Illinois Street
Noyes Slough at Alder Avenue
Deadman Slough at Geist Road
Deadman Slough at Loftus Road
Deadman Slough at Fairbanks Street
It is anticipated that the major crossing can be made using existing
bridges.These will require close interface with highway officials and
engineers.Specialized design for support,thermal movement,
installation procedures,and protective coating may be necessary.
Those crossings for which a bridge crossing is not possible will require
that stream flows,bed movement and scour,and potential fishery impacts
be analyzed,and that appropriate design and construction procedures be
developed accordingly.
Ice Fog
Ice fog is a serious and complex problem which is still being studied.
Many solutions have been suggested to reduce the occurrence of ice fog.
The principal focus has been on reducing water vapor emissions from the
generation of heat and power.It is understood that as the quantity of
water vapor released to this atmosphere is reduced,the temperature at
which ice fog forms will decrease away from zero,thus decreasing the
frequency of occurrence.Any design of a gas distribution system in
2648B
4-54
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Fairbanks must include appropriate measures to reduce water vapor
released to the atmosphere.
4.5 COST ESTIMATES
4.5.1 Capital Costs
4.5.1.1 North Slope to Fairbanks Natural Gas Pipeline
Order of magnitude,investment cost estimates have been prepared for the
systems and facilities which comprise the North Slope to Fairbanks
natural gas pipeline.These estimates are presented in Table 4-14.
4.5.1.2 Power Plant
To support the derivation of total systems costs which are presented in
Section 4.5.4,order of magnitude investment costs were developed for the
major bid lines items common to a 77 MW (ISO conditions)natural gas
fired simple cycle combustion turbine and a 220 MW (ISO conditions)
natural gas fired combined cycle plant.These costs are presented in
Tables 4-15 and 4-16.The costs represent the total investment for the
first unit to be developed a~the site.Additional simple cycle units
will have an estimated investment cost of $33,900,000 while additional
combined cycle units will have an estimated investment cost of
$127,430,000.The cost differential for additional units is due to
significant reductions in line items 1 and 15,improvements to Site and
Off-Site Facilities,and reductions in Indirect Construction Cost and
Engineering and Construction Management.
4.5.1.3 Transmission Line Systems
Transmission line order of magnitude investment cost estimates for the
Fairbanks to Anchorage connection are presented in Table 4-17.These
estimates are based on two new 345 kV lines,in parallel,1400 MW
capaci ty,wi th seri es compensati on and an ;ntermed;ate swi tchi ng
2648B
4-55
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TABLE 4-14
ORDER OF MAGNITUDE INVESTMENT COSTS
NORTH SLOPE TO FAIRBANKS NATURAL GAS PIPELINE
(January,1982 Dollars)
Description!!
Materi al s Cons~ruction Total Di rect
($1000)Labor_/($1000)Cost ($1000)
--_.---
22 in 0.0.Gas Pipeline 480,000 4,100,000 4,580,000
Compressor Stations -10 ea 96,800 83,400 180,200
Metering Stations - 2 ea 2,800 6,000 8,800
Valve Stations -28 ea 2,500 3,800 6,300
Engineeri ng &Construction 28,700
Management
SUBTOTAL $582,100 $4,193,200 $4,804,000
Gas Conditioning Facil ity~/780,000
TOTAL CONSTRUCTION COST $5,584,000
1/A 15 percent contingency has been assumed for the entire project and
has been di stri buted among each of the cost categories shown.
Sales/use taxes and land and land rights expenses have not been
included.
~Construction camp facilities and services are subsumed in the
Construction Labor cost category.
3/Factored pricing basis which includes engineering and construction
management costs.
2648B
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TABLE 4-15
ORDER OF MAGNITUDE INVESTMENT COST ESTIMATES
77 MW SIMPLE CYCLE COMBUSTION TURBINE
(January,1982 Dollars)
Construction Total
De scri pti on.~./f~ateri al s Labor Di rect Cost
($1000)($1000) ($1000)-_..-_._---_._~
l.Improvements to Site 405 1,240 1,645
2.Earthwork and Piling 195 345 540
3.Circulating Water.System 0 0 0
4.Concrete 475 2,145 2,620
5.Structural Steel Lifting 1,725 1,370 3,095
Equipment,Stacks
6.Buildings 750 1,440 2,190
7.Turbine Generator 11,100 650 11 ,750
8.Steam Generator and Accessories 0 0 0
9.Other Mechanical Equipment 460 235 695
10.Pi ping 205 510 715
ll.Insulation and Lagging 30 110 140
12.Instrumentation 100 70 170
13.El ectri ca 1 Equipment 1,510 2,590 4,100
14.Pa i nting 70 250 320
15.Off-Site Facilities 300 1,080 1,380
SUBTOTAL $17,325 $12,035 $29,360
Freight Increment 865
TOTAL DIRECT CONSTRUCTION COST $30,225
Indirect Construction Costs 1,665
SUBTOTAL FOR CONTINGENCIES 31,890
Conti ngenci es (15%)4,790
TOTAL SPECIFIC CONSTRUCTION COST 36,680
Engineering and Construction 2,200
Management
TOTAL CONSTRUCTION COST $38,880
1/The following items are not addressed in the plant investment pricing:
laboratory equipment,switchyard and transmission facilities,spare
parts,land or land rights,and sales/use taxes.
----------------------------~---
2648B
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TABLE 4-16
ORDER OF MAGNITUDE INVESTMENT COSTS
220 MW COMBINED CYCLE PLANT
(January,1982 Dollars)
Total
Construction Di rect
De sc ri pti oo.!/
Materi al Labor Cost
($1000)($1000)($1000)
-----
l.Improvements to Site 425 1,295 1,720
2.Earthwork and Piling 570 1,050 1,620
3.Circulating Water System 0 0 0
4.Concrete 1,485 6,730 8,215
,5.Structural Steel Lifting 3,800 3,530 7,330
Equipment,Stacks
6."Buildings 1,800 3,600 5,400
7.Turbine Generator 30,100 2,520 32,620
8.Steam Generator and Accessories 9,600 4,320 13,920
9.Other Mechanical Equipment 6,735 3,425 10,160
10.Pi ping 1,500 2,910 4,410
1l.Insulation and Lagging 290 690 980
12.Instrumentation 1,700 290 1,990
13.Electrical Equipment 4,550 8,640 13,190
14.Pa i nting 200 720 920
15.Off-Site Facilities 300 1,080 1,380
SUBTOTAL $63,055 $40,800 $103,855
Freight Increment 3,155
TOTAL DIRECT CONSTRUCTION COST $107,010
Indi rect Construction Costs 4,235
SUBTOTAL FOR CONTINGENCIES 111,245
Contingencies (15%)16,685
TOTAL SPECIFIC CONSTRUCTION COST 127,930
Engineering and Construction 6,800
Management
TOTAL CONSTRUCTION COST $134,730
1/The following items are not addressed in the plant investment pricing:
laboratory equipment,switchyard and transmission facilities,spare
parts,land or land rights,and sales/use taxes.
---------------
2648B
4-58
l!The investment costs reflect two new 345 kV lines,1400 MW capacity,with
series compensation and an intermedi ate switchi ng stati on and upgradi ng
of the Willow-Anchorage and Healy-Fairbanks segments of the existing grid
to 345 kV.
2/Assumes a cost of $40,000 per mile (Acres American Inc.1981).
TABLE 4-17
ORDER OF MAGNITUDE INVESTMENT COSTS
FAIRBANKS TO ANCHORAGE TRANSMISSION SYSTEM
(January,1982 Dollars)
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De scri pti on!!
Switching Stations
Substations
Energy Management Systems
Steel Towers and Fi xtures
Conductors and Devices
C1 eari ng
SUBTOTAL
Land and Land Ri9hts~
Engineering and Construction
Management
TOTAL CONSTRUCTION COST
Materi al
($1000)
14,112
62,308
12,300
216,495
33,678
$388,893
Constructi on
Labor ($1000)
12,445
41,716
10,960
305,085
78,361
83,144
$531,711
Total
Di rect Cost
($1000)
26,557
104,024
23,260
521 ,580
112,039
83,144
$870,604
27,600
60,950
$959,154
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station.The investment cost estimatesal so refl ect upgradi ng from
138 kV to 345 kV of the Wi 11 ow-Anchorage a nd Healy-Fa i rbanks segments
of the existing grid.
4.5.1.4 Gas Distribution System
Order of magnitude,investment cost estimates (January,1982 dollars)
have been prepared for the systems and facil ities which compri se the
Fairbanks gas distribution system.The results of the analyses are
given below.A 15 percent contingency has been assumed for the entire
project and has been distributed between each cost category.Sales/use
taxes and land rights have not been included.
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($1000)-"---
Gas Distribution System $11,500
Eng i neeri ng and
Co nstructi on Ma nagement
TOTAL CONSTRUCTION COST
4.5.2 Operating and Maintenance Costs
Constructi on
Labor ($1000)
$48,200
Total Di rect
Cost ($1000)-"_.-
$59,700
3,582
$63,282
4.5.2.1 Gas Pipeline and Conditioning Facility
Annual Operating and maintenance costs (January,1982 dollars)for the
gas conditioning facilities are estimated to be as follows:
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Sal aries
Maintenance Costs (Parts and
Expendables)
TOTAL
4-60
ANNUAL COSTS ($1000)
$2,480
3,750
$6,230
Annual operating and maintenance costs (January,1982 dollars)for the gas
compressor stations and pipeline maintenance activities are estimated to be
as foll ows:
Operating and maintenance costs for the combined cycle facility at
Fairbanks are estimated to be $0.0040/kWh.These are based on
di scussi ons with operati ng pl ant personnel,hi story of simil ar units,
El ectri c Power Research Institute data,pub1 i shed data and other
studies performed.
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Sal aries
Maintenance Costs (Parts,
Expendables,Other)
TOTAL
4.5.2.2 Power Plant
ANNUAL COSTS ($1000)
$4,400
5,850
$10,250
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4.5.2.3 Transmission Line Systems
Annual operating and maintenance costs (January 1982 dollars)have been
developed for the scenario's required transmission line facilities and
total $12 million per year.These costs should be viewed as an annual
average over the life of the system.Actual O&M costs should be less
initially,and will increase with time.
4.5.2.4 Gas Distribution System
Annual operating and maintenance costs (January 1982 dollars)for the
Fairbanks gas distribution system are estimated to be as follows:
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Maintenance Costs
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ANNUAL COSTS ($1000)
$1,290
500
$1,790
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4.5.3 Fuel Costs
For the economic analyses which follow fuel costs were treated as zero.
This approach permits fuel cost and fuel price escalation to be treated
separately;and makes possible subsequent sensitivity analyses of the
Present Worth of Costs for thi s scenari 0 based upon a range of fuel cost
and cost escal ati on assumpti ons.
4.5.4 Total System Costs
4.5.4.1 Cost Allocation ~1ethodology
For purposes of total system cost compari sons,natural gas pipel i ne
conditioning plant and pipeline costs from the North Slope to Fairbanks
must be allocated between electricity generation applications and
resi denti al /col1111erc i al customer appl i cati ons.In thi s way the
non-electric system costs can be removed from the total cost comparison
associated with electricity supply.Two types of costs must be
allocated:(1)capital investment costs;and (2)annual costs,including
operating and maintenance (O&M)costs and fuel costs (e.g.,for pipeline
comp ressor stati ons).
Capital cost allocation is based upon the peak demand for natural gas,
and consequently the capaci ty requi rements of the 1 i nee In thi s
allocation it is useful to make the conservative assumption that both
peak loads may occur simultaneously.Given that assumption,the
following formulas can be used to allocate capital costs:
PE/(P E +PR)=0 1
01 (I Ge +I p )=ESCC
(1)
(2)
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PE =
PR =
°1 =
IGC =
I =
EgCC
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peak natural gas demand for electricity generation
peak natural gas demand for residential and commercial uses
the proportion of investment costs charged to electricity
generation
capital investment in the conditioning plant
capital investment in the pipeline
=electric service related capital charges
4-62
Annual costs are allocated on an energy basis rather than on a capacity
basis.Those costs are allocated by the following formula:
Again,disaggregation may be accomplished for O&M or fuel costs;and
this is accomplished by multiplying the 0A term by either SCO+M or
SC F.Again,only shared costs are consid~red,and user community-
specific costs are not considered.
Given these formul ae,costs may be di saggregated.Costs may be
allocated to residential and commercial users by substituting (1-01)
for 01 and (l-OA)for 0A'Precise comparison of the electrical
generation options can now be accomplished.
The second formula arrives at the specific dollar value for allocation
purposes.It can be applied either to I GC or I p separately when
capital costs must be disaggregated by component,or as shown for the
total capital burden.Neither formula is applied to investments that
are specific to one user community (e.g.the residential gas
distribution system),as those investment costs must be borne totally
by the appropriate users.
(3)
(4)
(5 )
total shared annual charges
shared 0 &M costs
shared fuel costs
annual natural gas consumption for electricity generation
annual natural gas consumption by residential and
commercial users
the proportion of annual costs charged to electricity
generation
electrical service related annual costs
SCA =SCO+M +SC F
EC E (EC E +EC R)=°A
0A x SCA =ESAC
ESAC =
o -A -
Where:
SCA =
SC OfM =
SC F =
EC E =
EC R =
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4.5.4.2 Power Generation System Costs
,
The Fairbanks medium load growth scenario is far more complex than the
Prudhoe Bay medium load growth scenario in that it includes:(1)a
gas conditioning facility,(2)a natural gas pipeline,(3)power
generation facilities,and (4)transmission line facilities.
Further,the conditioning plant and pipeline fac'ilities serve both
electricity and residential/commercial markets.As a consequence,the
capital,operating and maintenance,and fuel costs associated with the
conditioning facility and pipeline must be apportioned to the
respective user communities.
The method for apportionment has been previously described (see Section
4.5.4.1).On this basis Or and 0A values are calculated (0 refers
to the fraction of costs apportioned to the electricity segment of the
natural gas market).Or'the capital cost apportionment term,is
calculated as follows for the medium load forecast:
Residential/Commercial =63 MMSCFD
Peak Daily Flow (2010)
Electricity Generation =271 MMSCFD
Peak Daily Flow (2010)
Total Peak Daily Flow =334 MMSCFD
Or =0.82
0A'the annual costs apportionment term,varies over time for the
medium load forecast.Values for 0A are presented in Table 4-18.
Gi ve n the apporti onment terms,the annual systems costs for the
electricity generation system can be presented.The annual capital
expenditures are shown in Table 4-19.The annual non-fuel O&M costs
are shown in Table 4-20.The annual fuel costs,based upon a wellhead
price and escalated at 2 percent per year (above inflation)are shown
in Table 4-21.The summary of total systems costs is presented in
Tabl e 4-22.
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TABLE 4-18
o ,VALUES!.!A
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST
Resi denti al El ectri cal Total
Calendar Demand Demand DemandrYear(BCFY)(BCFY) (BCFY)°A
---_._-----
r 1982 O.O.O.NA?:.!
1983 O.O.O.NA
1984 O.O.O.NA
1985 O.O.O.NA
1986 O.O.O.NA
1987 O.O.O.NA
1988 O.O.O.NAr1989O.O.O.NA
1990 O.O.O.NA
1991 O.O.O.NAr1992O.O.O.NA
1993 1.219 6.266 7.485 0.84
1994 2.494 6.266 8.760 0.72
1995 3.827 12.532 16.359 0.77r19965.220 12.633 17.853 0.71
1997 6.676 25.133 31.809 0.79
1998 6.829 25.203 32.032 0.79r19996.986 25.203 32.189 0.78
2000 7.147 31.551 38.698 0.82
2001 7.311 31.467 38.778 0.81
2002 7.479 37.804 45.283 0.83
2003 7.651 37.804 45.455 0.83
2004 7.827 44.188 52.015 0.85
2005 8.008 45.809 53.817 0.85
2006 8.192 49.535 57.727 0.86
2007 8.380 53.146 61.526 0.86
2008 8.573 52.292 60.865 0.86r20098.770 55.893 64.663 0.86
201 0 8.971 59.425 68.396 0.87
r 1/Values as calculated are shown for purposes of reproducibility
only,and do not imply accuracy beyond 100 MMSCFD.
r 2/NA -Not applicable
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TOTAL ANNUAL CAPITAL EXPENDITURESrFAIRBANKSPOWERGENERATION-MEDIUM LOAD FORECAST
(Millions of January,1982 Dollars)
r Gas
Ca 1endar Electricity GeneratedL/Transmission ConditioningrYearUnitAUnitBLinePipelinePlant Total
r 1982 O.O.O.O.O.O.
1983 O.O.O.O.O.O.
1984 O.O.O.O.O.O.
r 1985 O.O.O.O.O.O.
1986 O.O.O.O.o.O•.
1987 O.O.O.O.O.O.
1988 O.O.514.2 O.O.514.2
,r 1989 o.o.118.1 1 ,313.1 O.1,431.2
1990 0"O.232.4 1 ,313.1 319.8 1,865.3
1991 9.91Y O.94.5 1 ,31 3.1 319.8 1,737.3r199233.90 O.O.O.O.33.9
1993 o.O.o.o.O.O.
1994 33.90 O.O.O.O.33.9
1995 56.97 o.o.O.O.57.0r199633.90 33.90 o.o.O.67.8
1997 56.97 o.o.O.o.57.0
1998 O.o.o.O.O.o.r 1999 33.90 o.O.O.O.33.9
.2000 o.O•o.O.O.o.
2001 33.90 56.97 o.o.O.90.0
r 2002 O.o.o.o.o.o.
2003 33.90 o.o.O.o.33.9
2004 33.90 56.97 o.o.O.90.9
2005 33.90 O.o.o.O.33.9
2006 33.90 O.o.O.O.33.9
2007 56.97 o.o.o.o.57.0
2008 33.90 o.o.o.O.33.9r200933.90 o.o.o.O.33.9
2010 0"O.O.O.o.O.
Total $554. $148.$959.$3,939.$640.$6,240.r
1/Unit B denotes a second unit erected in any give year.
f ?/Includes all site preparation activities for multiple unit site.
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TABLE 4-20
TOTAL ANNUAL NON-FUEL OPERATING AND MAINTENANCE COSTS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST
(Millions of January,1982 Dollars)
GasrCalendarElectricityTransmissionConditioning
Year Generated Line Pipeline Pl ant Total
1982 O.O.O.O.O.
1983 O.O.O.O.O.
1984 O.O.O.O.O.
1985 O.O.O.O.O.
1986 O.O.O.O.O.
1987 O.O.O.O.o.
r 1988 O.O.O.O.O.
1989 O.O.O.O.O.
1990 O.O.O.O.O.
1991 O.O.O.O.o.r 1992 O.O.O.O.O.
1993 2.260 12.0 8.61 5.23 28.1
1994 2.260 12.0 7.38 4.49 26.1
1995 4.520 12.0 7.89 4.80 29.2
1996 6.376 12.0 7.28 4.42 30.1
1997 10.880 12.0 8.10 4.92 35.9
1998 12.720 12.0 8.10 4.92 37.7
1999 12.720 12.0 8.00 4.86 37.6
2000 15.020 12.0 8.41 5.11 40.5
2001 14.980 12.0 8.30 5.05 40.3r200219.080 12.0 8.51 5.17 44.8
2003 19.080 12.0 8.51 5.17 44.8
2004 21.396 12.0 8.71 5.30 47.4r200523.120 12.0 8.71 5.30 49.1
2006 24.212 12.0 8.82 5.36 50.4
2007 25.300 12.0 8.82 5.36 5L5
2008 26.392 12.0 8.82 5.36 52.6
2009 27.480 12.0 8.82 5.36 53.7
2010 28.572 12.0 8.92 5.42 54.9
r Total $296.$216.$151.$92.$755.
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TABLE 4-21
TOTAL ANNUAL COSTS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST
(Millions of January,1982 Dollars)
Calendar Capital o &M Total
Year Expenditures Costs Expenditures
1983 o.O.O.
1984 O.O.O.
1985 O.o.O.
1986 O.O.O.
·1987 O.O.O.
1988 499.8 O.499.88
1989 1,431.2 O.1,431.22
1990 1,865.3 O.1,865.33
1991 1,737.3 O.1,737.33
1992 33.9 O.33.99
1993 O.28.1 28.14
1994 33.9 26.1 60.04
1995 57.0 29.2 86.29
1996 67.8 30.1 97.94
1997 57.0 35.9 92.94
1998 o.37.7 37.77
1999 33.9 37.6 71.57
2000 O.40.5 40.54
2001 90.9 40.3 131 .24
2002 O•.44.8 44.81
2003 33.9 44.8 78.72
2004 90.9 47.4 138.30
2005 33.9 49.1 83.03-2006 33.9 50.4 84.39
2007 33.9 51.5 85.43
2008 33.9 52.6 86.54
2009 33.9 53.7 87.63
201 0 O.54.9 54.90
Total $6,240.$755.$6,994.
Present
Worth @ 3%$4,787.$415.$5,202.
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For comparison purposes,the 1982 present worth of power generating
costs has been calculated,assuming a real discount rate of 3 percent
and excluding fuel costs.The present worth of costs,expressed in
1982 dollars,is $5.2 billion.The present worth of costs for the
Fairbanks gas distribution system is $0.9 billion.
4.5.4.3 Gas Distribution System Costs
The costs attributable to the gas distribution system are those costs
not associated with electricity generation.The capital costs include
a portion of,the gas conditioning plant,a portion of the pipeline,and
the Fairbanks residential/commercial gas distribution itself.
Operating and maintenance costs,and internal fuel requirements,must
be treated in a like manner.
In Section 4.5.4.2 the values for 01 and 0A were presented.
Allocation of costs to the gas distribution system require the
presentation of (1-0)1 and (1-0)A values;and these are presented
in Table 4-22.These are required because,by definition,1-0 defines
the portion of costs associated with joint investments attributed to
non-electric purposes.
Given such values,the annualized expenditures associated with the..
natural gas distribution system can be calculated.These are
summari zed in Tables 4-23 through 4-25.The present worth of all costs
associated with the distribution system,as of 1982,is $891 million
(JanuarY,1982 dollars),exclUding fuel costs.
4.6 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS
Environmental effects associated with the Fairbanks power generation
scenario will be similar in many respects to those of the North Slope
scenario.Because the pipeline from the North Slope to Fairbanks will
be buried and chilled,it will result in different environmental
effects and will require different types of mitigation than would a
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TABLE 4-22
APPORTIONMENT VALUES FOR THE GAS DISTRIBUTION SYSTEM
FAIRBANKS POWER GENERATION -MEDIUM LOAD SCENARIO
Tenn Year vafue
(l-Ol!NA!!0.18
0-0 )A 1982-1992 NA
1993 0.16
1994 0.28
1995 0.23
1996 0.29
1997 0.21
1998 0.21
1999 0.22
2000 0.18
2001 0.19
2002 0.17
2003 0.17
2004 O.15
2005 O.15
2006 0.14
2007 0.14
2008 0.14
2009 0.14
2010 0.13
1/NA -Not applicable
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TABLE 4-23
TOTAL ANNUAL CAPITAL EXPENDITURES FOR THE GAS DISTRIBUTION SYSTEM
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST
(Millions of January,1982 Dollars)
Gas Gas
Calendar Di stri buti on Conditioni n9
Year System·Pi pel ine Pl ant Total
1982 O.O.O.O.
1983 O.O.O.O.
1984 O.O.O.o.
1985 O.o.o.O.
1986 O.O.O.O.
1987 o.o.o.O.
1988 O.O.O.O.
1989 12.66 288.2 o.300.9
1990 12.66 288.2 70.2 371.1
1991 12.66 288.2 70.2 371.1
1992 12.66 O.O.12.7
1993 12.66 o.o.12.7
1994 O.O.O.o.
19-95 O.O.O.O.
1996 O.O.O.o.
1997 o.O.o.O.
1998 O.O.O.O.
1999 O.O.O.O.
2000 O.O.O.O.
2001 O.O.O.O.
2002 O.O.O.o.
2003 o.o.O.O.
2004 O.O.O.o.
2005 o.o.O.O.
2006 O.O.o.o.
2007 O.O.'..O.O.
2008 O.O.o.O.
2009 O.O.O.O.
2010 o.o.o.O.
Total $63.$865.$140.$1,068.
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transmission line through the same area.As in the North Slope
scenario,power plant emissions will be a significant consideration
because of existing air quality problems in the Fairbanks area.
Environmental impacts caused by the transmission line from Fairbanks to
Anchorage will be identical to those discussed for the North Slope
scenario,Sections 2.5 and 3.5,and are not repeated here.Power plant
characteristics related to environmental effects are summarized in
Table 4-26.
4.6.1 Air Resource Effects
Meteorological conditions in the Fairbanks area play a very important
role in detenmining the ambient air quality levels in the area.
Analyses of the Fairbanks urban IIheat island 'l have shown that winds are
generally light in the winter and that wind directions change
dramatically in the vertical direction during the wintertime.During
the winter months,the air near the ground is relatively cold,compared
to the air aloft.This reduces mixing of the air in the vertical
direction,and when combined with relatively light winds,often leads
to periods of air stagnation.
In large part due to the winter stagnation conditions,the Fairbanks
area is currently designated as a non-attainment area for carbon
monoxide (CO).Emissions of CO are largely due to automobiles.The
State Department of Environmental Conservation and the Fairbanks North
Star Borough Air Pollution Control Agency are implementing a plan to
reduce the ambient CO mainly through the use of vehicle emission or
traffic control techniques.In addition,relatively high levels of
nitrogen oxides have recently been monitored in the Fairbanks area.
Only an annual average nitrogen dioxide standard exists,but the short
tenn measurements of nitrogen oxides are as high as in major urban
areas such as Los Angel es.
The installation and pennitting of a major fuel-burning facility,such
as a power plant,will require a careful analysis of the impact of its
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Sulfur Dioxide Below Standards
Air Environment
TABLE 4-26
ENVIRONMENT RELATED POWER PLANT CHARACTERISTICS
FAIRBANKS POWER GENERATION -MEDIUM LOAD FORECAST
COMBINED CYCLE POWER PLANT
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Emissions
Particulate Matter Below Standards
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Nitrogen Oxides Emissions variable within standards -
dry control techniques would be used
to meet calculated NO x standard of
0.014 percent of total volume of
gaseous emissions.This value
calculated based upon new source
performance standards,facility heat
rate,and unit size.
PhYsical Effects Maximum structure height of 50 feet
Water Environment
Plant Water Requirements 200 GPM
Plant Discharge Quantity Less than 200 GPM
including treated sanitary
waste,floor drains,boiler
blowdown and demineralizer
wastes
Land Environment
Land Requirements
Plant 140 acres
Socioeconomic Environment
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Operating Workforce
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construction
Approximately 150 employed personnel
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emissions on ambient air quality.Because Fairbanks is a non-
attainment area,the operators of such a facility must demonstrate that
they will reduce,or offset,impacts of the power plant by reducing
emission levels of CO at other sources.Emissions of CO from a natural
gas-fired power plant are relatively low,and any displacement of the
burning of other fuels,such as coal or oil,will likely lead to
improved air quality.This arises from the clean-burning nature of
natural gas and from the fact that emissions from a major facility will
be injected higher in the atmosphere (due to plume buoyancy)than the
displaced emissions.During th~ve~stagnant conditions in midwinter,
the plume from a power plant will likely remain well aloft with little
mixing to the surface layers.The complex urban heat island and
associated wind pattern will require a great deal of in-depth modeling
·and analysis to determine air quality impacts in terms that will
wi thstand regul atory scruti ny.
A large combustion turbine power plant must meet the existing New
Source Performance Standards and Best Available Control Technology.
The nitrogen oxides limits will be the most constraining atmospheric
pollutant.The operation of the power plant will also consume a
portion of the allowable deterioration in air quality for nitrogen
oxides.While it is possible that the power plant could be sited near
Fairbanks,its installation would constrain other development efforts
which also might consume a portion of the air quality increment.The
nature,magnitude,and duration of emission plumes must be studied as
well as the potential for beneficial impacts due to reduced combustion
at other sources within the area.
The Fairbanks area is also subjected to extended periods of wintertime
ice fog,and the Alaska Department of Environmental Conservation will
require the impact of any water vapor plumes to be carefully assessed.
A combustion turbine power plant which uses water or steam injection
techniques would have an adverse impact on the ice fog and icing
deposition nearby.For the purposes of this study,it is assumed that
Best Available Control Technology would be defined to not include water
or steam injection.
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Construction of the gas pipeline from the North Slope to Fairbanks will
result in fugitive dust and exha~st emissions from construction
vehicles.These air quality impacts will be temporary and located in
very sparsely populated areas,and will therefore be insignificant.
Ten compressor stations will be located along the pipeline route,each
producing relatively low levels of emissions.The impacts of these
facilities will most likely not cause exceedances of the Alaska Ambient
Air Quality Standards and will not be required to meet the Prevention
of Significant Deterioration Increments.The emissions will not impact
any air quality sensitive areas.
4.6.2 Water Resource Effects
The gas-fired combined cycle power plant descrlbed in Section 4.2 will
use approximately 200 gpm of fresh water for boiler make-up,potable
supplies,and miscellaneous uses such as equipment wash-down.Because
ample groundwater exists in the Fairbanks area and because the water
requirements are not particularly large,impacts on water supplies in
the area will not be significant.
Power plant wastes will consist of wash-down water (for cleaning of
equipment),sanitary wastes,boiler blowdown,and demineralizer
regenerant wastes.The wash-down water will be treated for oil and
suspended solids removal.Sanitary wastes will be passed through a
sanitary wastewater treatment facility,and demineralizer wastes will
be treated for pH control.No treatment shoul d be requi red for boi 1er
blowdown.The resultant wastewater stream,up to 200 gpm,will meet
all applicable effluent guidelines and will be discharged to a local
water body with sufficient assimilating capacity.
The gas pipeline from the North Slope to Fairbanks will cross 15 major
streams and rivers,including the Yukon River,and could potentially
impact numerous additional small streams and drainages.The pipeline
will be buried for its entire length;vegetation will be disturbed
within a 50 ft wide strip.Without careful siting and construction
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practices,erosion from exposed areas could cause sedimentation
problems in nearby water bodies.,
To control soil-loss and sUbsequent sedimentation effects,several
.mitigation practices should be used during pipeline construction.
Existing work pads,highways,access roads,airports,material sites,
and disposal sites should be used whenever possible to minimize
vegetation disturbance.Pipeline rights-of-way and access roads should
avoid steep slopes and unstable soils.Hand clearing could be used in
areas where the use of heavy equipment would cause unacceptable levels
of soil erosion.A 50-foot buffer strip of undisturbed land could be
maintained between the pipeline and streams,lakes,and wetlands
wherever possible.Construction equipment should not be operated in
water bodies except where necessary.Where hi gh 1evel s of sediment are
expected from construction activity,settling basins should be
constructed and maintained.All disturbed areas should be left in a
stabilized condition through the use of revegetation and water bars;
culverts and bridges should be removed,and slopes should be restored
to approximately their original contour.
A significant problem with the operation of a chilled,buried pipeline
is the fonmation of aufeis.Aufeis is an ice structure formed by water
overflowing onto a surface and freezing,with subsequent layers fonned
by repeated overflow.Chilled pipe in streams can cause the stream to
freeze to the bottom in the vicinity of the pipe,creating aufeis over
the blockage.A chilled pipe through unfrozen ground can also form a
frost bulb several times larger than the pipe diameter.This frozen
area can block subsurface flow,forcing water to the surface and
causing aufeis.Road cuts can also expose subsurface flow channels,
causing aufeis build-Up over the roadway.The potential for aufeis and
possible effects will require detailed considerations for all
construction areas.
All stream crossing facilities should be designed to withstand the
Pipeline Design Flood as defined for the ANGTS system.Streams should
be stabilized and returned to their original configuration,gradient,
2648B
4-78
----"11--------------------------
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substrate,velocity,and surface flow.Water supplies for compressor
or meter stations should not be taken from fish spawning beds,fish
rearing areas,overwintering areas or waters that directly replenish
those areas during critical periods.
The Yukon River crossing will utilize an existing bridge.The Yukon
River will therefore not be significantly affected by the pipeline.
4.6.3 Aquatic Ecosystem Effects
The Fairbanks power plant will not cause significant impacts to the
aquatic resources.The water supply for the power plant will be
obtai ned from groundwater,and therefore will not affect surface
waterbodies.Discharges from the plant will be treated to meet
effluent guidelines before being released,so that fish habitat should
not be significantly affected.Discharge quantities will be relatively
low,1ess than 200 gpm.
The pipeline from the North Slope to Fairbanks will cross numerous
rivers and creeks,including the Yukon River.Aquatic resource impacts
will include all those discussed for the North Slope scenario (Section
2.5.3),and additional impac~s caused by the chilled pipeline crossing
waterbodies.Several mitigation measures,in addition to those already
discussed,should be implemented to protect the fish habitat affected
by pi pel ine construction and operati on.Stream crossi ngs shoul d be
constructed such that fish passage is not blocked and flow velocity
does not exceed the maximum allowable flow velocity for the fish
species in a given stream.If these criteria cannot be met,a bridge
should be installed.
Chilled pipes in streams should not cause:a)lower stream
temperatures so 'as to alter biological regime of stream;b)slow spring
breakup and del ay offi sh mi grati on;or c)early fall freeze-up whi ch
would affect fish migration.In addition,the temperature of surface
or subsurface water should not be changed significantly by the pipeline
system or by any construction-related activities.
26488
4-79
All mitigation measures designed to reduce sedimentation of water
bodies (discussed in the water resources section)will protect fish
spawning,rearing and overwintering areas.
For the purpose of making recommendations regarding timing of ANGTS
construction activities,the pipeline corridor was divided into three
large geographical regions:Region I,Beaufort Sea to the Continental
Divide of the Brooks Range;Region II,Continental Divide of the Brooks
Range to the Yukon River;and Region III,Yukon River to Fairbanks.In
association with the ANGTS development,the following broad temporal
guidelines were developed for recommendation for each gasline corridor
region based on fish lise habitat (Schmidt et al 1981).These would
also be applicable to a smaller diameter pipeline.
r
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Regi on I
Region II
Regi on III
Region I
Region II
Regi on I II
Regi on I
Regi on II
Regi on III
2648B
1 May-20 Ju ly
15 April-15 July
1 April-15 July
(early breakup streams)
15 April-15 July
(late breakup streams)
20 July-25 August
15 Ju1y-25 August
15 Ju1y-1 September
25 August-1 October
(small streams)
25 August-15 October
(large streams)
25 August-l October
(small streams)
25 August-15 October
(l arge streams)
1 September-l November
4-80
A critical period for most
streams due to the occurrence
of major spring migrations and
spring spawning (primarily
grayl ing).
A sensitive period.Fry of
spring spawning species have
emerged and major fall
emigrations have not yet
begun.Fish are mobile at this
time and can move to avoid or
reduce effects of disturbance.
A critical period for all
streams.Fish must emigrate
from streams tha t do not
provide winter habitat prior
to freeze-up.Major upstream
migrations and spawning of
fall spawning species occurs
in streams that provide over-
wintering habitat.
The Fairbanks power plant will affect terrestrial resources primarily
through habitat disturbance.As discussed in the Report on Facility
Siting and Corridor Selection (Appendix C),potential power plant sites
in the Fairbanks area are located in developed or previously disturbed
areas.The potential for adversely affecting terrestrial habitats is
therefore not considered to be significant.
Region I
Region II
Regi on II I
A preferred period for con-
struction in many streams that
do not provide winter habitat.
These streams generally are dry
or freeze to the bottom during
winter.This is a critical
peri od for fi sh overwi nteri ng
in springs,large rivers,and
1ake s.
1 October-1 May
(small streams)
15 October-1 May
(l arge streams)
15 October-15 Apri 1
(small streams)
1 No vembe r-15 Ap ri 1
(l a rge streams)
1 Novembe r-l Apri 1
(early breakup streams)
1 November-15 Apri 1
(late breakUp streams)
4.6.4 Terrestrial Ecosystem Effects
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Construction of the gas pipeline from the North Slope to Fairbanks will
require total clearing of a 50-foot right-of~ay for the length of the
gasline.In addition,ten lO-acre compressor stations,two 1.5 acre
metering stations and a gas conditioning facility (15 acres)will be
constructed.Construction activities will disrupt terrestrial animals
near the corridor during the 3-year construction period.The pipeline
alignment will avoid the peregrine falcon nest sites near the Franklin
and Sagwon Bluffs,but other raptors may restrict construction schedules
(refer to Appendix C).Special construction measures may be necessar,y in
the areas delineated by the BUM land use plan,as discussed for the North
Slope scenario.Construction activities,especially aircraft traffic,
could disturb Da11 sheep habitat in critical wintering,lambing and
movement areas.These construction-related impacts would be less than 3
years in duration.
Long term terrestrial impacts will result primarily from habitat
elimination.Important moose browsing habitat,such as the willow stand
along Oksrukuyik Creek,should be preserved.The treeline white spruce
,2648B
4-81
...IJiI!iW".••
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stand at the head of Dietrich Valley,which has been nominated for
Ecology Reserve status,should be avoided.The pipeline d"esign should
allow for free passage of caribou and other large animals.
4.6.5 Socioeconomic and Land Use Effects
The potential socioeconomic and land use effects of locating an
electrical generating facility in the vicinity of Fairbanks includes the
temporary impacts related to the influx of workers and pennanent land use
impacts.
The size of the construction work force for the generating facility is
expected to be approximately 200 persons.These generation units will be
constructed duri ng the summer for a bout 4-5 months.
Since the project could draw on the large labor pool of Fairbanks,it can
be expected that the majority of workers will be hired locally.Economic
benefits to the region will not be significant as employment on the
project will be temporary.Any in-migrating work force will have to seek
temporary housing on their own since housing will not be provided at the
project site.The extent of the impacts on the local housing supply will
depend on the vacancy rate for the summer of each year of construction.
As discussed in the Report on Facility Siting and Corridor Select jon
(Appendix C),development of a generating facility on the outskirts of
the Fairbanks area should not engender significant land use conflicts,
since the focus of the final site selection activities will be on areas
which are presently used for industrial development.However,the
long-term staged development of a major electric generating complex will
certainly be a determinant of future land uses in the local area.
Construction activities at the generating plant site will generate
additional worker and construction vehicle traffic loads on the local
road"system.However,disruptions to existing traffic patterns can be
minimized through site selection by utilizing major highways and
26488
4-82
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arterials to the maximum extent possible and by developing a local access
plan and schedule.Depending on'the site selected,new access
requirements will be planned in recognition of local traffic requirements.
For construction of the gas pipeline in the North Slope-Fairbanks
corridor,employees will be housed either at the pump stations or the
penmanent camp facilities that were constructed for the trans-Alaska oil
pipeline.Construction activities will be consistent with the BLM land
use criteria as discussed in Section 2.5.5.
The potential socioeconomic and land use impacts of the transmission
facilities between Fairbanks and Anchorage included in this scenario are
identical to those discussed in Section 2.5.5 for the North Slope
scenario,with the addition of transmission facilities from the Fairbanks
generating site to the power grid.Again,assuming the site is located
on the outskirts of Fairbanks to the southeast,transmission
interconnections can probably expand on existing GVEA rights-of-way with
minimal additional impacts to existing land uses.However,future land
use patterns will be signficantly affected by the presence of the three
parallel 500 kV transmission lines.
26488
4-83
-
,-,
-
5.0 FAIRBANKS POWER GENERATION
LOW LOAD FORECAST
The Fairbanks generation scenario,under the low load forecast,
requires all of the major systems of the medium growth forecast except
that fewer compression stations are required to transport the gas and
fewer units are required to generate electricity.The Fairbanks area
electrical generating station wJll require 3 combined cycle plants,
each consisting of two gas fired combustion turbines paired with two
waste heat recovery boilers,and a steam turbine generator for a
station capacity of 726 MW in 2010.Units will be phased-in by
bringing each combustion turbine on-line individually,followed by the
waste heat recove~boilers and steam turbine generator.Between
Fairbanks and Anchorage,one new 345 kV transmission line and upgrading
of the Healy-Fairbanks and Willow-Anchorage segments of the existing
line will be required.The Fairbanks residential/conmercial,gas
system peak demand at 100 percent penetration of potential market is
49 MMSCFD.
I
Construction of the gas conditioning facilities,gas pipeline,power
generating facilities and transmission systems,is estimated to cost
$4.7 billion.Total annual operation and maintenance costs are
estimated to be $0.4 billion.The present worth of costs excluding
fuel costs is $3.4 billion.Construction costs of the Fairbanks gas
distribution system total $1.5 billion,with total annual operating and
maintenance costs totalling $41 million.The present worth of costs
for this system is $1.0 billion.
5.1 NORTH SLOPE TO FAIRBANKS NATURAL GAS PIPELINE
As explained in Section 4.1,pipeline design proceeded on the basis of
preliminary gas demand calculations.Because the refined demand values
2631B
5-1
did not warrant design changes,certain of the gas demand calculations
differ in the low load forecast as follows:
After refined demand values were available,the results were:-
Pipel ine Desi 9n
(Prelimina~Demand)
Power Generation
Annual Average Demand
Peak Dai ly Demand
Residential/Commercial
Annual Average Demand
Peak Dai ly Demand
Total
Annual Average Demand
Peak Daily Demand
Utility System Design
(Refined Demand)
Power Generation
Peak Da ily Demand
Residential/Commercial
Peak Daily Demand
Total
Peak Daily Demand
Low Load Forecast
(MMSCFD)
108
179
14
40
122
219
Low Load Forecast
(millions of standard cubic feet per day)
130
49
179
For the low load forecast,the refined demand was 40 MMSCFD less than
the preliminary calculation.
5.1.1 Gas Conditioning Plant
The gas conditioning facility required for the low growth scenario will
utilize the SELEXOL phYsical solvent process,as described in Section
4.1.1.The design flowrate will be 230 MMSCFD based on the daily peak
load anticipated for this growth forecast,a pipeline availability of
96.'5 percent and compressor station demands.All other details and
specifications will be as described in Section 4.1.1.
26318
5-2
-
,~
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5.1.2 Pipeline
Similar to the medium forecast design,the pipeline will have an outside
diameter of 22 inches and will follow the same route;the ANGTS
right-of-way.Details regarding pipeline design and route are presented
in section 4.1.2.
The peak daily flowrate,however,requires only three compressor
stations,which wi11,be located at Stations 2,4 and 7 when using the
ANGTS numbering system.The flow conditions anticipated for the-demand
scenario are presented in Figure 5-1.The design of the compressor
stations is indentical to that presented for the medium load forecast.
All other required systems,facilities and support services will also be
the same as those presented in Section 4.1.2.
5.2 POWER PLANT
The scenario for power generation at a Fairbanks site,under the low load
forecast requires three combined cycle plants to satisfy the anticipated
demand in the year 2010.The schedule for unit addition which resulted
from the analyses presented in the Report on System Planning Studies
(Appendix B)is shown in Tabl e 5-1.
The details of plant design and operation are identical to those
described for the medium load case in Section 4.2.Only where there are
variances due to the decreased number of units are specific items
addressed below.
Total operations and maintenance personnel will be less for this scenario
than the medium load case.Ten on duty operations and maintenance
personnel will be required per shift in 1996 when the first gas turbine
begins operation.In the year 2010 when three complete units are
operating,60 on duty personnel will be required per shift.The plant
site will be approximately 90 acres in size and will include all three
units,two switchyards,and a 300 foot buffer zone around the plant.
26318
5-3
»,I J J t }l '}I )
r,;:;]110.1 ".2-~S.1"'1.'~,.,.1 r;;;:-;:.s.~~..
~0
to ~...I!",~~to<it «•••:l.<~;)-~L110o.~-"~~It \'I a:t"0 2a::IlL i Ill.0 ..~(.(~t ~t
....2.MM Se.l"/b ~;)~f
TOtAL 410 M'LES.zz·0.0.PIPELINE.WALL THICKNESS.Q2tlt INCN MINIMUM
STATION DESIGNATIO"II."c.•.,C•••I C••••c...4 C.,••C."•C.,.,C.,••C."•C."10 1'ClWt:.1n.,P"UDHOE ...,
MILEPOST (MILUI 0.0 'lrO.1 /4'.3 2.73.""""0.0
nEYATION(FEET)2.1 'iJ2.,.S'.305'0 '3,S-5"00z
STATION INLET VOLUME (MMSCF 10)22.!'''is'0 2.30 2.~O ~'2.1t=
t!TOTAL FUEL (MMSCFID)-1 1 r -..
'TATION OUTLn VOLUME (MMSCFID)2.:!.O 22.1 2.2.~2.2.7 "S'
ITATION SUCTION PRESSURE (PSlG)/2.'0 /It)l-/03'I''4 10-+'
STATtOte DISCHARGE PRtSSURE (PSlG)1'2.'0 I'2.~"V5 12.'0 -
z 'cOMPRESSOR SUCTION PRlSSURE(PSIG)10'17 /03,"'0 --0
it COMPRESSOR OISCHAROE PRESSUAE ("10)12.,"4-/11'./2&4--..-...
II:COMPRESSION RATIO 1.15'0 1./37 -..I.'SO:I
0 HORSE POW[R R[OUIRI:O ''''''5'"0 .'~70 1'32.0 -u -
ALASKA POWER AUTHORITY-
NORTH SLOPE GAS
FEASIBILITY STUDY
HYDRAUL IC SUi'1f1ARY
LO~I FORECAST
PEAK DAILY FLOH
FIOURE !i-I
,EBASCO SERVICES INCORPORATED
2631B
TABLE 5-1
NEW CAPACITY ADDITIONS AND FUEL REQUIREMENTS
FAIRBANKS POWER GENERATION SCENARIO -LOW LOAD FORECAST!!
5-5
~I
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-
-
-
-
Annual fuel requirements for power generation will grow from 5.96 BCFY
in 1996 to 32.23 BCFY in 2010.The maximum potential firing rate in the
year 2010,based on a heat rate of 8280 Btu/kWh,wi 11 be approximately
9 x 10 4 SCFM.Annual fuel requirements for the study period are also
shown in Table 5-1.
5.3 TRANSMISSION SYSTEM
5.3.1 Fairbanks to Anchorage
This transmission system uses two 345 kV lines as described in
Section 3.2.Other details are similar,inclUding series compensation.
5.4 FAIRBANKS GAS DISTRIBUTION SYSTEM
5.4.1 Fairbanks Residential/Commercial Gas Demand Forecasts
A stUdy has been performed by Alaska Economics Incorporated to forecast
residential and commercial gas demand in Fairbanks.A sUlTll1ary of the
stUdy's methodology and the results of the medium growth projection·
appear in Section 4.4.1.The text of the study appears in Appendix E•
Table 5-2 presents the study's results for the low growth forecast.
These forecasts have been made conditional on the gas achieving the
discrete percentages of the total market for heating and cooking energy
applications shown in Table 5-2.The size of the total market to which
these percentages have been applied has been projected to grow at a 1.43
percent annual average rate,the low growth forecast,beginning in
1981.This rate is the implied population growth rate for Fairbanks as
derived in Battelle's (1982}low forecast of the demand for electricity
in the Railbelt area.
5.4.2 Fairbanks Gas Distribution System.
The gas distribution system has been designed to supply Fairbanks a low
growth demand value of 5.2 BCFY.The differences in flowrates and
service areas between the medium and low growth scenarios affect the
2631.B
5-6
TABLE 5-2
FAIRBANKS RESIDENTIAL/COMMERCIAL GAS DEMAND
LOW GROWTH FORECASTl!
~Del ivered Gas,BCF Per Year
1985 2010
Market growth at 1.43 Percent
10%of Ma rket 0.510 0.727
20%of Market 1.275 1.818
40%of Ma rket 2.039 2.908
iP'"1Oat of Market 5.098 7.720
Del ivered Gas,BCF Per Peak Month
1985 2010
~10%of Market 0.085 0.121
20%of Ma rket 0.212 0.302
4at of Market 0.338 0.483
~10m of Market 0.846 1.207
.-Delivered Gas,BCF Peak Daily
1985 2010
......1 0%of Market 0.003 0.005
2at of Ma rket 0.009 0.012
4at of Market 0.014 0.020
"'"100%of Market 0.034 0.049
-!/Refer to Appendix E for details
2631B
5-7
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size and lengths of the high pressure and distribution system mains.
'The sizes and footages of the hi gh pressure mains and the distri buti on
mains required for the low growth forecast are presented below.All
other system and piping details are the same as the medium growth
forecast which is described in Section 4.4.2.
High Pressure System Mains
S1 ze (Inches)
8
10
12
14
Length (Feet)
6,000
15,000
27,375
7,500
Schedule of Distribution Mains
-
Size (Inches)
2
4
6
5.5 COST ESTIMATES
5.5.1 Capital Costs
Length (Feet)
450,000
78,000
90,750
.-
5.5.1.1 North Slope to Fairbanks Gas Pipeline
Order of magnitude,investment cost estimates have been prepared for
the systems and facil i ti es which compri se the North Slope to Fai rbanks
natural gas pipeline.These estimates are presented in Table 5-3.
5.5.1.2 Power Pl ant
The capital cost of simple cycle combustion turbines and combined cycle
facilities are the same as that presented in Section 4.5 for the medium
load forecast.
26318
5-8
TABLE 5-3
ORDER OF MAGNITUDE INVESTMENT COSTS
NORTH SLOPE TO FAIRBANKS NATURAL GAS PIPELINE
(Millions of January,1982 Dollars)
Description!!
22 in 0.0.Gas Pipeline
Materials Construction Labor 2/
($1000)($1000)
480,000 4,100,000
Total
Di rect Costs
($1000)
4,580,000
-
Compressor Stations - 3 ea
Metering Stations - 2 ea
Valve Stations -28 ea
Engineering &Construction
Management
SUBTOTAL
Gas Conditioning Facility3/
TOTAL
30,300
2,800
2,500
$515,600
25,300
6,000
3,800
$4,135,100
55,600
8,800
-6,300
27,900
$4,678,600
538,300
$5,216,900
-
1/
2/
3/
A 15 percent contingency has been assumed for the entire project and has
been distributed among each of the cost categories shown.Sales/use
taxes and land and land rights expenses have not been included.
Construction camp facilities and services are subsumed in the
Construction Labor cost category.
Factored pricing basis which includes engineering and construction
management.
2631B
5-9
5.5.1.3 Transmission Line Systems
Order of Magnitude investment cost estimates have been prepared for all
required transmission line systems.The results of this analysis are
presented in Table 5-4.The estimate is of one new 345 kV line,700 MW
capacity,with series compensation and an intermediate switching
station,and the reqUired upgrading of the Willow-Anchorage and
Healy-Fairbanks segments of the existing grid.
5.5.1.4 Gas Distribution System
Order of magnitude and investment cost estimates (January 1982 dollars)
have been prepared for the systems and facilities which comprise the
Fairbanks gas distribution system.The results of the analysis are
presented below.A 15 percent contingency has been assumed for the
entire project and has been di stri buted between each cost category.
Sales/use taxes and land and land rights have not been included.
Constructi on Total Di rect
Labor ($1000)Costs ($1000)
Gas Distribution System
Eng i neeri ng and
Construction Management
TOTAL CONSTRUCTION COSTS
Materi al s
($1000)
$11 ,300 $45,200 $56,500
3,390
$59,890
5.5.2 Operating and Maintenance Costs
5.5.2.1 Gas Pipeline and Conditionfng Facility
Annual operating and maintenance costs (January,1982 dollars)for the
gas conditioning facilities are estimated to be as follows:
-
2631B
Item
Sal aries
Maintenance Costs
(Parts and Expendables)
TOTAL
5-10
Annual Costs ($1000)
$1,390
2,100
$3,490
TABLE 5-4
ORDER OF MAGNITUDE INVESTMENT COSTS
FAIRBANKS TO 'ANCHORAGE TRANSMISSION SYSTEM
(Millions of January,1982 Dollars)
..!!The investment costs one new 345 kV line,700 MW capacity with series
compensation and an intermediate switching station,and reflect
upgrading of the Willow-Anchorage and Healy-Fairbanks segments of the
existing grid to 345 kV.
~/Assumes a cost of $40,000 per mi 1e (Ac.res Ameri can Inc.1981).
Conductors and Devices
Energy Management Systems
Steel Towers and Fixtures
SUBTOTAL
Land and Land Ri ghtsY
Engineering and Construction
Management
Total
Constructi on Di rect Costs
Labor ($1000)($1000)
8,414 17,271
30,872 63,830
10,960 23,260
182,083 311,291
53,183 73,232
41,572 41,572
$327,084 $530,456
14,400
37,130
$581,986
8,857
32,958
12,300
129,214
20,049
$203,378
Material s
($1000)De scri pti onl./
TOTAL
C1 eari ng
Switching Stations
Substations
-
....
I
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26318
5-11
,~
~Annual operating and maintenance cost (January 1982 dollars)for the
gas compressor stations and pipeline maintenance activities are
estimated to be as follows:
.....
Item
Salaries
Maintenance Costs
(Parts and Expendables)
TOTAL
5.5.2.2 Power Plant
Annual Costs ($1000)
$2,090
1,750
$3,840
"'"'"
-
.....
Operating and Maintenance Costs for the combined cycle facility at
Fairbanks are estimated to be $0.0040/kWh.These are based on
discussions with operating p1~nt personnel,history of similar units,
EPRI pub1 i shed data and other studi es.
5.5.2.3 Transmission Line Systems
Annual operati ng and mai ntenance costs (January 1982 doll ars)have been
developed for the scenario's required transmission line facilities and
total $8 million per year.These costs should be viewed as an annual
average over the life of the system.Actual O&M costs should be less
initially,and increase with time •
5.5.2.4 Gas Distribution System
Annual operating and maintenance costs (January 1982 dollars)for the
Fairbanks gas distribution system are estimated to be as follows:
2631B
Item
Salaries
Mai ntenance Costs
(Parts and.Expendables)
TOTAL
5-12
Annual Costs ($1000)
$680
270
$950
-
....
I
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'~,
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5.5.3 Fuel Costs
For the economic analyses which follow fuel costs were treated as zero.
This approach permits fuel cost and fuel price escalation to be treated
separately;and makes possible subsequent sensitivity analyses of the
Present Worth of Costs for thi s scenario based upon a range of fuel cost
and cost escalation assumptions.
5.5.4 Total System Costs
5.5.4.1 Cost Allocation Methodology
The methodology that was developed and presented in Section 4.4.4.1 is
equally applicable to the low growth scenario.
5.5.4.2 Total System Costs
Like the Fa i rbanks medium load growth scenari 0,the Fa i rbanks low load
growth scenario involves a complex series of investments in a gas
conditioning facility,a natural gas pipeline,power generation
facilities,and transmission lines.Also,like the previous Fairbanks
scenario,the costs of the the gas conditioning facility and pipeline
must be appo rti oned accordi ng to the fOrnJul ae presented in Section
4.5.4.1.After that apportionment,total annual system costs can be
calculated.
The formulae for conditioning facility and pipeline cost apportionme'nt
are the same regardless of growth;however,the resulting 01 and 0A
values are quite different between the low and medium growth scenarios.
For the low load forecast the 01 value is as follows:
Residential/Commercial Peak =49 MMSCFD
Daily Flow (2010)
Electrical Generation Peak =130 MMSCFD
Daily Flow (2010)
Total Peak Daily Flow (201 0)=179 MMSCFD
°1 =0.73
.....26318
5-13
The 0A values for the Fairbanks low load forecast are presented in
Table 5-5.Significant to note is the fact that in the low load
forecast case,the residential/commercial customers must assume a
higher share of the capital and annual cost burdens of the gas
conditioning and pipeline facilities.
Given the joint systems cost apportionment,the total annual electrical
systems costs can be calculated.Total annual capital costs are
presented in Table 5-6.Total annual O&M costs are presented in
Table 5-7.Total annual costs are then summarized in Table 5-8.
The present worth of costs has been calcul ated for compari son
purposes.The present worth of costs as of"1982,assuming a discount
rate of 3 percent,is $3.4 billion (1982 $)exclusive of fuel costs.
5.5.4.3 Gas Distribution System Costs
The costs attributable to the gas distribution system serving
residential and commercial customers include a portion of the gas
conditioning plant,a portion of the pipeline,and all of those costs
associated with the distribution system within Fairbanks.Again,the
apportionment method discussed in Section 4.5.4.1 is an essential
precursor to the calculation of final total system costs.
Gas distribution costs depend upon calCUlating 1-01 and l-OA
values.These are presented in Table 5-9.Again,it is clear that the
non-electric customers must assume a larger portion of the capital and
operating expenses in the low load growth scenario as compared to the
medium load growth scenario.
~,
Given those apportionment values,the total systems costs for the gas
distribution system can be calculated.Capital and O&M are presented
in Tables 5-10 through 5-11.Total annual systems costs are summarized
in Table 5-12.The present worth of these costs of 1982,assuming a
.-real discount rate of 3 percent,is $1.05 billion,exclusive of any
fuel costs.
26318
5-14
TABLE 5-5
0A VALUES
FAIRBANKS POWER GENERATION -LOW LOAD FORECAST
Resi denti al El ectri cal Total
Calendar Demand Demand Demand
Year (BCFY)(BCFY) (BCFY)°A
1982 o.o.o.NA1/,.-1983 O.o.o.NA
1984 o.o.o.NA
1985 o.o.o.NA
.....1986 o.o.O.NA
1987 O.O.O.NA
1988 O.O.o.NA
1989 o.O.O.NA
1990 o.O.O.NA
1991 O.O.O.NA
1992 O.O.O.NA
1993 O.O.O.NA
1994 O.O.O.NA
1995 O.O.O.N/A
1996 1.266 5.958 7.224 0.82
1997 2.568 11.873 14.441 0.82
1998 3.906 11.873 15.779 0.75
1999 5.283 11.873 17.156 0.69
2000 6.698 11.905 18.603 0.64
2001 6.794 11.939 18.913 0.63
2002 6.891 17.876 24.767 0.72
~2003 6.990 17.876 24.866 0.72
2004 7.090 23.874 30.964 0.77
2005 7.191 23.874 31.065 0.77
2006 7.294 29.814 37.108 0.80
2007 7.398 29.814 37.212 0.80
2008 7.504 33.413 40.917 0.82
2009 7.611 34.508 42.119 0.82
201 0 7.720 32.229 39.949 0.81
II NA -Not applicable
26318
5-15
26318
5-16
TABLE 5-7
ANNUAL NON-FUEL OPERATING AND MAINTENANCE COSTS
FAIRBANKS POWER GENERATION -LOW LOAD FORECAST
(Mill ions of January,1982 Dollars)
Gas
Calendar Transmission Conditioning
Year Electricity Generated Line Pipeline Plant Total
,~1982 o.O.O.o.o.
1983 O.O.o.o.O.
1984 O.O.o.O.o.
1985 O•.O.o.O.O.
~1986 O.O.O.O.O.
1987 O.O.O.O.O.
1988 O.O.O.O.O.
1989 O.O.O.O.O.
1990 O.O.O.O.o.
1991 O.O.O.O.O.
1992 O.O.O.O.O.-1993 O.O.O.O.O.
1994 O.O.O.O.O.
1995 O.O.O.O.O.-1996 2.268 8.00 3.15 2.86 16.3
1997 4.520 8.00 3.15 2.86 18.5
1998 4.520 8.00 2.88 2.62 18.0
~1999 4.520 8.00 2.65 2.41 17.6
2000 4.520 8.00 2.46 2.23 17.2
2001 6.360 8.00 2.42 2.20 19.0
2002 8.620 8.00 2.76 2.51 21.9
.-2003 8.620 8.00 2.76 2.51 21.9
·2004 10.908 8.00 3.00 2.69 24.6
2005 12.720 8.00 3.00 2.69 26.4
I~2006 14.980 8.00 3.07 2.79 28.8
2007 14.980 8.00 3.07 2.79 28.8
2008 16.112 8.00 3.15 2.86 30.1
2009 16.640 8.00-3.15 2.86 30.7 -
""'"201 0 17.168 8.00 3.11 2.83 31.1
Total $147.$120.$44. $40.$351.
,...,.
2631B
5-17
.-
26318
5-18
-
-
26318
TABLE 5-9
APPORTIONMENT VALUES FOR THE GAS DISTRIBUTION SYSTEM
FAIRBANKS POWER GENERATION -LOW LOAD FORECAST
5-19
TABLE 5-10
CAPITAL COSTS ASSOCIATED WITH THE DISTRIBUTION SYSTEM
FAIRBANKS POWER GENERATION -LOW LOAD FORECAST
(Mill ions of January,1982 Do 11 ars)
Gas-Calendar Conditioning Distribution
Year Plant Pipeline System Total
~1982 O.o.o.o.
1983 O.O.O.O.
1984 O.O.O.O.
1985 O.O.O.O.
1986 O.O.O.o.
1987 o.O.o.o.
1988 O.O.O.o.
fJJI!A 1989 O.O.O.O.
1990 O.O..O.O.
1991 O.O.O.O.
1992 O.O.O.O.
1993 O.421.0 12.0 433.0
1994 72.6 421.0 12.0 505.6
1995 72.6 421.0 12.0 505.6
1996 O.O.12.0 12.0
1997 O.O.12.0 12.0
1998 O.O.o.o.
~1999 O.O.O.O.
2000 O.O.O.O.
2001 O.O.O.O.
~Wl'!\2002 O.O.O.O.
2003 O.o.o.O.
2004 O.O.O.O.
2005 O.O.O.O.
2006 O.O.O.o.
2007 O.O.o.O.
2008 O.O.O.O.
2009 O.O.O.O.
2010 O.O.O.O.
Total $145.$1,263.$60.$1,468.
2631B
5-20
TABLE 5-11
OPERATION AND MAINTENANCE COSTS
ASSOCIATED WITH THE DISTRIBUTION SYSTEM
FAIRBANKS POWER GENERATION -LOW LOAD FORECAST
(Millions of January,1982 Dollars)
....Gas
Calendar Co ndi ti oni n9 Distribution
Year Plant Pipeli ne System Total
1982 O.O.O.O.
1983 O.O.O.O.
~1984 O.O.O.O.
1985 O.O.O.O.
1986 O.O.O.O.
1987 O.O.O.O.-1988 O.O.O.O.
1989 O.O.O.O.
1990 O.O.O.O.
1991 O.O.O.O.
1992 O.O.O.O.
1993 O.O.O.O.
--1994 O.O~O.O.
1995 O.O.O.O.
1996 0.63 0.69 0.95 2.3
1997 0.63 0.69 0.95 2.3
1998 0.87 0.96 0.95 2.8
1999 1.08 1.19 0.95 3.2
2000 1.26 1.38 0.95 3.6
2001 1.29 1.42 0.95 3.7
2002 .0.98 1.08 0.95 3.0
2003 0.98 1.08 0.95 3.0
2004 0.80 0.88 0.95 2.6
2005 0.80 0.88 0.95 2.6
2006 0.70 0.17 0.95 2.4
2007 0.70 0.17 0.95 2.4
2008 0.63 0.69 0.95 2.3
2009 0.63 0.69 0.95 2.3
2010 0.66 0.73 0.95 2.3
Total $13. $14.$14.$41.
2631B
5-21
"'"££Lb__".,,_..
26318
5-22
5.6 ENVIRO~'ENTAL AND SOCIOECONa1IC CONSIDERATIONS
The Fairbanks power plant for the low load forecast will consist of three
combined cycle units in contrast to five combined cycle and two simple
cycle units for the medium load forecast.Power plant characteristics
are sUll1Tlari zed in Table 5-13.
It is assumed that water or steam injection would not be required for
NOx control because of associated ice fog problems.Air emissions will
be reduced by approximately one-half from the medium load forecast,and
will meet all applicable air quality standards.Groundwater will provide
approximately 100 gpm"for equipment wash-down,potable supplies,and
boiler make-up water.This relatively small amount of water will not
affect ground water supplies in the area.Wastewater discharges will be
less than 100 gpm and will be treated to meet effluent guidelines.
Aquatic resources,as for the medium load forecast,will not be
si gnifi cantly affected.Pl ant acreage wi 11 be approximately 90 acres,as
compared to 140 acres for the medium load forecast.Terrestrial impacts
on vegetation and habitat elimination are correspondingly reduced.
Pipeline-related impacts are identical to those discussed for the
Fairbanks scenario medium load forecast,Section 4.5.Impacts associated
with the transmission line from Fairbanks to Ancho~age are identical to
those discussed in Section 3.5-for the North Slope scenario,low load
forecast.Socioeconomic impacts are expected to be similar to those for
the medium demand scenario.
Socioeconomic impacts,as for the medium load forecast,are not expected
to be significant.The majority of workers will be hired locally.Any
in-migrating workforce will have to seek temporary housing on their own
but this number is expected to be low.
26318
5-23
.-
.-
-
TABLE 5-13
ENVIRONMENT RELATED POWER PLANT CHARACTERISTICS
FAIRBANKS POWER GENERATION -LOW LOAD FORECAST
COMBINED CYCLE POWER PLANT
Mr Environment
Emissions
-Particulate Matter
Sulfur Dioxide
Nitrogen Oxides
PhYsical Effects
Below standards
Below standards
Emissions variable within standards -
dry control techniques would be used
to meet calculated NO x standard of .
-0.014 percent of total volume of
gaseous emissions.This value
calculated based upon new source
performance standards,facility heat
rate,and unit size.
Maximum structure height of 50 feet
-
-
Water Environment
Plant Water Requirements 100 GPM
.Plant Discharge Quantity,Less than 100 GPM
inclUding treated sanitary
waste,floor drains,
boiler blow-down and
demineralizer wastes
Land [nvi ronment
Land Requi rements
Plant and Switchyard
.-Soci oeconomi c Envi ronment
Constructi on Workforce.
Operating Workforce
""",
-
.2631 B
90 acres
Approximately 100 personnel at peak
construction
Approximately 50 personnel
5-24
--------_._---------_._=---"""""""",---------------.....,..----
-
,-.-
".."
i,
-
6.0 KENAI AREA POWER GENERATION
MEDIUM LOAD FORECAST
The development of power generation facilities in the Kenai area which
will utilize North Slope natural gas is dependent on the construction
of a major,high pressure gas pipeline from the North Slope to a
tidewater location near Kenai.The details concerning this pipeline
and the attendant tidewater gas conditioning and liquefaction
facilities are presented in The Governor's Economic Committee (1983)
report entitled "Trans Alaska Gas System:Economics of an Alternative
for North Slope Na tura1 Gas.II
The gas conditioning and liquefaction facilities associated with the
Trans Alaska Gas System (TAGS)will have numerous power loads,manY of
which can not be satisfied by any source except electricity.These
loads will include lighting,certain types of heating,ventilation and
air conditioning systems,pumps,various process coolers and
compressors,controls,tools,and any shaft horsepower requirements
that are intermittant,such as some refrigeration applications,or too
small to be economical for a combustion turbine.Based on the
electrical demand values required for the ANGTS gas conditioning
facility and discussions with gas liquefaction process equipment
vendors,the total peak electrical demand of these tidewater processing
facilities has been estimated to be approximately 300 MW.This value
is only an approximation,the actual demand requirements will be
dependent upon the type of liquefaction facility selected for design
(e.g.compressor/expander system,Cascade refrigerant system),and
specific design decisions regarding various process power sources made
during detailed engineering.To ensure that the Kenai power generation
scenario presents a realistic development approach and that the entire
Railbelt utility system can support such a major contingency of demand,
the anticipated electrical requirements of these processing facilities
have been included in the el~ctrical demand analysis.As TAGS will be
developed in phases,the total electrical demand of the facilities has
25548
6-1
~.been proportioned.based on the flow rates anticipated during each
phase.
This scenario.then.centers on a major electric generating station in
the Kenai area near the terminus of the TAGS pipeline.By the year
2010.the station would consist of 7 combined cycle units and 1 simple
cycle gas turbine to satisfy the medium energy demand forecast for the
Rai1be1t and the additional power requirements of the TAGS gas
conditioning and liquefaction facilities.a total of 1743 MW.The fuel
for the power plant will be a blend of waste gas from the TAGS gas
conditioning facilities and TAGS sales gas.A major electrical
transmission system from the Kenai generating station to Anchorage is
required.The Kenai to Anchorage lines would be operated at 500 kV and
employ an underwater crossing of Turnagain Arm.To ensure system
reliability.both the 500 kV lines from Kenai to Anchorage and the 345
kV lines from Anchorage to Fairbanks would consist of two parallel
lines.A residential/commercial gas distribution for Fairbanks is not
an integral part of this scenario.although it is not precluded as an
adjunct to TAGS.The total construction cost of this scenario is $2.1
billion.with total operation and maintenance costs of $0.8 billion per
year.The present worth of these costs excluding fuel costs is $2.0
bi 11 ion.
6.1 POWER PLANT
6.1.1 General
The power generation technology selected for the Kenai locale is
combined cycle utilizing 237 MW baseloaded plants (refer to .
Appendix B).The plants are identical in configuration with those
described in Section 4.2.The difference in capacity rating is due to
the slightly higher average annual temperature encountered in the Kenai
~
local e.
25548
6-2
--
-
Facilities required for the site and the site arrangement will be the
same as that described in Section 4.2.Equipment arrangement will be
as previously shown in Figures 4-1 and 4-2 and the site arrangement as
shown in Figure 4-3.A total of 7 complete combined cycle plants plus
1 simple cycle gas turbine will be required to satisfy the demand for
energy in the year 201 O.The 1and a rea requ'j red for thi s development
will be approximately 175 acres.The schedule for addition of these
facilities is shown on Table 6-1 along with the total of new capacity
on a yearly basi s.
The functional parts of the power plant will include all the systems
described in Section 4.2.Additionally,a system for gas quality
monitoring will be necessary.The fuel to be utilized will be a blend
of waste gas ~nd sales gas from the gas conditioning plant (see Section
6.1.4 Fuel Supply).
6.1.2 Combustion Turbine Equipment
The combustion turbines will be identical to those described previously
except for one operating detail.The gas burner nozzle in the
combustion chamber is typically designed to operate at a specific fuel
heat value plus or minus 10 percent.A nozzle purchased to burn 400
Btu/ft3 fuel wi 11 be useful to 440 Btu/ft3•In order to burn
higher Btu content gas,a different nozzle would need to be installed.
Several nozzles for a range of potential fuels should be inventoried
for each turbine.
6.1.3 Steam Plant
The effect of burning a low Btu content fuel on the heat recovery steam
generator (HRSG)will be negligible.Since the gas turbines are
controlled at a constant gas temperature,the response of the system to
a higher flow of noncombustibles in the waste stream will be to reduce
the amount of excess air while maintaining gas temperature and mass
-flow constant.Therefore,no changes to the HRSG or the balance of the
steam cycle from that described in Section 4.2 is expected.
2554B
6-3
TABLE 6-1
NEW CAPACITY ADDITIONS AND FUEL REQUIREMENTS
MEDIUM LOAD FORECAST
KENAI POWER GENERATION
-.,
-
-
6.1.4 Fuel Supply
Depending upon the gas conditioning facility design chosen,a waste gas
stream comprised mainly of carbon dioxide and heavier ~drocarbons may
be generated.It has been previously estimated (refer to Appendices A
and B)that a waste gas stream of approximately 430 MMSCFD with a
higher heating value of 195 Btu/ft3 could result.While it is
possible to directly burn this waste gas in combustion turbines,it
will require expensive redesign of the turbines,and increased
equipment supply costs.Since the waste stream alone could not supply
enough energy to satisfy demand through the year 2010,it was decided
to blend the waste gas with sales gas to achieve a minimum heating
value of 400 Btu/ft3 (HHV).This resultant heating value does not
require combustion turbine modifications.The required amounts of both
waste and sales gas are shown in Table 6-1.
6.1.5 E1 ectrica 1 Equipment and Substation
The electrical equipment,including the generators,will essentially be
the same as that described for the North Slope and Fairbanks medium
forecast scenarios (Sections 2.1 and 4.2).Major differences involve
the number of units installed,their actual ratings,and the bus
voltage.Figure 6-1 presents a simplified one line diagram of the
substation.There will be 22 generators feeding the 11 transformers,
each rated 200 MVA 13.8/115 kV.For this alternative 115 kV bus
voltage was chosen to be compatible with the existing 115 kV Chugach
Electric Association line in the area.Three circuits will provide
power for local area loads.The outgoing voltage will be 500 kV,with
the two lines,each supplied by two 750 MVA transformers,terminating
in Anchorage.Whenever possible,a breaker and a half configuration
will be used.
6.1.6 Other Systems
Depending on interpretation of regulations governing the application of
Best Available Control Technology (BACT),it may be necessary to add an
25548
6-5
1 -i -.])1 i 1 t 5 I _.-._.-J )J .-j -1 J i.
13.&kV
22 22 22 22 22 22 22 22 22 2222
LOCAL
500kV
LOCAL150MVA
TYPICAL
LOCAL
200MVA
TYPICAL
200MVARI~_
TYPICAL 1
LEGE.NDoGENERATOR
~otl,........TRANSFORMER
o C.IRCUIT 8RE'AKER
-'\I\I\r-REACTOR
~CAPACITOJi:
TO ANCHORAGE
r "
TO ANCHORAGE
ALASKA 'OWER AUTHORITY
NORTH .LOPE GA.
'tAI....ITV .TUOY
KENAI POWER GENERATION
MEDIUM LOAD FORECAST
SUBSTATION ONE LINE SCHEMATIC
~I'-f
I.AICO _"VICEI 1NC000000000ATtD
,,.."
,-
'"""
-
NO x control system to the gas turbines at the Kenai location.All
other systems will be identical to those described for the Fairbanks
medium load growth forecast (Section 4.2).
The NOx control system will consist of either steam or water
injection directly into the combustion chamber.This is used to
control the gas temperature,keeping it below the range of high NO x
formati 0 n.
6.2 TRANSMISSION SYSTEMS
6.2.1 Kenai to Anchorage Line
6.2.1.1 Overview of the System
To transmit medium forecast power from Kenai to Anchorage,a 500 kV
transmission alternative was developed and found to be a cost effective
voltage.Two routes were investigated in detail:a 150 mile long land
based route around Turnagain Arm,crossing the mountains west of
Gi rwood to Anchorage;and an underwater cablecrossi ng-of Turnagai n
Arm.The latter route was chosen as the better alternative.A brief
description of the line is presented below.
The line,with its two circuits on separate towers,will originate at
the Kenai generating plant substation and will run eastward to
approximately Sterling.The two circuits will then run towards the
northeast and follow an existing pipeline right-of-way.The overland
route on the Kenai peninsula will be 65 miles in length and will
terminate at Gull Rock.From this point 4 mile-long cables will car~
the power underwater to the north shore of Turnagain Arm to a location
marked Isle 29,which is less than a half-mi1e northwest of McHugh
Creek.The remaining overhead line segment will parallel the
Seward-Anchorage highway for about 25 miles before reaching the
substation at Anchorage.
25548
6-7
-
--
-
-
This routing is made possible by recent advancements in cable
technology developed by Pire11i of Italy and Standard Telefon O.G.
Kabel Fabrik AjS of Norway,which are about to install,for the British
Columbia Hydro and Power Authority,two 500 kV circuits,each
consisting of three single phase cables between the British Columbia
mainland and Vancouver Island.The Turnagain Arm crossing will consist
of 7 cables:3 for each circuit and 1 spare.
The system is similar to the one presented for the North Slope to
Fairbanks connection,except there will be no intermediate switching
stations and there will be a cable crossing.The design of the
overhead section of the line will be identical to the North
Slope-Fairbanks connection described in Section 2.3 and Appendix 0,
except that guyed type transmission towers will be used for this line
and only 3 repeater stations will be required for comnunication
purposes.
6.2.1.2 Alternatives
Several alternative transmission corridors between Kenai and Anchorage
were considered in order to select a reasonable route for cost
estimating purposes.Factors considered were general engineering and
environmental constraints.Of the many potential routes,two were
investigated in detail.A land based route was assumed to follow the
existing Chugach Electric Association (CEA)right-of-way,which
generally follows the Sterling and Seward Highways,and which traverses
the eastern end of Turnagai n Arm.However,closer exami nati on of that
route in 1 i ght of the maj or transmi ss;on faci 1i ty requi rements
disclosed the following severe constraints:
(1)The existing transmission lines between Portage and Indian Creek
are co-located with the Seward Highway and the Alaska Railroad on a
narrow bench between Turnagain Arm and.the Chugach Mountains.The
bench is at the base of a unifonn1y steep slope whi ch ri ses to
above 3500 feet in elevation.The proposed transmission facilities
could not reasonably be accommodated within or adjacent to the
2554B
6-8
-
existing rights-of-way.One option for avoiding this area would be
to traverse the Chugach Mountains between Portage and Anchorage.
This would,however,involve crossing difficult terrain,much of
which is included in the Chugach State Park.
(2)The existing CEA right-of-way parallels the Sterling Highway for
most of its length.In the vicinity of Bear Mountain,designated
wilderness areas within the Kenai National Wildlife Refuge are
within close proximity of the highway.Development of transmission
facilities of the magnitude required by this scenario would
engender severe aesthetic impacts to travelers along this scenic
highway,and possibly infringe on wilderness land use values.
As a consequence of these severe routing constraints,this study
focused on a transmission line corridor which utilizes a Turnagain Arm
crossi ng from Gull Rock to McHugh Creek.The total length of thi s
preferred corridor route is 94 miles,as compared to the 150 mile route
which would be required for a completely overland route around the
eastern end of Turnagain Arm.
6.2.2 Anchorage Substation
The planned Anchorage substation is shown in Figure 6-2.The two
500 kV lines will terminate in two 750 MVA 345/525 kV transformers.
The bus will feed the area transmission system using 138/345 kV
transformers.From the bus two 345 kV lines will connect to
Fairbanks.These lines will have shunt reactors but no series
capacitors connected to them.
6.2.3 Anchorage to Fairbanks Line
This line must carr,y about half the amount of power that the Fairbanks
to Anchorage lines have to carr,y under previously discussed low growth
forecast conditions (Section 3.2).Therefore,one 345 kV line would be
adequate as far as power carrying capability and system performance is
concerned.However,the reliability of electric power transmission
2554B
6-9
-1 J -1 1 I -1 1 1 1 j J )1 1
TO FA IR BANK5
z.oo MVAR
TYPICAL
LOC~L LOCALl/38k1
.1.......,\1\r--i
LOCAL
kvl
-STATIC VAR COMPEN.sATOR
1.38
LEGENDoGENERATOR
~o.n'W\TRANSFORMER
o CIRCUIT 8REAKE~
-"\I\I\r REACTOR
~CAPACIToR
T
TO KENAI
T
ALAIKA 'OWER AUTHORITY
MORTH 1l000£GAl
FU•••..fTY lTUOY
KENAI POWER GENERATION
MEDIUM LOAD FORECAST
ANCHORAGE SUBSTATION ONE
LINE SCHEMATIC
....UIlI e-t
IIAIeO HfmCEllNCOfIPOftATID
f~
over a single line is very poor,making two lines in parallel a minimum
requirement.With two lines,neither series compensation nor an
intermediate switching station is required at 345 kY.Therefore,in
thi s scenari 0,the 345 kY i ntertie will be fully extended and a second
line will be built between Anchorage and Fairbanks using the Gilbert
Commonweal th (l981)des;gn.
6.2.4 Fairbanks Substation
The Fairbanks substation will be the terminus of the two 345 kY lines.
It will be a conventionally designed 345/138 kV substation using a
I"'"breaker and a half sctieme to supply the two 138/345 kV transformers
that will provide power locally.
6.3 COST ESTIMATES
,~
6.3.1 Construction Costs
6.3.1.1 Power Plant
....
To support the derivation of total systems costs which is presented in
Section 6.3.4,order of magnitude investment costs were developed for'
the major bid lines items common to a 77 MW (ISO conditions)natural
.gas fired simple cycle combustion turbine and a 220 MW (ISO conditions)
natural gas fired combined cycle plant.These costs are presented in
Tables 6-2 and 6-3.The costs represent the total investment for the
first unit to be developed at the site.Ad~itiona1 simple cycle units
will have an estimated investment cost of $35,680,000 while additional
combined cycle units will have an estimated investment cost of
$128,060,000.The unit cost differential for addition units is due to
significant reductions in line items 1 and 15,improvements to Site and
Off-Site Facilities,and reductions in Indirect Construction Cost and
Engineering and Construction Management.
25548
6-11
TABLE 6-2
ORDER OF MAGNITUDE I NVESlMENT COSTS
77 MW SIMPLE CYCLE PLANT
KENAI AREA POWER GENERATION -MEDIUM LOAD FORECAST
(January,1982 Dollars)
Descri ption!!
Total
Material Construction Direct Cost
($1000)Labor ($1000)($1000)
-
"""
.....
.....
1-Improvements to Site 475 1,410 1,885
2.Ea rthwork and Pil i ng 75 500 575
3.Circulating Water System 0 0 0
4.Co ncrete 475 2,145 4,505
5.Structural Steel Lifting 1,725 1,370 3,095
Equipment,Stacks
6.Buildings 750 1,440 2,190
7.Turbine Generator 11,400 685 12,085
8.Steam Generator and Accessories 0 0 0
9.Other Mechanical Equipment 955 530 1,485
10.Pi ping 265 590 855
11-Insulation and Lagging 35 135 170
12.Instrumentation 100 70 170
13.Electrical Equipment 1,535 2,665 4,200
14.Painting 70 250 320
15.Off-Site Facilities 300 1,080 1,380
SUBTOTAL $18,160 $12,870 $31,030
Freight Increment 910
TOTAL DIRECT CONSTRUCTION COST $31,940
Indirect Construction-Costs 1,780
SUBTOTAL FOR CONTINGENCIES 33,720
Co nt i n9 e nc ies (l 5%)5,060
TOTAL SPECIFIC CONSTRUCTION COST 38,780
Engineering and Construction 2,200
Management
TOTAL CONSTRUCTION COST $40,980
.!!The following items are not addressed in the plant investment
pri ci ng:1aboratory equipment,switchYard and transmi ssi on
facilities,spare parts,land or land rights,and sales/use taxes •
2554B
6-12
TABLE 6-3
ORDER OF MAGNITUDE I NVESTMENT COSTS
220 MW COMBINED CYCLE PLANT
KENAI AREA POWER GENERATION -MEDIUM LOAD FORECAST
(January,1982 Do 11 ars)
l.Improvements to Site 490 1,440 1,930
2.Ea rthwork and Pi 1i ng 220 1,520 1,740
3.Circulating Water System 0 0 0
4.Concrete 1,485 6,730 8,215
5.Structural Steel Lifti ng 3,800 3,530 7,330
Equipment,Stacks
6.Buildings 1,800 3,600 5,400
7.Turbine Generator 30,700 2,590 33,290
8.Steam Generator and Accessories 9,600 4,320 13,920
9.Other Mechanical Equipment 6,230 3,120 9,350
10.Pi pi ng 1,630 3,055 4,685
1l.Insulation and Lagging 295 720 1,015
12.Instrumentation 1,700 290 1,990
13.Electrical Equipment 4,600 8,785 13,385
14.Painting 200 720 920
15.Off-Site Facilities 300 1,080 1,380
SUBTOTAl $63,050 $41,500 $104,550
Freight Increment 3,150
TOTAL DIRECT CONSTRUCTION COST $107,700
Indi rect Construction Costs 4,310
SUBTOTAL FOR CONTINGENCIES 112,01 0
Conti ngencies (15%)16,800
TOTAL SPECIFIC CONSTRUCTION COST 128,810
Engineering and Construction 6,800
Management
TOTAl CONSTRUCTION COST $135,610
-
I .~
Descri ption!/
Total
Material Construction Di rect Cost
($1000)Labor ($1000)($1000)
1/The following items are not addressed in the plant investment
pricing:laboratory equipment,switchYard and transmission
facilities,spare parts,land or land rights,and sales/use taxes.
2554B
6-13
-
,~
6.3.1.2 Kenai to Anchorage Transmission Line,
Transmission line order-of-magnitude investment cost estimates for the
submarine cable crossing alternative are presented in Table 6-4.These
estimates are based on two 500 kV 1ines of 1400 MW capacity with series
compensation.An order of magnitude investment cost estimate has also
been prepared for the land based route which traverses the eastern end
of Turnagain Arm.These estimates are presented in Table 6-5.As the
submarine cable crossing alternative is preferred,only this estimate
has been used in the derivation of total systems costs (Section 6.3.4).
6.3.1.3 Anchorage to Fairbanks Transmission Line
Order of magnitude investment cost estimat€s have been prepared for the
Anchorage-Fairbanks connection.These estimates which are presented in
Table 6-6 are based on one new 345 kV line without series compensation
and an intermediate switching station.The estimates also reflect
upgrading of the Willow-Anchorage and Healy-Fairbanks segments of the
present Interti e.
6.3.2 Operation and Maintenance Costs
6.3.2.1 Power Plant
The power plant operating and maintenance (O&M)costs were derived to
support the system planning studies (Appendix B).They reflect a
review of figures from previous Railbelt studies,operation of other
utilities,and salary requirements and expendable materials.The O&M
costs for this scenario are estimated to be $0.0040/kWh.
6.3.2.2 Transm;ssion Line Systems
Annual operati ng a nd rna;ntenance costs (January 1982 doll ars)have been
developed for the scenario's required transmission line facilities an~
total $12 million per year.These costs should be viewed as an annual
25548
6-14
TABLE 6-4
ORDER OF MAGNITUDE INVESTMENT COSTS
KENAI TO ANCHORAGE TRANSt>1ISSION SYSTEM
SUBMARINE CABLE CROSSING ALTERNATIVE
(January 1982 Dollars)
~Total
De scri pti onl/
Materi al Constructi on Di rect Cost
($1000)Labor ($1 OOO)($1000)
~
Switching Stations
,-Substations 63,073 43,729 106,802
Energy Management System 11 ,400 9,400 20,800
Steel Towers and Fixtures 112,370 130,909 243,279
,~O.H.Conductors and Devices 12,726 29,919 42,645
Submari ne Cable and Devices 77,900 52,200 130,100
'f fA C1eari ng 4,164 4,164I
SUBTOTAL 277 ,469 270,321 547,790
Land and Land Right~/7,200
~Engineering and Construction
Management 38,290
TOTAL CONSTRUCTION COST $593,280
~"'"!/The investment costs reflect two 500 kV 1ines,1400 MW capacity
with series compensation.A 15 percent contingency has been
assumed for the entire project and has been distributed among each
of the cost categories shown.Sales/use taxes have not been
;ncl uded.
~/Assumes a cost of $40,000 per mile (Acres American Inc.1981).
2554B
6-15
-
TABLE 6-5
ORDER OF MAGNITUDE INVESTMENT COSTS
KENAI TO ANCHORAGE TRANSMISSION SYSTEM
LAND BASED ROUTE ALTERNATIVE
(January 1982 Dollars)
~,Total
De scri pti on!!
Materi al Construction Direct Cost
($1000)Labor ($1000)($1000)-
Switching Stations 0 0 0
~Substations 51,262 35,540 86,802
Energy Management System 11,400 9,400 20,800
~
Steel Towers and Fixtures 265,066 281,477 546,543
.....Conductors and Devices 20,522 48,248 68,770
Cl eari ng 0 6,720 6,72<;1
"....SUBTOTAL 348,250 381,385 729,635
Land and Land Rights61 11,600
-~
Engineering and Construction
Management 51,100
TOTAL CONSTRUCTION COST $792,335
11 The investment costs reflect two 500 kV lines,1400 MW capacity
with series compensation.A 15 percent contingency has been
assumed for the entire project and has been distributed among each
of the cost categories shown.Sales/use taxes have not been
i ncl uded.
2/Assumes a cost of $40,000 per mile (Peres American Inc.1981).
2554B
6-16
~
,
TABLE 6-6
ORDER OF MAGNITVDE INVESTMENT COSTS
ANCHORAGE TO FAIRBANKS TRANSMISSION SYSTEM
(January 1982 Dollars)
Total
~Materi al Construction Di rect Cost
Description.!.!($1000)Labor ($1000)($1000)
Switching Stations
F*'Substations 38,531 32,100 70,631
Energy Management System 12,300 10,960 23,260
~Steel Towers and Fixtures 129,214 182,091 311,305
Conductors and Devices 20,049 53,183 73,232
r"
Cl eari ng 41,572 41,572
SUBTOTAL 200,094 319,906 520,000
Land and Land Ri ghtsY 14,400
Engineeri ng and Construction
Management 36,400
r TOTAL CONSTRUCTION COST $570,800
1/The investment costs reflect one new 345 kV line without series
compensation or an intermediate switching station,and the
upgrading of the Willow-Anchorage and Healy-Fairbanks segments of
the Intertie to 345 kV..
!/Assumes a cost of $40,000 per mile (kres American Inc.1981).
25548
6-17
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average over the life of the system.Actual O&M costs should be less
initially,and will increase with time.
6.3.3 Fuel Costs
For the economic analyses which follow fuel costs werre treated as
zero.This approach penmits fuel cost and fuel price escalation to be
treated separately;and makes possible subsequent sensitivity analyses
of the Present Worth of Costs for this scenario based upon a range of
fuel cost and cost escal ati on assumpti ons.
6.3.4 Total Systems Costs
Total systems costs for Kenai reflect a very different situation than
the North Slope or Fairbanks scenarios.The Kenai medium growth
scenario recognizes that a pipeline and gas conditioning facility are
required;however,these capital investments are external to the
electricity generation system per see The costs of the pipeline and
the gas conditioning facility should be reflected in the purchase price
of the natural gas rather than in the capital or O&M outl~s.
The methodology and assumptions utilized to derive the systems'costs
which are presented below have been previously described in the Report
on Systems Planning Studies (Appendix B).This methodology is
consistent with previous studies of electric generating scenarios for
the Rai1be1t,specifically Acres American,Inc.(l98l},Susitna
Hydroelectric Project Feasibility Report and Battelle (1982),Railbelt
Electric Power Alternative Study.
The total systems costs for the Kenai medium growth scenario have been
calculated.Annual capital outlays are presented in Table 6-7.Annual
O&M costs are presented in Table 6-8.Total annual costs are
surmnarized in Table 6-9.The present worth of these costs,exclusive
of fuel costs,is $2.0 billion as of 1982,assuming a discount rate of
3 percent and a value base of 1982 dollars.
25548
6-18
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TABLE 6-7
ANNUAL CAPITAL EXPENDITURES
KENAI AREA POWER GENERATION -MEDIUM LOAD FORECAST
(Millions of January,1982 Dollars)
Electricity Generated!!
-
Calendar Transmission
Year Unit A Unit B Line Total
1982 o.O.O.o.
1983 O.O.o.O.
1984 O.·0.O.O.
1985 O.2/O.621.2 621.2
1986 O.O.142.8 142.8
1987 10.6 O.282.2 292.8
1988 35.68 O.114.9 150.6
1989 35.68 O.O.35.7
1990 O.O.O.O.
1991 53.65 71.36 o.125.0
1992 O.O.O.O.
1993 53.65 O.O.53.7
1994 35.68 O.O.35.7
1995 35.68 O.O.35.7
1996 53.65 35.68 O.89.3
1997 35.68 o.O.35.7
1998 O.O.O.O.
1999 53.65 O.O.53.7r2000O.O.O.O.
2001 35.68 35.68 o.71.4
2002 o.o.o.o.
2003 53.65 o.o.53.7
2004 35.68 35.68 o.71.4
2005 .53.65 o.o.53.7
2006 35.68 o.o.35.7
2007 35.68 53.65 o.89.3
2008 35.68 o.o.35.7
2009 o.o.o.o.
201 0 o.o.o.o.
Total $689.$232.$1,161.$2,083.
1/Unit A refers to first unit built in a given year and Unit B to
second unit built.
2/Includes site preparation activities for multiple unit site.
r 25548
6-19
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25548
TABLE 6-8
ANNUAL NON-FUEL OPERATING AND MAINTENANCE COSTS
KENAI AREA POWER GENERA nON -t4EDI UM LOAD FORECAST
(Millions of January,1982 Dollars)
6-20
TABLE 6-9
TOTAL ·ANNUAL COSTS
KENAI AREA POWER GENERATION -MEDIUM LOAD FORECAST
(Millions of January,1982 Dollars)
Calendar Capital o &M Total
Year Expendi tu res Costs Expend i tu re s
1982 O.O.o.
1983 o.O.o.
1984 O.O.O.
1985 621.2 O.621.2
1986 142.8 O.142.8
1987 292.8 o.292.8
1988 150.6 O.150.6
1989 35.7 14.21 49.91
1990 O.16.42 16.42
1991 125.0 16.42 141.42
1992 O.22.64 22.64
1993 53.7 22.64 76.34
1994 35.7 24.46 60.16
1995 35.7 26.66 62.36
1996 89.3 28.87 118.17
1997 35.7 32.89 68.59
1998 O.35.10 35.10
1999 53.7 35.10 88.80
2000 O.36.91 36.91
2001 71.4 36.91 108.31
2002 o.41.33 41.33
2003 53.7 41.33 95.03
2004 71.4 43.14 114.54
2005 53.7 45.64 99.34
2006 35.7 46.72 82.42
2007 89.3 47.81 137.11
2008 35.7 48.90 84.60
2009 O.49.99 49.99
2010 O.51.08 51.08
Total $2,083.$765.$2,848.
Present
Worth @ 3%$1,612.$436.$2,048.
2554B
6-21
~,_-......."""""'--,_-_---------------F"-*-------------,..----
TABLE 6-10
ENVIRONMENT RELATED POWER PLANT CHARACTERISTICS
NATURAL GAS COMBINED CYCLE
KENAI AREA POWER GENERATION -MEDIUM LOAD FORECAST
Air Environment
Emissions
Particulate Matter
Sulfur Dioxide
Ni trogen Ox ides
Ph,ysi cal Effects
Water Environment
Pl ant Water Requi rements
Water Injection
Other Requirements
Plant Discharge Requirements
Oemi neral i zer
Steam Generators
Treated Sanitary Waste
Floor Drains
Land Envi ronment
Land Requirements
Socioeconomic Environment
Construction Workforce
Operating Workforce
2554B
Below standards
Below standards
Emissions variable within standards
-dry control techniques would be
used to meet calculatedNOxstandardof0.014 percent of total
volume of gase~us emissions.This
value calculated based upon new
source perfonnance standards,
facility heat rate,and unit size.
maximum structure height of 50 feet
800 GPM
200 GPM
40 GPM
70 GPM
15 GPM
25 GPM
175 acres
Approximately 200 personnel at peak
construction
Approximately 150 employed personnel
6-22
6.4 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS
The Kenai power plant and transmission line to Anchorage and Fairbanks
will have many environmental effects similar to those discussed for the
North Slope and Fairbanks scenarios.The environmental and
socioeconomic considerations associated with the transmission line from
Anchorage to Fairbanks will be identical to those discussed in Section
3.5,the North Slope Scenario (low load forecast),and therefore will
not be repeated here.Power plant characteristics related to
environmental impacts are summarized in Table 6-10.
6.4.1 Air Resource Effects
J~s is typical of many exposed coastal locations,the air quality and
meteorological conditions are generally favorable to the development of
facilities such as power plants.It is not likely that an intense
Ilmarine layer1
\which may restrict dispersion of pollutants,develops
in this area.The air quality attains the applicable ambient
standards,but the locale is burdened with several existing petroleum
refinery emissions.A new natural gas-fired power plant could probably
be sited in the area with the use of appropriate emissions controls
including water or steam injection to reduce nitrogen oxides
emi ssi ons.The impact of water vapor emi ssi ons on the fonnation of fog
must also be considered.The power plant must be carefully sited in
order to avoid adding to the air quality impacts of the existing
facilities.
Construction of the transmission line from Kenai to Anchorage will
r-esul t in temporary air quality impacts.Heavy equipment and
c:onstruction vehicles will cause fugitive dust and exhaust emissions,
and slash burning will cause particulate emissions.As discussed in
Section 2.5,these emissions would occur rarely and ,would be widely
di spersed ,generally in unpopul ated areas.Long term impacts woul d be
T1legl igible.
2554B
6-23
6.4.2 Water Resource Effects
As in the Fairbanks scenario,water resource effects will be minimal.
Groundwater will supply up to 1000 gpm for water or steam injection
(for control of nitrogen oxides emissions),boiler make-up,potable
s~pplies and miscellaneous uses.Wastewater discharges will consist of
boiler blowdown,demineralizer regenerant wastes and sanitary wastes,
each treated within the plant to meet the appropriate effluent
gui del i nes.Because water used for water or steam i njecti on is
consumed rather than recycled,wastewater quantities will be less than
200 gpm.
The transmission line from Kenai to Anchorage would cross the streams
and creeks listed below.
r
Soldatna Creek
Mystery Creek
Big Indian Creek
Potter Creek
Campbell Creek
Ship Creek
Moose River
Chickaloon River
Little Indian Creek
Furrow Creek
Che ster Creek
The water quality of these streams should not be directly affected if
towers wi 11 be set back from the streambank at 1east 200 feet,and
construction activities stay out of stream channels.Indirect impacts
on the waterbodies,however,will result from construction activity in
the small drainageways that feed the main channel,primarily from
removal of vegetation {causi ng hi gher erosion rates},equipment
crossings of small drainages,and access roads construction.Because
helicopter construction will be used along most of the route,the use
of heaV,Y equipment,vegetation removal,and access road construction
should be minimal.
The transmission line will cross Turnagain Arm from Gull Rock to the
mouth of McHugh Creek via seven buried submarine cables.Construction
phase impacts will consist of increased turbidity from the cable
25548
6-24
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installation»and construction activity near the shore on both
shorelines.Operation phase impacts will primarily be the potential
for cable rupture and 'subsequent cable oil contamination of Turnagain
Arm.The cable will be designed to have a ve~low probability of
rupture over the life of the project.A synthetic cable oil»Dodeco
Benzene»should be used for cable insulation.If this oil accidentally
leaks»it will rise to the surface and quickly evaporate when exposed
to air.This oil is used specifically to minimize environmental
effects associated with a cable rupture.
6.4.3 Aquatic Ecosystem Effects
Because groundwater will provide the power plant's water supply,and
wastewater discharges will be low»the power plant in Kenai will not
significantly affect aquatic resources.
Soldatna Creek and Moose River flow into the Kenai River System,a
major river for anadromous fish habitat.Sodatna Creek provides
spawni ng and reari ng habitat for Sil ver Salmon,and Moose Ri ver
contains King,Silver,and Sockeye Salmon (U.S.Army Corps of Engineers
1978).Sedimentation of these water bodies»as discussed in the
previous section,could affect spawning and rearing habitat in these
streams.Because helicopter construction will be used for most of the
route»however»sedimentation effects would be relatively minor.
Impacts to freshwater aquatic resources will be mitigated primarily
through the control of sedimentation of waterbodies,keeping
construction equipment out of streambeds and wetlands»and avoiding
areas of high biological value.These mitigation measures are
discussed in greater detail in Section 2.5.3 for the North Slope
scenari o.
Crossing Turnagain Arm with underwater cables poses additional
environmental hazards.Turnagain Arm is an environmentally sensitive,
area in the general vicinity of the project that contains marine
mammals,inclUding Harbor Seals»sea lions and Beluga whales (U.S.
25548
6-25
Department of Commen:e 1979).Salmon are present in some of the small
streams that enter this area (Alaska Department of Fish and Game 1978).
Installation of buried,submarine cables will temporarily disrupt the
sea floor along the cable route and increase turbidity and suspended
solids in the vicinity of the crossing.Tidal currents could carry
suspended sediment beyond the immediate crossi ng site.Special
construction techniques should be used to minimize disturbance of the
substrate.Installation should take place when biological activity is
at its lowest point in the yearly cycle.
An accidental rupture of a cable would leak cable oil into the aquatic
environment.As discussed in the previous section,the cable oil used,
Dodeco Benzene,was chosen because it evaporates when exposed to air,
thereby minimizi ng envi ronmenta1 impacts.
The cables m~operate at a temperature level above ambient
conditions.Because the cables will be buried six to ten feet,only
the substrate temperature and not water temperature would be elevated
(Bonneville Power Administration 1981).
6.4.4 Terrestri a1 Ecosystem Effects
Because the Kenai power plant will be located in an area already
extensively developed,1itt1e habitat degradation will occur.The area
di sturbed for power p1 ant constructi on,approximately 140 acres,wi 11
not significantly affect terrestrial resources in the area.
The transmission route passes through an area of caribou habitat
northeast of Kenai (University of Alaska 1974).Little alteration of
caribou habitat will resu1 t from construction of the transmi ssion 1ine
because the animal utilizes cover types that require little if anY
c1 eari ng.
25548
6-26
Much of the route between Kenai and Anchorage is within moose
rangeland.However,because moose utilize manY different habitat
types,they will be the least adversely affected by habitat alterations
(Spencer and Chatelain 1953).Where the proposed route crosses heavily
forested areas,moose will benefit from additional clearing of the
ri ght-of-way and the sUbsequent estab1 i shment of a subc1 imax cOl111lunity
(Leopo1 d and Dar1 i ng 1953).The route does not cross Dall sheep or
mountain goat habitat.
The transmission line corridor passes near Chickaloon Flats and Potter
Marsh on Turnagai n Ann,both key waterfowl areas.Various puddl e
ducks,geese and sandhi 11 cranes feed and rest duri ng seasonal
migration periods in these areas.The shoreline of Turnagain Arm is
also used by seals and sea lions.The transmission line would not
directly affect this wildlife habitat.
Construction of the submarine cable could slightly affect terrestrial
habitat indirectly by increasing turbidity of Turnagain Arm and thereby
affecting food sources.This would be a temporary effect during the
construction phase only.
The transmi s5i on corri dor passes through several vegetati on types.
Between Kenai and Sterling,the vegetation is primarily bottomland
spruce-pop1 ar forest.As the corri dor extends northeasterly towards
Turnagain Arm,the vegetation becomes upland spruce-hardwood forest
and,on the foothills of the Kenai Mountains,coastal western
hemlock-Sitka spruce forest.North of Turnagain Ann,the vegetation is
primarily bottomland spruce-poplar forest (University of Alaska 1974).
Transmission line construction will necessitate clearing a 220-foot
wide corridor in all forested areas.Over the length of the corridor,
it is assumed that a total of 550 acres would be cleared within the
ri ght-of-way.
2554B
6-27
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6.4.5 Socioeconomic and Land Use Effects
The socioeconomic effects of locating a gas conditioning facility and
electrical generating plant depends primarily on the size of the
in-migrating work force.Land use impacts are not expected to occur as
these facilities are compatible with the heavily industrialized
development that dominates the Kenai-Nikiski area.
The size of the construction work force for the generating facility is
expected to be approximately 175 persons.The construction schedule
would require that a unit be constructed every year during the period
1993-2010,with the exception of 1994 and 1999,when no new units would
be required.The duration and time of the construction period would be
4 to 5 months in the summer.
'The extent to which local people would be hired would depend on the
match of ski 11 s requi red for the project to those ski 11 s of the
available labor force.Labor union policies would also influence the
extent of local hi res on the project.The i n-m~grat'i ng work force
would have to seek temporary housing on their own since housing would
not be provided at the project site.The magnitude of the impacts on
the local housing supply would depend on the vacancy rate for the..
summer of each year a uni t was constructed.
The project is expected to have 1itt1e effect on the unemployment rate
since employment on the project would be seasonal.In addition,these
job openings would be competitive with other employment opportunities
in seasonal industries such as construction and fisheries.
The operations work fon:e is expected to be approximately 100.The
magnitude of potential impacts depends on the availability of local
labor to meet the work force requirements.If the majority of the
employees migrate to the Kenai-Nikiski region,the demand for housing
could exceed the supply.
2554B
6-28
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Construction of the transmission lines between Kenai and Anchorage is
expected to take 22 months.The peak work force is estimated at 221
persons during the last 6 months>and average construction work force is
expected to be approx'imately 163 workers.It ; s assumed that workers
would be hi~d from the labor pools of Kenai and Anchorage.
25548
6-29
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7.0 KENAI AREA POWER GENERATION
LOW LOAD FORECAST
The Kenai area power generation scenario,under the low load forecast,
is also depedent upon the development of TAGS.The anticipated
electrical requirements associated with TAGS gas conditioning and
liquefaction facilities have also been included in the electrical
demand analysis.The development scheme will consist of 4 combined
cycle plants and 2 simple cycle combustion turbines conditioning
facility.Fuel for the power plant will be a blend of waste gas and
sales gas.A reliable electrical transmission system will require
parallel lines from the Kenai area to Anchorage (at 500 IcV and
underwater across Turnagain Arm)and from Anchorage to Fairbanks (at
345 IcV).A residential/commercial gas distribution system is not a
part of the scenario.Construction costs for this scenario are
$1.7 billion,with total operation and maintenance costs of
$0.6 billion.The present worth of these costs excluding fuel costs is
$1.7 billion.
The information in this section is intended to include only those
conditions which are significantlY different from those for the medium
load forecast presented in Section 6.0.
7.1 POWER PLANT
This scenario will require four complete combined cycle plants,each
capable of generating 237 MW and two simple cycle combustion turbines,
to sati sfy the low load forecast demand for energy in the year 201 O.
rj 'llie first gas turbine unit will go on line in 1990.The scheduled
additions are summarized in Table 7-1 and details are addressed in
Appendix 8.Fuel requirements for this scenario are also shown in
Table 7-1.
25938
7-1
TABLE 7-1
NEW CAPACITY ADDITIONS AND FUEL REQUIREMENTS
KENAI AREA POWER GENERATION -LOW LOAD FORECAST
New Capacity (MW)Gas Requirements (MMSCFD)l/
Year (Increment/Total)Waste Gas Sales Gas
1990 84/84 12,451.6 3,625.4
1991 0/84 12,451.6 3,625.4
1992 153/237 24,962.1 7,267.8
1993 0/237 24,962.1 7,267.8
1994 84/321 37,413.5 10,893.2
1995 84/405 49,864.6 14,518.3
1996 0/405 49,864.6 14,518.3
1997 153/558 62,372.7 18,160.2
1998 0/558 62,372.7 18,160.2
1999 0/558 62,372.7 18,160.2
2000 0/558 62,372.7 18,160.2
2001 84/642 74,827.0 21,689.7
2002 69/711 74,886.2 21,803.5
2003 0/711 74,886.2 21,803.5
2004 84/795 87,336.2 25,428.4
2005 84/879 99,786.8 29,053.5
2006 69/948 99,848.2 29,071.4
2007 0/948 99,848.2 29,071.4
200.8 84/1 032 11 0,241.2 32,097.3
2009 0/1 032 95,864.8 27,911.6
2010 84/1116 117,735.7 34,279.4
.11 Values as calculated are shown for reproducibility only,and do
not imply accuracy beyond a 100 MMSCFD level.'
2593B
7-2
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Facilities required for the site and the site arrangement will be the same
as that described in Section 4.2.Equipment arrangement will be as
previously shown in Figures 4-1 and 4-2 and the site arrangement as shown
in Figure 4-3.The land area required for this development will be
approximately 120 acres.
The one line schematic of the low forecast generation plant substation is
shown in Figure 7-1.It is essentially a scaled down version of Figure
6-1.The number of generators is reduced to 14 and only one transformer
will supply each of the 500 kV lines,which will be without series
compensa ti on.
7.2 TRANSMISSION SYSTEM
The Kenai~Anchorage transmission system will be similar to the medium
forecast design including the utilization of 7 cables:3 for each circuit
and 1 spare (Section 6.2).Series compensation is not required,however,
because the power transmitted to Anchorage in this low forecast case will
be much reduced from that of the medium forecast.
Installing a reduced number of cables under Turnagain Ann was investigated
but was not considered feasible because it is unlikely that the required
switc~ards could be located at the two terminations due to the lack of
suitable land.During the system studies performed for this project.the
possibility of transmitting the power on two 230 kV circuits,with one
intermediate SWitching station,was also considered.Complete
investigation of this system would have required detailed studies far
beyond the scope of this project.However,such an alternative should be
investigated during detailed engineering.
At the substation in Anchorage the 500 kV voltage will be transformed to
345 kV for transmittal to Fairbanks and to supply local Anchorage loads.
The one line diagram would be similar to that presented in Figure 6-1,
except that there will only be two 750 kVA transformers at the substation
iind the 500 kV lines will not be series compensated.The Fairbanks
liubstation will terminate the two 345 kV ci rcuits and supply,vi a
transformers.the local area load at 138 kV.
25938
7-3
2 2 2 238k2S?2 2 2 2 2 2 2:2100NV",
lVPICAl
LOCAL
III--'VV\,-f
LoCAL
750MVA
.TYPICAL
500KV
LOCAL
200 MVA~TYPICAL
1-..I1AJ\-JII
----,--~1 1
TO ANCHORAGE
LEGENDoGENERATOR
=o.~TRANSFORMERoC/I(CUIT BRE'AJ<ER
-I\JV\r REACTOR
~CAPACITOR
TO ANCHORAGE
ALAIKA 'OWE"AUTHOIlITY
NORTH lLePl GAl
nAI_un lTUDY
KENAI POWER GENERATION
LOW LOAD FORECAST.
SUBSTATION ONE LINE aCHEMATlC
'1eU'lI 7-1
I.AICO IEfMCISICOAPORATtD
--------,
7.3 COST ESTIMATES
7.3.1 Construction Costs
7.3.1.1 Power Plant
The capital cost of simple cycle combustion turbines and combined cycle
facilities are the same as that presented in Section 6.3 for the medium
load forecast.,
7.3.1.2 Transmission Line Systems
Order-of-magnitude investment cost estimates for the submarine cable
crossing alternative for the Kenai-Anchorage line are presented in
Table 7-2.These estimates are based on two 500 kV 1ines of 700 MW
capacity without series compensation.An order-of-magnitude investment
cost estimate has al so been prepared for the 1and based route which
traverses the eastern end of Turnagain Arm.These estimates are
presented in Table 7-3.As the submarine cable crossing alternative is
preferred,only this estimate has been used in the derivation of total
systems costs (Section 7.3.4).
The construction costs associated with the Anchorage-Fairbanks line are
the same for both the medi um and low growth forecasts.These costs
were previously presented in Table 6-6.
~7.3.2 Operation and Maintenance Costs
Power plant operating and maintenance.(O&M)costs are the same for both
the medium and low load forecasts,$O.0040/kWh.Transmission line DaM
costs are estimated to be $12 million per year.These costs should be
viewed as an annual average over the life of the system.Actual O&M
costs should be less initially and will increase with time.
2593B
7-5
TABLE 7-2
ORDER OF MAGNITUDE I NVESlMENT COSTS
KENAI TO ANCHORAGE TRANSMISSION SYSTEM
SUBMARINE CABLE CROSSING ALTERNATIVE
(January 1982 Dollars)
1/The investment costs reflect two 500 kV lines,700 MW capacity
with no series compensation.A 15 percent contingency has been
assumed for the entire project and has been distributed among each
of the cost categories shown.Sales/use taxes have not been
i nc1 uded.
Y Assumes a cost of $40,000 per mile (Peres American Inc.1981).
25938
7-6
_____________------F--·r-r---~-----------------
-TABLE 7-3
ORDER OF MAGNITUDE INVESTMENT COSTS
KENAI TO ANCHORAGE TRANSMISSION SYSTEM
LAND BASED ROUTE ALTERNATIVE
(January 1982 Doll ars)
Total
Materi al Constructi on Di rect Cost
Descriptionl!($1000)Labor ($1000)($1000)
Switching Stations
Su bsta ti ons 30,140 22,366 52,506
Energy Management System 11,400 9,400 20,800
r Steel Towers and Fixtures 265,066 281,477 546,543
I
Conductors and Devices 20,522 48,248 68,770
Cl eari ng 6,720 6,720
SUBTOTAL 327,128 368,211 695,339
Land and Land Rights£!11,600
r Engineering and Construction
:IMa nagement 48,700
TOTAL CONSTRUCTION COST $755,639
2/
The investment costs reflect two 500 kV lines,700 MW capacity
with no series compensation.A 15 percent contingency has been
assumed for the entire project and has been distributed among each
of the cost categories shown.Sales/use taxes have not been
included.
Assumes a cost of $40,000 per mile (Acres American Inc.1981).
2593B
7-7
.....
7.3.3 Fuel COsts
For the economic analyses which follow fuel costs were treated as
zero.This approach permits fuel cost and fuel price escalation to be
treated separately;and makes possible subsequent sensitivity analyses
of the Present Worth of Costs for thi s scenari 0 based upon a range of
fuel cost and cost escalation assumptions.
7.3.4 Total Systems Costs
Total systems costs for the Kenai low load growth scenario are
constructed in a manner identical to that used for the Kenai medium
load growth scenario,except for the number of power plants installed
and operated.
The methodology and assumptions utilized to derive the systems'costs
which are presented below have been previously described in the Report
on Systems Planning Studies (Appendix B).This methodology is
consistent with previous studies of electric generating scenarios for
the Railbelt,specifically Acres American,Inc.(1981),Susitna
HYdroelectric Project Feasibilty Report and Battelle (1982),Railbelt
Electric Power Alternatives Study.
Annual capital expenditures are presented in Table 7-4.Annual O&M
costs are presented in Table 7-5.The summary of all annual costs is
presented in Table 7-6.For comparison purposes the 1982 present worth
of costs,assuming a discount rate of 3 percent and excluding fuel
costs,is $1.7 billion (1982 dollars).
7.4 ENVIRONMENTAL AND SOCIOECONOMIC CONSIDERATIONS
The Kenai power plant for the low load forecast will consist of three
combined cycle units,in contrast to the five combined cycle and two
simple cycle units for the medium load forecast.Power plant
characteristics realted to environmental resources are summarized in
Table 7-7.
25938
7-8
-_"Im_'''''-,_....\1ll1<t ---w__p _
TABLE 7-4
ANNUAL CAPITAL EXPENDITURES
KENAI AREA POWER GENERATION -LOW LOAD FORECAST
(Millions of January,1982 Dollars)
Calendar Electricity Generated Transmission
Year Unit A Unit B Line Total
1982 O.o.o.o.
1983 o.o.o.O.
1984 O.o.o.o.
1985 o.o.o.o.
1986 O.o.603.2 603.2
1987 o.o.138.6 138.6
1988 10.60 o.274.0 284.6
1989 35.68 o.111.6 147.3
1990 o.O.O.O.
1991 35.68 53.65 .o.89.33
1992 O.o.o.o.
1993 35.68 O.O.35.7
1994 35.68 O.O.35.7
1995 O.o.o.o.
1996 53.65 35.68 o.89.3
1997 o.o.o.O.
1998 o.o.o.o.
1999 o.o.o.o.
2000 35.68 o.o.35.7
2001 53.65 o.o.53.7
2002 o.o.o.o.
2003 35.68 o.O.35.7
2004 35.68 o..o.35.7
2005 .53.65 o.o.53.7
2006 o.o.o.o.
2007 35.68 o.o.35.7
2008 o.o.o.O.
2009 35.68 o.o.35.7
201 0 o.o.o.o.
Total $405.$89.$1,128.$1,710.
25938
7-9
i""'-
TABLE 7-5
ANNUAL NON-FUEL OPERATING AND MAINTENANCE COSTS
KENAI AREA POWER GENERATION -LOW LOAD FORECAST
(Millions of Janua~.1982 Dollars)
Ii.......
Calendar Electricity Transmission
Year Generated Line Total
1982 O.O.O.
1983 O.O.O.
1984 O.O.O.
1985 O.O.O.
1986 O.O.O.r 1987 O.O.O.
I 1988 O.O.O.
1989 O.O.O.
1990 2.21 12.0 14.21
1991 2.21 12.0 14.21
1992 6.23 12.0 18.23
1993 6.23 12.0 18.23
1994 8.44 12.0 20.44
1995 10.64 12.0 22.64
1996 10.64 12.0 22.64
1997 14.66 12.0 26.66
1998 14.66 12.0 26.66
1999 14.66 12.0 26.66r200014.66 12.0 26.66
2001 16.87 12.0 28.87
2002 18.68 12.0 30.68
2003 18.68 12.0 30.68
T 2004 20.89 12.0 32.89
2005 23.10 12.0 35.10
2006 24.91 12.0 36.91
2007 24.91 12.0·36.91
2008 26.62 12.0 38.62
2009 23.15 12.0 35.15
201 a 27.68 12.0 39.68
Total $331.$252.$583.
T
T
I'25938
7-10
--------~·_----·---------"-----i------------------
-TABLE 7-6
TOTAL ANNUAL COSTS
,~KENAI AREA POWER GENERATION -LOW LOAD FORECAST
(Millions of Januar,y,1982 Dollars)
~
Ca 1endar Capital o &M Total
.-Year Expenditures Costs Expenditures
1982 O.o.O.
1983 O.O.O.
1984 O.O.O.
1985 O.O.O.r 1986 603.2 O.603.2
1987 138.6 O.138.6
I 1988 284.6 O.284.6
1989 147.3 O.147.3
1990 O.14.21 14.21
1991 89.3 14.21 103.51
1992 o.18.23 18.23
1993 35.7 18.23 53.93
1994 35.7 20.44 56.14
1995 O.22.64 22.64
1996 89.3 22.64 111.92
1997 O..26.66 26.66
1998 O.26.66 26.66
1999 O.26.66 26.66
2000 35.7 26.66 62.36
2001 53.7.28.87 82.57
2002 O.30.68 30.68
2003 35.7 30.68 66.38
2004 35.7 32.89 68.59
2005 53.7 35.10 88.80
2006 o.36.91 36.91
2007 35.7 36.91 72.61
2008 O.38.62 38.62
2009 35.7 35.15 70.85
201 0 O.39.68 39.68
Total $1,710.$583.$2,292.
Present
Worth @ 3%$1,342.$331.$1,673.
T
25938
7-11
-
,""'"
TABLE 7-7
ENVIRONMENT RELATED POWER PLANT CHARACTERISTICS
COMBINED,CYCLE POWER PLANT
KENAI AREA POWER GENERATION -LOW LOAD FORECAST
Air Environment
Emissions
Particulate Matter
Sulfur Dioxide
Nitrogen Oxides
PhYsical Effects
Water Environment
Below standards
Below standards
Emissions variable without standards -
dry control techniques would be used to
meet calculated NOX standard of 0.014
percent of total volume of gaseous
emissions.This value calculated based
upon new source perfonnance standards~
facility heat rate~and unit size.
Maximum structure height of 50 feet
Plant Water Requirements 500 GPM
Plant Discharge Quantities 100 GPM
Wastewater Holding Basin
including treated sanitary
waste~floor drains~boiler
b1ow-down~and deminera1izer
wastes
Land Envi ronment
,T
T
Land Requirements
Plant and Switchyard
Socioeconomic Environment
Construction Workforce
Operating Workforce
25938
120 acres
Approximately 200 personnel at peak
construction
Approximately 130 personnel
7-12
-
-
Approximately 500 gpm of fresh water will be supplied by groundwater
for water or steam injection (for NOx control).equipment wash-down.
boiler make-up water.and potable supplies.This amount of water will
not significantly affect groundwater supp1 i es in the area.Wastewater
discharges will be less than lOa gpm and will be treated to meet
effluent gUidelines:
Aquatic resources.as for the medium load forecast.will not be
significantly affected.Plant acreage will be approximately 120 acres
as compared to 17 5 acres for the medium load forecast.Terrestri al
impacts are correspondingly reduced.
Impacts associated with the transmission line from Kenai to Anchorage
and on to Fairbanks are identical to those discussed in Section 6.4 for
the medium load forecast.
Socioeconomic impacts are expected to be similar to those for the
medium load forecast.They would be less significant for the low load
forecast.The in-migrating workforce.which would have to seek
temporar,y housing on their own.would be smaller than for the medium
growth forecast.and thus would cause fewer demands on local housing
and public services.
25938
7-13
I
8.0 COMPARISON OF SCENARIOS
The three development scenarios have a common purpose of meeting the
electrical generating needs of the Railbelt Region using North Slope
gas as a fuel source.However,the electric generating schemes and
auxiliary systems vary widely among the scenarios making comparison of
their relative merits complex.Table 8-1 is a side-by-side comparison
of some of the important features of the three scenarios for both
medium and low load forecasts.Each power plant meets the respective
electricity demand forecast for the Railbelt.The Kenai plants also
include the anticipated electrical requirements of the TAGS gas
.conditioning and liquefaction facilities.Simple cycle units are the
recommended technology for ele~tric generators on the North Slope,but
combined cycle is more appropriate for the other two scenarios.The
environmental and socioeconomic effects of all development scenarios
are substantial,but~have been identified which would preclude any
proj~ct.All scenarios re technically feasible from an engineering
point of view.(7)
q~e~
The ultimate feasibility of each development scenario described herein
will depend upon a comparison of power costs between these scenarios
and alternative electric generating technologies.Such comparisons are
outside Ebasco's scope of work,but can be considered as a logical
extension of these studies which may be performed by the Alaska Power
Authority.
2603B
8-1
TABLE 8-1
COMPARISON OF SCENARIOS
Power Plant Location
Factor
North Slope
Medium Low
Fairbanks
Medium Low
Kenai
Medium Low
Power Plant 1365 728 1383 726 1743 1116
Capacity {MW}
Required Units (Simple 15/0 8/0 2/5 0/3 1/7 2/4
GYcle/Combined Cycle)
P1 ant Si te Acreage 90 60 140 90 175 120
North Slope to Fairbanks 2 2
.NAIl NA NA NA
:,._--Transmission Lines (SOD kV)
Fairbanks to Anchorage 3 2 3 2 2 2
Transmission Lines (345 kV)
Kenai to Anchorage NA NA NA NA 2 2
Transmission Lines (500 kV)
North Slope to Fairbanks NA NA 10 3 NA NA
Pipeline Compressor
Stations
POWER GENERATION
0982 $Billion}
Capital Investment 4.2 3.3 6.2 4.7 2.1 1.7,
Total O&M 1.1 0.7 0.8 0.3 0.8 0.6
Pre sent Wort h 3.8 2.7 5.2 3.4 2.0 1.7
DISTRIBUTION SYSTEM
(1982 $Billion)
Capital Investment NA NA 1.1 1.5 NA NA
Total O&M NA NA 0.09 0.04 NA NA
Present Worth NA NA 0.9 1.1 NA NA
1/NA -Not appl icab1e
26038
8-2
r
r
r
9.0 REFERENCES
Acres Imerican,Inc.1981.Susitna hydroelectric project -
feasibility report -Volume 1,engineering and economics aspects,
final draft.Alaska Power Authority.Anchorage,Alaska.
Alaska Department of Fish and Game.1978.Alaska Fisheries Atlas.
Volumes I and II.Alaska Department of Fish and Game.Juneau,
Al aska.
Battelle Pacific Northwest Laboratories.1982.Railbelt electric
power alternative study:evaluation of rail belt electric energy
plans -comment draft.Office of the Governor,State of Alaska.
Juneau,Alaska (February 1982).
Beaulaurier,D.L.,B.W.James,P.A.Jackson,J.R.Meyer,and J.M. Lee,
Jr.1982.Mitigating the incidence of bird collisions with
transmission lines.Paper to be presented at the Third Symposium
on Environmental Concerns in Rights-of-way Management,San Diego,
California,February 15-18,1982.21 pp.
Bonneville Power Administration.1981.Underground cable systems:
Potential environmental impacts,Draft Report.Bonneville Power
Administration,Washington,D.C.
Bureau of Land Management.1980.The utiliy corridor,land use
decisions.U.S.Department of the Interior,Bureau of Land
Management,Fairbanks,Alaska.
Commonwealth Associates,Inc.1982.Environmental Assessment Report
for the Anchorage-Fairbanks Transmission Intertie.Alaska Power
Authori ty,Anchorage,A1 aska.
Commonwealth Associates.1978.Model for the ready definition and
approximate comparison of alternative high voltage transmission
systems.DOEjETj5916-1.
Commonwealth Associates,Inc.1981.Anchorage-Fairbanks transmission
intertie route selection report.
The Governor's Econqmic Committee.1983.Trans Alaska Gas System:
economics of an alternative for North Slope Natural Gas.State of
Alaska,Office of the Governor,Anchorage,Alaska.
Leopold,A.and F.Darling.1953.Effects of land use on moose and
caribou in Alaska.Transactions of the North American Wildlife
Conference.18:553-582.
North Slope Borough.1978.Coastal management program,Prudhoe Bay
Area.North Slope Borough,Barrow,Alaska.
2588B
9-1
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r·
r
r
'I
Schmidt,D.R.,Neterer,C.,Willing,D.,Troy,P.Olson.1981.
Fisheries resources along the Alaska Gas Pipeline route (Prudhoe
Bay to Yukon Territroy)proposed by Northwest Alaskan Pipeline
Company.A summary report.Prepared for Northwest Alaskan
Pipeline Compay by LGL Alaska Research Associates,Inc.608 p.
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of the moose of South Central Alaska.Transactions of the North
American Wildlife Conference.18:539-552.
u.S.Army Corps of Engineers.1978.Kenai river reivew.U.S.Anmy
Corps of Engi neers,Al aska Di strict.Anchorage,Al aska.
U.S.Department of Commerce.1979.Environmental assessment of the
Alaskan Continental Shelf,Lower Cook Inlet Interim synthesis
report.U.S.Department of Commerce,National Oceanic and
Atmospheric Administraton,Environmental Research Laboratories,
Boulder,Colorado.
u.S.Department of Commerce.Federal safety standards for
transportation of natural gas and other gas by pipeline.49 CFR
Part 293,Latest Edition.
U.S.Department of Commerce.Ameri can standard code for gas
transmission and distribution piping systems.B 31.8,Latest
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University of Alaska,Arctic Environmental Information and Data Center.
1974.Alaska Regional Profiles,Southercentra1 Region.State of
Alaska,Office of the Governor,Juneau,Alaska.
2588B
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"I