HomeMy WebLinkAboutConceptual Design & Cost of a 30 Megawatt Coal Fired Power Plant for Kodiak AK 1981
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PROCESS AND AUXILLIARY SYSTEM DESCRIPTION... .
FUEL SUPPLY...
SITE SERVICE
CONSTRUCTION
TABLE OF CONTENTS
1-1
. 1-2
. 2-1
. 2-1
2-15
. 2-16
2-17
. 2-18
« 3-1
3-1
3-4
. 3-5
The plant site required is some 30 acres including fuel handling and
storage, the power plant itself, the ash handling systems and pond, and
buffer zones for aesthetic protection. Figure 1-1 is a general
pictoral view of the facility.
1.2 GENERAL PERFORMANCE CHARACTERISTICS
The plant is designed to burn coal from the Usibelli mine. This coal
is low in sulfur and has a higher heating value of 8,000 Btu/1b.
The heat balance of the steam generator is shown, in simplified form
(without blowdown and associated steam and heat recovery systems) in
Figure 1-2. The heat balance of the power generation cycle is shown in
Figure 1-3. The steam generator has a calculated thermal efficiency of
80.4 percent and the power generation cycle has a heat rate of 9,437
Btu/kWh. Therefore, the overall plant heat rate is calculated at
11,738 Btu/kWh (the power plant efficiency is 29.1 percent). On that
basis the plant consumes 22 ton/h of coal and discharges 2.5 ton/h ash.
The technical description and cost estimate of this plant are presented
in subsequent sections.
1-2
COAL
STORAGE
PIEE
STEAM | GEN. BUILDING
COAL BARGE OFFLOADING J
COAL TRANSFER
BUILDING
PICTORIAL
VIEW, 30 MW PLANT
DRY STACK GAS H,0 IN STACK GAS 2 H=63.4 H=1176 RADIATION & OTHER M=315.3x193 M=26. 8x102 Q=7.04x106 Q=20.0x10 Q=31.5x106 % T=350 T=350
HIGH PRESSURE STEAM
>
H=1453.1 M=270,600 ¢ Q=393.2x10 T=900 AIR (%xcs=20)
H=0 M=303.1x103 FEEDWATER a Q= are HE T=80 H=406.9 H=270, 600 Q=110.1x10 T=430
H=8000 M=44.03x103 Q=352. 3x10 T=80
ASH AND UNCOMBUSTED FUEL
H=2..8 M=4.99x103 Q=10.6x106
LEGEND:
H=Enthalpy (Btu/1b)
M=Mass (lbs)
Q=Heat Flow (Btu)
T=Temp (°F)
FIGURE 1-2 SIMPLIFIED HEAT BALANCE OF
STEAM GENERATOR
HEAT BALANCE OF POWER GEN
STEAM GENERATOR
FIGURE 1-3
270 ,600#
865P-906°F-1453.
RATION CYCLE
!
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183634 & L 1.5"HgA
1377.4n id id
ae | 147048 \ | & 1303.24 ft
1 I | |
\ \ | 10316# al r P 1228.51 SIs
! | |= | |
|
- = |
1 9454 a te 1439. 4H 8 wo 7 = 3 Bis § a “ale . = 8 elk 7 g =o scuba oe “Ta
#5 Heater #4 Heater 45 eee cE #2 Heater #i Heate ; 169.5? Deaorator | SINS |g. 41P 8.35P 2706004 A 2706008 AP 70. 6P 4, 224,3554 a 224,3554 224,355#
430° 383.2 303.5° 179.8" Vv 94.0"
4o7h | ssertn 337.0h S°FTTO 273.2h 5° FTTO | 148.0h_p | 5° FITO| 62.4h
oF FTO Tor Fv } jo? FTTO _ [tor FTO] TO” FTO
183634 330674 144204
gee 315.9° 189.8°
346.4h 286. 2h 157.8h
2706004 = 317634
305.9° : 277.6h eo
LEGEND:
- Enthalpy, Btu. 1b
- Temperature, °F
- Flow, Lb/Hr
- Pressure, Psia
Generator
Output
30,000 _kW
1921034
994.3H
72.0h
2.0 TECHNICAL DESCRIPTION
2.1 PROCESS AND AUXILIARY SYSTEM DESCRIPTION
2.1.1 Overview
Coal-fired steam-generating stations of today's design are a well known
technology. Mechanically pulverized coal is mixed with air and blown into a —— furnace for combustion. The furnace contains walls of tubing filled with
high pressure water which is generated into steam by the thermal energy of
the combustion process. The steam is then exposed to a hot gas stream and
becomes superheated by absorbing more energy. The energy contained in the
steam is then piped to the steam turbine where the energy is transformed
into mechanical energy. High pressure steam is converted into mass velocity
by pressure reduction and blown into the turbine blades. This process con-
verts the mass velocity to mechanical rotating energy (controlled wind-mil]
principle) which in turn drives an alternator (generator) producing the
electricity. The steam after releasing all of its usable energy is
condensed by cold water and pumped back into the steam-generator for reuse.
The station's design parameters have been selected to include throttle steam
at 865 psig/900°F. The process shows the steam-generator being fed with 20
to 25 tons of coal per hour to generate 270,600 pounds per hour (1bs/hr)
steam. The coal is fed into the furnace by a spreader stoker, Particulate
and NO. emissions are reduced by staged combustion or by recirculation of
combustion gases. The other antipollution controls are in the exhaust of
the steam-generator, including a lime slurry FGD system for sulfur dioxide
(S05) suppression, and a baghouse for particulate collection. The furnace
will also have steam sootblowers on the tubing wall which will permit
cleaning of the heat exchange surfaces during operation.
The steam from the steam-generator is expanded in the turbine. The turbine
exhausts to the condenser which operates at a vacuum Corresponding to the
vapor pressure of the exhausting steam. Noncondensable gases are removed by
vacuum pumps. The condenser is cooled by ocean water adjacent to the plant
site.
2-1
The condensate from the steam cycle is pumped from the condenser through two heaters fed by extraction steam from the turbine to the deaerator where any
gases including oxygen are removed from the water.
From the deaerator the feedwater is pumped again through two heaters, fed by
extraction from the turbine, back to the steam-generator. The feedwater
temperature at the steam-generator is about 430°F where it is further heated
by an economizer.
The plant arrangement is shown on the plot plan (Figure 1-1). The basis is
the arrangement of the turbine building and the steam-generator (boiler)
with its accessories which lead to the stack. The basic arrangement of the
turbine building and boiler building has been chosen for compact design
minimizing the length of major piping. This arrangement can be turned as a
block in any direction to suit the transmission line direction and/or the
fuel delivery system and water supply system.
For estimating purposes it is assumed that the plant is at least 1/10 mile
from the waterfront unloading facilities. The site is assumed to be
basically flat and rocky. It is adjacent to the Coast Guard Station to
avoid problems of access to a remote site.
2.1.2 Fuel Handling System
Coal Unloading Station
The type of coal unloading station required for the plant is dependent on
the coal transportation system. Coal will be delivered to the Kodiak site
by barge. The type of coal unloading station required is a function of the
mode of transport of the coal and the size of the power plant, hence the
fuel requirements. In this case the coal will be transported to Kodiak by
barge. The size and heat rate of the power plant have been stated
previously.
2-2
The coal unloading station, therefore, consists of a 700 TPH clamshell barge
unloader and a vibrating feeder discharging to a belt conveyor. The coal is
transported to a distribution shed and then to outside storage (see Figure
2-1).
Stacking and Reclaiming
Initial coal deliveries at both sites will be used to establish a 32,000 ton
(60 day) compacted dead or long term storage pile. The cap over the dead
storage pile will be used for a 6000 ton live storage pile. The live
storage capacity will be an 1l day supply at full load plant operation.
Once the dead storage pile has been established and compacted, subsequent
coal deliveries will be transported by an inclined/overhead conveyor tripper
from the unloading hoppers to form the live storage pile. The belt tripper
will be enclosed and weather protected the entire length of the live storage
pile.
The entire coal storage pile (dead and live) will be approximately
600,000 ft. It will occupy a space of about 1/2 - 2/3 acre. The coal
will be reclaimed by a front end loader feeding to yard reclaim hoppers.
The reclaim hoppers discharge to inclined conveyors that will take the coal
to the coal gallery. There, the coal will be transferred to conve yors
feeding the plant silos.
Plant Storage
In-plant silo storage capacity will be 40 hours. The silos are situated
above the mills for gravity feed and will be provided with a fire protection
system.
2.1.3 Steam-Generator
The energy in the coal must be converted to high temperature and pressure
steam in order to produce useful work. This process takes place in the
steam-generator or boiler via coal combustion. The steam-generator for this
30 MW station will be an indoor spreader-stoker type designed to burn
2-3
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COAL AUNDLING FLOW DMG UNIT NO f° - loareasien
run-of-the mine coal. The design parameters for the steam-generator are
presented in Table 2-1.
The boiler, turbine operator, and air quality. control systems will be housed
in a single enclosed weatherproof building. The building will be of steel
construction insulated with aluminum sandwiched insulation suitable for the
environment.
2.1.4 Turbine-Generator
The steam produced in the steam-generator is conveyed to the turbine where
the steam's energy is converted to mechanical energy. The turbine rotor is
connected to the generator which, when rotated, produces electricity.
The turbine is to be of the 30 MW rating with five extraction stages and
bottom exhaust. The five extractions are to be used for feedwater heating
for the boiler. Turbine design conditions are as follows:
Throttle pressure 865 psig Superheat Temperature 900°F Turbine Backpressure 1.5 in. Hg
Final Feedwater Temperature 430°F
The generator is to be designed for maximum capability of the turbine with a
power factor of 0.85 and all cooling and sealing equipment is to be included.
All equipment is to be designed for indoor installation. The turbine-gener-
ator is to be equipped with all local and control room supervisory instru-
mentation, including valve testing station and protective devices. Oil
reservoir, oil cooler, and A-C and D-C oi] pumps as well as the gland seal
system including piping as normally supplied with the turbine-generator, are
to be included.
In addition to the turbine-generator, condenser, condensate pumps, some of
the feedwater heaters, feedwater pumps and other miscellaneous equipment,
the building will also contain the control room, water transfer pumps,
service water pumps, instrument air compressors, service air compressors,
demineralizers, and motor control centers.
2-5
TABLE 2-1
STEAM-GENERATOR DESIGN PARAMETERS
Steam Flow At Superheater Outlet
Steam Pressure At Superheater Qutlet
Steam Temperature At Superheater Outlet
Feedwater Temperature At Economizer Inlet
Coal Heating Value
Ash Content of Coal
Moisture Content of Coal
Sulfur Content of Coal
Nitiogen Content of Coal
Ash Softening Temperature
Hardgrove Grindability Factor
Ash Sodium
270,600 1b/h
865 psig
900°F
430°F
8000 Btu/1b
8-10 percent
28 percent
0.2 percent
0.6 percent
2350°F
25
0.1 percent
2-15. Etectrical oP brant
Ratings of the major pieces of electrical equipment are as follows: Ue
- Generators, 35,294KVA; 0.85PF, 30MW, 20KF ve
- Main Transformers, 12.5 delta to 69KV
- Auxiliary Transformers, 3 winding 20MVA, delta to 4.16/4.16KV delta
- Startup Transformer, 3 winding 20MVA, 69KV delta to 4.16/4.16KV wye
- Switchgear 4.16KV medium voltage
- Power Centers, motor control centers distribution panels etc. as required
2.1.6 Heat Rejection System
The steam exiting the turbine is cooled to increase pressure differential
across the turbine which subsequently causes the turbine to spin. In the
cooling process, the steam is condensed and returned to the boiler for
reuse. The cooling is effected in a heat exchanger (i.e., condenser) where
an “outside" coolant (i.e., circulating cooling water) is used to cool the
steam.
The condenser is to be a single shell two pass with divided water box and
hotwell. The hotwell is to have enough storage to allow proper level con-
trol for surging and shall be properly baffled to keep the condensate at
saturation temperature. The condenser shall include Muntz Metal tube sheets
and inhibited Admiralty tubes with 70-30 copper nickel tubes in the air
removal sections and the impingement areas. The condenser is to be shop
fabricated including tubing and should be suitable for sea and barge ship-
ment. The condenser will be used in a once through cooling application.
For purposes of estimating an inexpensive intake channel along the bottom of
Women's Bay was assumed. Lined 36 in. carbon stcel pipe was assumed for
incoming and discharge water. It should include a condenser neck with
dogbone type rubber expansion joint for connection to the turbine exhaust.
Condenser design data are as follows:
2-7
Heat load 191 x 10° Btu/hr
Tubes 1" 18 BWG x 36 ft
Maxixmum Water Velocity 6.5 ft/sec
Backpressure E.5. th. HG
Circulating water pumps of the vertical pit type will be used. Traveling
screens will be installed to protect the equipment from fish.
2.1.7 Water Quality Control
The station water uses for a 30 MW coal-fired steam electric plant have been
estimated for a Kodiak Island, Alaska location. Uses were determined for
once-through marine cooling with wet ash sluicig system. A detailed water
balance is presented in Figure 2-2. This system employs a flue gas
desulfurization system (FGD), and a baghouse as required. Ash generation is
assumed to average approximately 2.5 ton/hr (bottom ash plus collected fly
ash) at full capacity.
Ash Hendling System
The system employed uses wet ash handling. This system is depicted in
Figure 2-3. Due to regulatory changes and uncertainties, this would have to
be reevaluated if more detailed design were contemplated. Significant to
note is the fact that transport water from the ash ponds will be recycled.
Ash ponds will be developed on 5-year increments and revegetated.
Floor Drainage Treatment Facility
This facility will provide treatment for the removal of suspended solids and
oi 1/grease and will require both a primary and secondary treatment stage.
The primary stage will consist of a gravity oil/water separator which will
accomplish both suspended solids and floatable oi] removal. The secondary
p———._ 70 RECEIVING t aep LLDTREAM
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NOTES:
I-ALL FLOWS ARE EXPRESSEDIN
GALLOUSTER MINUTE (GPM).
2- FLOWS ARE OMILY AVERAGES AT 100%}. CAPACITY FACTOR.
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FIGURE 2-2
AUXILIARY
Cooling
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WATER BALANCE DIAGRAK
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stage will consist of treatment for the removal of emulsified oils utiliz-
ing either cartridge type separators or chemical coagulation. This prefab-
ricated facility will be designed to handle an average daily flow of 5 gpm.
The treated effluent will be discharged to the wastewater collection pump
for reuse.
Yard and Area Drainage System
The yard and drainage system will effectively convey all runoff from the
plant site to minimize potential site flooding. This discharge is not con-
sidered to be a pollutant source or wastewater requiring treatment because
no contamination of this discharge will occur on-site due to either process
or materials storage activities.
Coal Pile Runoff Holding Pond Facility
Runoff and filtrate from the coal storage pile will be directed to collect-
jon ditches located on the periphery of the pile and then conveyed to the
coal pile runoff ponds for treatment prior to disposal to the yard and area
grainage system. The holding pond will provide gravity settling for coal
fines (suspended matter) washed out of the pile and pond effluent in excess
of the design storm event will undergo pH adjustment, as necessary, to a
range of 6.0 to 9.0 by the addition of caustic reagents.
2.1.8 Air Quality Control
Due to the low sulfur content in the coal (0.2 percent by weight) and the
stringent emission requirements of the New Source Performance Standards, the
air quality control configuration for the plant will be a semi-dry flue gas
desulfurization (FGD) system followed by a fabric filter baghouse.
The FGD system will consist of two spray dryer vessels using a lime slurry.
The FGD system will be designed to remove 70 percent of the sulfur dioxide
from the gas stream at the unit's rated load. Control of the spray dryer
will be governed by both the temperature and $0, concentration of the exit
2-11
flue gas. The flow of lime to the system will average 150-200 pounds of lime per hour. Lime pebbles will be hydrated on-site by a single slaker and Pneumatically transported to two storage silos each located near a spray dryer. These silos will have a 6-month holding capacity. From the silos,
the hydrated lime will be pneumatically transported to mixing tanks provided
below each spray dryer vessel. The two mixing tanks will be sized at for
10-day capacity.
The fabric filter baghouse for particulate removal will consist of four
parallel rows of compartments. Fabric filters will be designed to achieve a particulate removal efficiency corresponding to a maximum emission rate of
0.03 1b per 10° Btu heat input to the boiler. Filter Cleaning will be by both reverse air and shaker methods and will be automatically programned to
be activated every 1/2 hour to 1 hour. Filter bags will be synthetic fabric
coated with acid-resistant polymer resin for a service life of approximately
3 years. Continuous baghouse hopper ash removal will be required.
2.1.9 Ash Handling System
A steam-generator which burns coal containing uncombustible mineral matter
produces solid refuse classified, in general, as aSh. The ash is of two
types: bottom ash/slag and fly ash. Bottom ash is the material dropped out
of the combustion products in either a dry or molten state to the furnace
bottom and collected in water impounded bottom ash hoppers. Fly ash
consists of fine particles which leave the furnace with the flue gas and are
collected in the baghouse system.
The total quantities of ash to be generated are a function of the ash con-
tent of the coal and the steam-generator coal firing rate. Based upon the
plant's design specifications discussed in previous sections of this report,
and assuming a fly ash/bottom ash ratio of 40/60, the anticipated quantities
of ash are as follows:
2-12
Average Maximum
Total Ash Production Rate 2.5 tons/hour 3.0 tons/hour
Bottom Ash Production Rate 1.5 tons/hour 1.8 tons/hour
Fly Ash Production Rate 1.0 tons/hour 1.2 tons/hour
Bottom Ash
The bottom ash will be continuously removed from the boiler. A water-filled
trough is to be located below the boiler hopper openings and will contain a
conveyor arrangement. This equipment will be sized for a maximum capacity
of 3.0 tons per hour based on a maximum coal ash content of 10 percent.
Flyash
The flyash collected in the baghouse hopper and in the duct hoppers and the
baghouse, will be transported to a flyash storage silo.
2.1.10 Solid Waste Disposal System
From the storage silos located at the plant site, all plant solid waste will
be trucked to a permanent solid waste disposal site, assumed to be situated
in close proximity to the plant island.
2.1.11 Other Major Plant Equipment
Condensate Pumps
Two (2) vertical motor driven canned pumps designed for indoor installation
are required. Each will have a capacity of 50 percent with the thrust
bearings in the motors. The capabilities of each pump and motor are as
follows:
Condensate Temperature 92°F
Condensate Flow 224 x 103 lbs/hr
2-13
The condensate pump length should be such that the NSPS required will not
exceed the elevation of the suction flange when running at 130 percent of
design capacity. The pumps shall be designed for parallel operation over
the full range.
Feedwater Heaters
The feedwater heating system will have 4 closed type feedwater heaters and
one open type feedwater heater (deaerator). The closed type feedwater
heaters consist of 2 high pressure heaters and 2 low pressure heaters. The
heaters will be of bolted head design. The high pressure heaters are of the
integral desuperheating and draincooling design. The low pressure heaters
are to have integral drain coolers. The high pressure heaters will cascade
drain to the deaerator and the low pressure heaters will cascade drain to
the condenser. All heaters shall be of the U-tube removable shel] design
complete with roller type supports.
The deaereator mounted on top of a five-minute capacity storage tank is to
be integrally connected and equipped with stainless steel troughs and baffle
plates. All nozzle connections for steam and feedwater are to be provided
as nonnally required in a modern power plant for indoor installation.
Design conditions for the deaerator are as follows:
Water Storage 20 x 103 Ib
Water Flow (In) 224 x 108 Ib/hr
Water Flow (Out) 271 x 109 1b/hr
Design Pressure 110 psig
Operating Presure 70 psia
Feedpumps
Two (2) motor driven 50 percent capacity feedpumps and one hot standby
turbine driven feed pump for indoor installation will be required. The
feedpumps are to be of the multistage barrel type with an interstage takeoff
for reheat desuperheating. Each feedpump is to be complete with motors,
2-14
shaft driven and electric driven oil pump, oi] cooler and oil tank, all
mounted on a common base plate. The glands are to be sealed by mechnical
seals. Each pump is to be designed for the following capability:
Feedwater Temperature 310°F
Feedwater Flow 271 x 10° 1b/hr
Suction Pressure 100 psig
The pumps should be able to operate out to 130 percent flow and the charac-
teristic should be steadily rising toward shut-off without exceeding 120
percent of the design head.
2.2 FUEL SUPPLY
The fuel supply is assumed to consist of Usibelli Mine coal, similar to that
burned at the Healy 25 MW power plant. This coal has a higher heating value
of 8,000 Btu/1b, a maximum moisture content of 28 percent, a typical ash
content of 8 to 10 percent, and a sulfur content of 0.2 percent.
All of the coal will be barged to the Kodiak site. Assuming a power plant
Capacity factor of 80 percent and a heat rate of 11,740 Btu/kWh, some
154,000 tons/yr will be required.
2.3 SITE SERVICES
The construction and operation of a 30 MW coal-fired power plant will
require a number of related services to support all work activities at the
site. These site services could include the following depending upon the
actual location of the power plant:
o Access Roads
o Landing Facility
o Labor Camp
2-15
2.3.1 Access Roads
Gravel roads with a 9-inch gravel base will be required to connect the Plant
site with the equipment landing facility. This road will be of minimal
length.
2.3.2 Landing Facility
The site will require construction of a marine landing facility to receive
all construction materials, equipment, and supplies. This would be built in
concert with the coal unloading facility.
2.3.3 Labor Camp
Due to the need for over 100 workers on site a labor camp was assumed. Its
costs include site preparation, development of a potable water supply,
housing, sewerage and garbage disposal, recreation facilities, power supply,
and managerial and supervisory office buildings. It is considered as an
individual cost. Facilities built for the labor camp will be retained as
part of the permanent installation as appropriate (e.g., wastewater
treatment).
2.4 CONSTRUCT ION
The number of workers necessary for construction of a 30 MW station will
vary over the approximate three year construction period. Construction of
this facility will require about 750,000 man-hours or 375 man-years of labor.
Construction of this 30 MW station will follow nonnal acceptable consiruc-
tion methods. While the steam flow exceeds the limits of packaged boilers,
a modular design may be employed. A program of this magnitude begins with
orderly development of the following requirements:
2-16
1) Utility services, such as electric light and power, water for industrial and potable use and fire protection, sanitary facilities, telephone communications, etc.
2) Temporary construction office facilities (with heating and ventilation furnished by contractors as required).
3) Temporary and permanent access roads, and railroad spur if required.
4) Temporary enclosed and open laydown storage facilities.
5) Oelivery of various types of construction equipment and vehi- cles, such as earth-moving equipment, concrete and materials hauling equipment, cranes, rigging equipment, welding equipment, trucks and other vehicles, tools, and other related types of construction equipment by truck, rail, or landing craft or a combination of these depending on the site.
6) Temporary office and shop spaces for various subcontractors.
7) Settling basins to collect construction area storm runoff.
8) Perinanent perimeter fencing and security facilities.
9) Safety and first aid facilities in strict compliance with OSHA regulations.
Following completion of these initial construction site related activities,
power plant systems construction will be initiated.
2.5 OPERATION AND MAINTENANCE
When the coal-fired steam-electric power plant begins commercial operation,
the facility will provide employment for approximately 35 employees,
including a superintendent and assistant superintendent. The estimate of
the plant's staffing requirements is based upon conversations with the
superintendent of the Healy Plant of Golden Valley Electric Association.
Employment of these personnel will continue throughout the 35-year life of
the plant.
Plant systems will be operated from the control room located in the main
plant building. Some of the systems and equipment will also be controlled
from local stations. In general, controls are automatic, although operators
2-17
can override the automatic controls and operate the plant Manually. To
supplement the operational controls, the station will be equipped with an
alarm system, fire protection system, Proper lighting, and a radio-telephone
communication system.
To prevent mechanical failure, periodic maintenance will be performed on all
pressure systems, rotating machinery, heat sensitive equipment, and other
operating equipment for malfunctions, leaks, corrosion and other such abnor-
malities. In addition, the maintenance programs will monitor the revegeta-
tion and erosion prevention programs initiated during the cleanup phase of
construction. Trained maintenance crews will perform operational mainte-
nance and will correct emergency malfunctions.
In general all major maintenance functions will be performed during the
plant's annual scheduled outages. The length of time required for these
scheduled outages is estimated to be approximately 675 hours per year. This
value corresponds to a scheduled outage rate* of 8 percent.
* Scheduled Outage Rate = Scheduled Outage Hours x 100
Service Hours + Scheduled Outage Hours
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3.0 COST ESTIMATES
3.1 CAPITAL COSTS
A conceptual cost estimate for this 30 MW power plant has been developed,
and is presented in Table 3-1. This cost estimate assumes "overnight
construction." There are no allowances for interest during construction,
price escalations over time, or other similar factors. The cost estimate is
conservative, and has an accuracy level of #25 percent.
3.1.1 Basis of Capital Cost Estimate
This conceptual cost estimate is based upon the Ebasco Code of Accounts
rather than the Federal Energy Regulatory Commission (FERC) code of
accounts. It is based upon a wealth of specific project experience.
The estimate includes all facilities and systems required for an effective,
self sustaining unit, except for the following items:
chemistry laboratory;
barges for coal and limestone delivery;
front end loader or bulldozer for coal handling;
dredging, if required, for barge unloadig facility; and o oOo Co switchyard and transmission facilities.
The estimate of construction costs assumes that the entire job will be
performed on a subcontract basis. It has a high labor cost due to the need
to employ a work week of six ten-hour days. Additional costs are estimated
based upon climate and the resulting construction schedule.
Because this is a conceptual cost estimate, the following costs were also
exc luded:
Oo sales and use taxes;
o land and/or land rights;
o allowance for spare parts; and
O owner-associated monitoring costs.
3-1
TABLE 3-1
CONCEPTUAL COST OF 30 MW COAL-FIRED POWER PLANT FOR KODIAK (1981 x 103)
Cost Category Material Installation Total
Improvements to Site 400 1,200 1,600
Earthwork and Piling 900 3,400 4,300
Circulating Water System 500 1,000 1,500
Concrete 900 2,900 3,800
Structural Steel, Lifting
Equipment, Stacks 1,200 1,000 2,200
Buildings 1,200 2,100 3, 300
Turbine Generator and
Accessories 5,000 300 5,300
Steam Generator and
Accessories 4,000 2,300 6,300
Other Mechanical
Equipment 2,000 600 2,600
Coal and Ash Handling
Equipment 3,200 1,400 4,600
Piping 2,400 2,800 5,200
Insulation and Lagging 400 900 1,300
Instrumentation 500 100 600
Electrical Equipment 3,500 3,600 7,100
Painting 100 500 600
Air Quality Control Systems 5,200 4,100 9,300
Waterfront Construction 1,300 1,700 3, 000
Substation 300 100 400
SUBTOTAL 33,000 30, 000 63,000
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TABLE 3-1 (CONTINUED)
CONCEPTUAL COST OF 30 MW COAL-FIRED POWER PLANT FOR KODIAK (1981 $ x 103)
Cost Category Material Installation Total
Allowances for Construction
Timing and Scheduling Due to
Climatic Reasons 8, 000
TOTAL DIRECT COST 33,000 38,000 71,000
Indirect Construction 9,000
Contingencies ‘ 10,000
A and E Services 7, 000
TOTAL INSTALLED COSTS 97,000
($3,233/kW)
3-3
3.1.2 Implications of Capital Cost Estimate
With respect to the cost estimate, it is of particular importance to note
that, while the steam generator (boiler) is too large to be supplied as a
package unit, it could be supplied in modular fashion with much of the
fabrication occurring at the site of manufacture. It is also of importance
to note that the operating pressure of the boiler is sufficiently modest
(865 psig) to obviate the need for extensive feedwater treatment. It is
also significant to note that these capital costs represent a very early
point on the economies of scale curve. This plant is sufficiently large
that field erected systems are necessary and all stack gas control systems
are required (e.g., S05 scrubber, baghouse). The level of sophistication
in plant design is similar to a 100 MW power plant with the exception of a
reheat cycle. Thus, the resulting capital costs are $3,233/kW installed.
3.2 OPERATION AND MAINTENANCE COSTS
3.2.1 Operation and Maintenance Costs
The operation and maintenance costs for the 30 MW size plant, expressed in
1981 "Alaskan dollars", are as follows:
Fixed Costs
Staff (35 Persons) $1,070, 000
or $16.71 /kw-yr
Variable Costs
Operating Supplies and Expenses $ 42, 000/yra/ or 0.2 mils/kwh
Maintenance Supplies and Expenses $ 84,100/yra/
or 0.4 mils/kwh
a/ Assumes an 80 percent capacity factor.
3-4
3.2.2 Escalation
Estimated real escalation of fixed and variable Operation and maintenance costs are as follows:
Escalation Year (Percent)
1981 V5 1982 25 1983 1.6 1984 1.6 1985 hg 1986 1.8 1987 1.8 1988 220 1989 2-0 1990 2.0 1991 - on 2.0
3.3 FUEL COSTS
Coal could be obtained from a variety of sources for the 30 MW Kodiak power
plant. All such coal would have to be barged to the user facility.
Recent estimates presented in the Request for Proposal for Cordova, Alaska
were $45/ton for Usibelli Mine coal delivered by barge to Cordova. This
price would probably not change appreciably if coal were barged to Kodiak.
It was further stated that this coal price could be reduced in 5 to 8 years
by development of the Beluga coal fields near the Cook Inlet.
These coal costs are equivalent to $2.81/Btu x 106. at a heat rate for
the power plant of 11,740 Btu/kWh, fuel costs are estimated at 33.0 mils/klh.
3.4 COST SUMMARY
Resulting from this effort is a conceptual plant with an installed capital
cost of $3,233/kW (#25 percent).
3-5
A summary of 1981 non-capital charges, assuming a capacity factor of De8 Ts
as follows:
Cost
Cost Category (mi 1s/kWh)
Labor Sl
Supplies and Expenses 0.6
Fuel 33,0
Total 38.7
3-6