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Susitna-Watana Hydroelectric Project Document
ARLIS Uniform Cover Page
Title:
Susitna Hydro transmission study, EPS Job #09-0254
SuWa 193
Author(s) – Personal:
Prepared by James W. Cote, David W. Burlingame, Kelly Ridge
Author(s) – Corporate:
Electric Power Systems, Inc.
AEA-identified category, if specified:
AEA-identified series, if specified:
Series (ARLIS-assigned report number):
Susitna-Watana Hydroelectric Project document number 193
Existing numbers on document:
EPS Job #09-0254
Published by:
Redmond, WA : Electric Power Systems, Inc., [2009]
Date published:
October 22, 2009
Published for:
Prepared for Alaska Energy Authority
Date or date range of report:
Volume and/or Part numbers:
Final or Draft status, as indicated:
Document type:
Pagination:
iii, 12, [236] p.
Related work(s):
Pages added/changed by ARLIS:
Notes:
From the Alaska Energy Authority's Susitna Reports webpage (September 23, 2013).
All reports in the Susitna-Watana Hydroelectric Project Document series include an ARLIS-
produced cover page and an ARLIS-assigned number for uniformity and citability. All reports
are posted online at http://www.arlis.org/resources/susitna-watana/
Susitna Hydro Transmission Study
EPS Job #09-0254
Prepared for:
Alaska Energy Authority
Prepared by:
Dr. James W. Cote, P.E.
David W. Burlingame, P.E.
Kelly Ridge
ELECTRIC POWER SYSTEMS, INC.
4020 148th Ave. N.E. Suite C
Redmond, WA 98052
October 22, 2009
AEA – Susitna Hydro Transmission Study
October 22, 2009 ii
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SUMMARY OF CHANGES
Revision Number Revision Date Revision Description
0 Oct 22, 2009 Initial Release
AEA – Susitna Hydro Transmission Study
October 22, 2009 iii
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TABLE OF CONTENTS
1 Executive Summary ............................................................................................................ 1
2 Introduction ......................................................................................................................... 3
3 Power Flow Base Cases and Modeling Issues ................................................................. 3
4 Transient Stability Cases ................................................................................................... 6
5 Transmission Cost Estimates ............................................................................................ 9
6 Conclusions ....................................................................................................................... 10
Appendix A – Power Flow One Line Diagrams ...................................................................... 11
Appendix B – Stability Plots .................................................................................................... 12
AEA – Susitna Hydro Transmission Study
October 22, 2009 1
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1 Executive Summary
Electric Power Systems, Inc. (EPS) studied the feasibility of adding a new hydro generation
plant at Susitna. Both 420 MW and 600 MW plant sizes were evaluated. The study evaluated
the feasibility of the project and performed a phase one study of the required system
improvements necessary to support the new generation and transmission.
The study indicates that the project is feasible. Numerous transmission system improvements
are required to support the proposed generation. Transmission improvements from Fairbanks
to the Mat-Su valley will be required, as listed below.
New Gold Creek 230 kV substation along the existing Railbelt 138 kV Northern Intertie at
Gold Creek.
Three new 230 kV lines between Gold Creek and the Susitna Hydro Plant.
The existing 138 kV line from Healy to Douglas will need to be converted to 230 kV.
Two new 230 kV lines connecting Douglas to the new substation at Gold Creek.
A new 230 kV line between Gold Creek and Healy.
A new 230 kV bus is required at Healy substation.
The existing 138 kV bus sections at Cantwell, Stevens, and Douglas must be converted
to 230 kV along with the substation step down transformers.
The Healy - Wilson 138 kV will be converted to 230 kV operation.
Two new 100 MVA, 230 / 138 kV transformers will be required at Wilson.
The existing Healy – Gold Hill 138 kV line will need to be upgraded to 230 kV operation.
The conversion of the Ester and Nenana substations to 230 kV will be required.
Two new 100 MVA 230 / 138 kV transformers will be required at Gold Hill.
Two new static VAR compensation (SVC) devices will be required to support the project.
The SVCs will most likely be required at Healy and Douglas, interconnecting at 230 kV.
A new 230 kV substation at Lorraine was added. This substation intersects the Pt.
MacKenzie - West Terminal – East Terminal – Plant 2 230 kV line and the Pt.
MacKenzie - Teeland 230 kV line.
A new 230 kV line from Pt. MacKenzie to Douglas was added.
A new 230 kV line from Lorraine to Douglas was added.
Some modifications to the spinning reserve policies and to the underfrequency load shedding
schemes will also be necessary.
The estimated costs of the transmission and substation projects are as follows (in millions):
Triple Circuit From Devils Canyon to Gold Creek - $47.4
Single Circuit 230 kV Gold Creek – Healy - $153.3
Double circuit 230 kV Gold Creek – Douglas - $192.1
Single Circuit 230 kV Douglas – Teeland - $37.9
Double Circuit 230 kV Douglas – Lorraine - $117.0
Single Circuit 230 kV Lorraine – Pt MacKenzie - $7.3
Convert 138 kV Healy – Gold Hill 230 kV line - $149.2
Pt MacKenzie Modifications - $2.4
Lorraine Substation - $13.4
AEA – Susitna Hydro Transmission Study
October 22, 2009 2
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Douglas Station - $14.3
Teeland Station - $1.0
Gold Creek Station - $17.0
Healy Station - $5.6
Wilson Station - $6.5
Nenana/Ester stations - $6.0
Intertie Transformers - $7.0
SVC systems - $52.0
Devils Canyon Substation (exc transformers) - $9.5
Unidentified projects - $50.0
Total Susitna Integration Costs - $888.9
The identified projects are those that are required as a result of a high-level screening study of
the Susitna Hydroelectric project. These projects include the major infrastructure necessary to
integrate the Susitna project into the Railbelt. However, there will be many projects, such as
communications improvements required for relaying and control, control and monitoring
(Supervisory Control And Data Acquisition) and minor transmission and substation
improvements that will be required to strengthen the interconnected grid of the Railbelt. These
projects cannot be identified by a high level screening study, but are estimated at $50.0 in the
above summary.
It should also be pointed out that certain improvements not included in the above list would be
required if slightly different generation dispatches were utilized in the study. The study assumed
200 MW of the Susitna project was utilized in the Fairbanks area and 400 MW was used in the
Anchorage/Kenai area. Differences in the actual power flow out of Susitna could result in
significant changes to the list of recommended projects. Power flow above 400 MW to the
Anchorage and Kenai areas may require transmission improvements from the Pt. MacKenzie,
Lorraine, Teeland area into the Anchorage area and from Anchorage to the Kenai Peninsula.
In all the power flows used in the study, Bradley Lake was required to be dispatched. Absent
the energy from Bradley Lake, acceptable power flows and system stability achieved in the
study would not be possible unless a Kenai gas-fired resource was used in Bradley’s place.
Without the addition of the Southern Intertie, the Kenai will be subject to essentially the same
generation restrictions that exist today. In order to alleviate Kenai “must run” generation, the
Southern Intertie would be required to optimally utilize the energy of Susitna on the Kenai
Peninsula.
AEA – Susitna Hydro Transmission Study
October 22, 2009 3
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2 Introduction
The Alaska Energy Authority (AEA) has asked Electric Power Systems, Inc (EPS) to determine
the required system improvements to the Railbelt electrical system to support the proposed
Susitna Hydroelectric Project (Project). Specifically, this study evaluated the feasibility of the
Susitna project and identified the basic electrical infrastructure improvements necessary to
support the project.
EPS evaluated the operation of the Railbelt electrical system with the addition of the project in
the 2020 time frame. EPS studied two generation levels for the project, 420 MW and 600 MW.
The project interconnects with the existing Railbelt system along the existing Anchorage –
Fairbanks Intertie, between Cantwell and Stevens substations.
The report is separated into two sections, the first is the electrical studies required to identify the
Railbelt improvements necessary to support the Susitna Project and the second part includes
feasibility level costs estimates for the projects identified in the studies.
3 Power Flow Base Cases and Modeling Issues
EPS created three power flow base cases, representing the 2020 winter peak, 2020 summer
peak, and 2020 summer valley load condition. Additionally, two levels of generation at Susitna
were evaluated; a 420 MW and a 600 MW level. This resulted in a total of six power flow base
cases.
The Railbelt power flow base cases used for this study are the 2015 planning cases developed
for previous studies for the Railbelt Intertie Operating Committee (IOC). The planning cases
have load levels representative of the 2020 time frame within reasonable estimates of the load
growth. The power flow model also includes various generation and transmission upgrades to
the Railbelt, expected to be in place by 2020. These improvements are outlined below.
Load Updates
The system loads were updated to a 2020 level based on load forecasts.
Generation Updates
Three combustion turbines (CTs) and one heat recovery steam generator (HRSG) generator
were added at the new International substation (ITSS) within Chugach (CEA). The generators
are configured as one stand-alone CT plus a 2x1 configuration(two CTs feeding waste heat to
one steam turbine (ST)).
Three combustion turbines and one HRSG generator were added at Eklutna substation within
MEA. The generators were configured as one stand-alone CT plus a 2x1 CT / HRSG
configuration.
Beluga unit #8 is decommissioned in the CEA area.
The Nikiski Solars units are decommissioned in the HEA area.
Transmission Updates
AEA – Susitna Hydro Transmission Study
October 22, 2009 4
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The AMLP Substation #14 (115 kV) substation was built out to remove a tapped line within the
AMLP system. The AMLP A.P.A. Switchyard (115 kV) substation was built out to remove a
tapped line within the AMLP system. Substation #15 was also reconfigured to accommodate
this change. A Fort Richardson (115 kV) substation was added with connections to Substation
#20 and Plant 2. The Fort Richardson 34.5 kV substation was modified to connect to the North
Sub substation.
CEA International Substation (138 kV) was built out to remove bus ties, reconfigure the bus
structure, add breaker positions, and remove tapped line configurations. A 138 kV transmission
line from Retherford substation to University substation was added.
A second (express) 115 kV line was added between Briggs substation and Eklutna substation,
within the MEA system.
Within HEA, the Tesoro 115 kV substation was expanded to remove a tapped line configuration
to Bernice substation. A new Tesoro load bus was added. The Bernice 115 kV substation was
built out to remove the Bernice tapped line segment. New load transformers were added at
Bernice Lake substation. The Bernice Lake – Tesoro – Marathon - Beaver Creek - Soldotna 69
kV lines and subsystem was reconfigured to incorporate a new normal operating configuration.
Sterling 115 kV and Pioneer 115 kV substations were added. A Diamond Ridge 69 kV
substation load bus was added.
Susitna Generation Upgrades
Both proposed Susitna generation options were modeled. The Susitna units were modeled as
three 140 MW units for the 420 MW cases or three 200 MW units for the 600 MW cases. This
results in the loss of one of the Susitna units becoming the single largest contingency for the
Railbelt. The capacity of the Susitna units required that the Railbelt carry at least 140 MW or
200 MW (depending on the generation scenario) of spinning reserve online. EPS created the
six power flow dispatches with this new spinning reserve requirement. Table 1 below lists the
dispatches that were used for this study.
The dispatch cases attempted to use Susitna at or near maximum as much as possible. Other
hydro resources were typically dispatched, along with the most efficient new or proposed
combustion turbines within the system.
AEA – Susitna Hydro Transmission Study
October 22, 2009 5
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Table 1 – Generation Dispatch
summer
peak
summer
valley
winter
peak
summer
peak
summer
valley
winter
peak
BES
BRADLEY LAKE 1 30.6 21.0 35.4 30.9 19.0 43.5
BRADLEY LAKE 2 27.0 20.0 35.0 27.0 15.0 43.0
TESORO 1 3.0 3.0 3.0 3.0 3.0 3.0
TESORO 2 3.0 3.0 3.0 3.0 3.0 3.0
SUSITNA 1 140.0 130.0 140.0 200.0 140.0 200.0
SUSITNA 2 140.0 130.0 140.0 200.0 140.0 200.0
SUSITNA 3 140.0 130.0 140.0 200.0 140.0 200.0
AMLP #3
AMLP #6 31.5 29.2 26.1
AMLP #7 65.0 73.4 65.7
Beluga 6 67.2
Beluga 7 63.3
ITSS #1
ITSS #2 44.0 25.0 40.8 26.5 36.5
ITSS #3 40.8 36.5
ITSS #4 10.1 5.8 18.7 12.2 16.8
COOPER 1 4.0 8.0 2.0 3.0
COOPER 2 4.0 8.0 2.0 3.0
EKLUTNA 1 7.0 16.0 4.0 8.0
EKLUTNA 1 7.0 16.0 4.0 8.0
Healy 24.6 14.0 22.8 14.8 14.0 20.4
HCCP#2-G 54.5 30.0 50.4 32.8 30.0 45.2
B MILL#1 -4.0 -4.0 -4.0 -4.0 -4.0 -4.0
B MILL#2 -4.0 -4.0 -4.0 -4.0 -4.0 -4.0
NORTH POLE 1
NORTH POLE 2
NPCC 1 36.3 42.0 21.9 38.7
NPCC 2 8.9 10.6 5.4 9.5
Total Generation 772.6 503.8 995.6 781.5 496.0 1001.9
Bus Name
Susitna at 420 MW Susitna at 600 MW
Susitna Transmission Upgrades
To accommodate the addition of the Susitna project, several transmission improvements to the
Railbelt are required. These are described below.
A new substation was added along the existing Railbelt 138 kV Northern Intertie at Gold
Creek. This is the point of interconnection for the Susitna Hydro Project.
From Gold Creek, three 230 kV lines run seven miles to the Susitna Hydro Plant.
The substation at Gold Creek intercepts the existing northern Intertie that runs between
Teeland and Healy. The existing 138 kV line from Healy to Douglas is built to a 345 kV
design, but operated at 138 kV. This section of the line will need to be converted to 230
kV operation, and was converted in the model.
AEA – Susitna Hydro Transmission Study
October 22, 2009 6
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Two additional 230 kV lines were added to the power flow model, directly connecting the
Douglas substation to the new substation at Gold Creek.
An additional 230 kV line was added from the new substation at Gold Creek to Healy.
A new 230 kV bus is required at Healy substation.
The existing 138 kV bus sections at Cantwell, Stevens, and Douglas were converted to
230 kV and the substation step down transformers were changed to 230 kV on the high
side.
The Healy to Wilson 138 kV was converted to 230 kV operation and moved to the new
230 kV Healy bus.
Two 100 MVA, 230 / 138 kV transformers were added at Wilson.
Two new static VAR compensation (SVC) devices were added to support the new
Susitna generation and transmission. A new 200 MVAR SVC was added at the new
Healy 230 kV bus and a new 200 MVAR SVC was added at the upgraded Douglas 230
kV bus.
A new 230 kV substation at Lorraine was added. This substation intersects the Pt.
MacKenzie - West Terminal – East Terminal – Plant 2 230 kV line and the Pt.
MacKenzie - Teeland 230 kV line.
A new 230 kV line from Pt. MacKenzie to Douglas was added.
A new 230 kV line from Lorraine to Douglas was added.
The study results eventually indicated that the existing Healy – Gold Hill 138 kV line will
also need to be upgraded to 230 kV operation (will require re-conductoring). This will
also necessitate the conversion of the Ester and Nenana substations from 138 kV to 230
kV, and will require adding two 100 MVA 230 / 138 kV transformers at Gold Hill.
One line diagrams showing the 2020 Railbelt system with the changes mentioned above are
included in appendix A.
4 Transient Stability Cases
Standard IEEE dynamic stability models for the generator, turbine, and excitation models of the
Susitna units were used. IEEE standard models were also used for the new SVC’s added at
Douglas and Healy.
EPS ran several line faults and unit trips to determine the impact that the new Susitna
generation would have on the Railbelt. Below is a description of the line fault and trip
contingencies run for this study.
L1. Fault on Susitna - Gold Creek 230 kV line at 1 second, near the Susitna end. Fault
cleared at 5 cycles.
L2. Fault on Gold Creek - Healy 230 kV line at 1 second, near the Gold Creek end. Fault
cleared at 5 cycles.
L3. Fault on Healy - Wilson 230 kV line at 1 second, near the Healy end. Fault cleared
at 5 cycles.
L4. Fault on Healy - Nenana 138 kV line at 1 second, near the Healy end. Fault cleared
at 5 cycles.
L5. Fault on Gold Creek - Douglas 230 kV line at 1 second, near the Gold Creek end.
Fault cleared at 5 cycles.
L6. Fault on Teeland - Douglas 230 kV line at 1 second, near the Teeland end. Fault
cleared at 5 cycles.
AEA – Susitna Hydro Transmission Study
October 22, 2009 7
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L7. Fault on Lorraine - West Terminal 230 kV line at 1 second, near the Lorraine end.
Fault cleared at 5 cycles.
L8. Fault on Pt MacKenzie - International 138 kV line at 1 second, near the Pt
MacKenzie end. Fault cleared at 5 cycles.
L9. Fault on Teeland - Cottle 115 kV line at 1 second, near the Teeland end. Fault
cleared at 6 cycles.
L10. Fault on Briggs - Plant 2 115 kV line at 1 second, near the Briggs end. Fault cleared
at 5 cycles.
L11. Fault on Plant 2 - University 230 kV line at 1 second, near the Plant 2 end. Fault
cleared at 5 cycles.
L12. Fault on University - Dave's Creek 115 kV line at 1 second, near the University end.
Fault cleared at 6 cycles.
L13. Fault on Soldotna - Quartz Creek 115 kV line at 1 second, near the Soldotna end.
Fault cleared at 6 cycles.
The following unit trip contingencies were also studied. Each scenario represents a unit trip
(unit breaker opens) event.
G1. Susitna Unit #1 during the 420 MW loading cases (140 MW trip).
G2. Susitna Unit #1 during the 600 MW loading cases (200 MW trip).
G3. AML&P Plant 2 Unit #7
G4. Bradley Lake Unit #1
G5. International Substation Unit #2
G6. Healy Clean Coal
G7. North Pole Combined Cycle Unit #1
Table 2 lists the transient stability results for each of the contingencies described above.
AEA – Susitna Hydro Transmission Study
October 22, 2009 8
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Table 2 – Transient Stability Results
summer peak summer valley w inter peak summer peak summer valley winter peak
L1
Susitna-Gold
Creek stable stable stable stable stable stable
L2
Gold Creek-
Healy stable stable stable stable stable stable
L3 Healy-Wilson unstable unstable unstable unstable unstable unstable
L3 w ith 230 kV
Healy-Goldhill
build out Healy-Wilson stable stable stable stable stable stable
L4 Healy-Nenana stable stable stable stable stable stable
L5
Gold Creek-
Douglas stable stable stable stable stable stable
L6 Teeland-Douglas stable stable stable stable stable stable
L7
Lorraine-West
Terminal stable stable stable stable stable stable
L8
Pt. MacKenzie-
International stable stable stable stable stable stable
L9 Teeland-Cottle stable stable stable stable stable stable
L10 Briggs-Plant 2 stable stable stable stable stable stable
L11
Plant 2-
University stable stable stable stable stable stable
L12
University-
Daves Creek
stable with load
shedding
stable with load
shedding
stable with load
shedding
stable with load
shedding
stable with load
shedding
stable with load
shedding
L13
Soldotna-Quartz
Creek
stable with load
shedding
stable with load
shedding
stable with load
shedding
stable with load
shedding
stable with load
shedding
stable with load
shedding
G1 Susitna #1
stable, freq at
59.1 Hz after 20
secs.
stable, freq at
60.0 Hz after 20
secs.
stable, freq at
60.0 Hz after 20
secs.
G2 Susitna #4
stable, freq at
60.0 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
stable, freq at
60.2 after 20
secs.
G3 ML&P 7
stable, freq at
60.3 Hz after 20
secs.
stable, freq at
59.6 Hz after 20
secs.
stable, freq at
59.6 Hz after 20
secs.
G4 Bradley Lake
stable, freq at
59.9 Hz after 20
secs.
stable, freq at
60.0 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
stable, freq at
60.0 Hz after 20
secs.
stable, freq at
59.8 Hz after 20
secs.
G5 ITSS #2
stable, freq at
59.8 Hz after 20
secs.
stable, freq at
60.1 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
stable, freq at
60.0 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
G6 HCCP#2-G
stable, freq at
59.6 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
stable, freq at
60.0 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
G7 NPCC
stable, freq at
59.9 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
stable, freq at
60.0 Hz after 20
secs.
stable, freq at
59.9 Hz after 20
secs.
420 MW Susitna 600 MW Susitna
Unit Trips
Line Outages
Most of the line fault contingencies analyzed showed stable results. The University - Daves
Creek and Soldotna - Quartz Creek line contingencies resulted in considerable load shedding,
which is the expected result when the Kenai Tie is opened with heavy transfers.
The results for the original L3 line contingency (fault and trip the Healy – Wilson 230 kV line)
were unstable for all of the power flow base cases. The system would go out of step and
collapse between Fairbanks and Healy along the remaining Healy – Gold Hill 138 kV line.
AEA – Susitna Hydro Transmission Study
October 22, 2009 9
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There are currently two lines connecting Healy to Fairbanks. One is the Healy - Wilson line that
was converted to 230 kV for the purposes of this study, and the other is the Healy – Gold Hill
line which remained at 138 kV in the original cases of this study. For this study, generation at
both the northern and southern ends of the Railbelt was decreased or turned off to
accommodate the new Susitna generation. This increased flow heading both north and south
along the Railbelt. When the Healy - Wilson line is faulted and tripped, the flow on the
remaining Healy – Gold Hill 138 kV line increases considerably, causing the system to go
unstable along this line.
The Healy – Gold Hill 138 kV line was upgraded to 230 kV operation and changes were made to
Nenana, Ester, and Gold Hill stations to accommodate the 230 kV operation. Two new 100
MVA, 230 / 138 kV transformers were added at Gold Hill. New transient stability cases were run
for the Healy – Wilson and Healy Gold Hill 230 kV line fault and trip contingencies. These
contingencies are stable following the upgrade of the Healy – Gold Hill line.
The addition of the Susitna Hydro plant significantly increases the size of the single largest
generation contingency within the Railbelt. All of the generation trip scenarios were stable.
For the unit trip scenarios where a Susitna unit was tripped, the Railbelt experiences significant
load shedding. This sudden large loss of generation highlights the need for the Railbelt to re-
examine the underfrequency load shedding (UFLS) scheme. In the summer peak case with 420
MW of Susitna online, when 140 MW of Susitna generation is tripped, the system frequency
hangs near 59.2 Hz after 20 seconds. This indicates that a larger kicker block of load should be
shed in order to bring the system towards 60 Hz more quickly. In the summer valley case with
600 MW of Susitna online, the trip of 200 MW of Susitna causes the system to over-shed load
and the system frequency settles at 60.2 Hz after 20 seconds. Should a large hydro project
such as Susitna be considered, especially in conjunction with other renewable energy projects
such as wind energy, strong consideration should be given to a stored energy system to provide
regulation and spinning reserve requirements.
5 Transmission Cost Estimates
The transmission improvements identified in the electrical study were estimated using a unit
cost estimate for each transmission line section. In each of the identified transmission lines, a
preliminary route was identified and an estimate of mountainous vs flat terrain was developed.
A per mile cost of mountainous transmission line construction and flat terrain construction was
developed and used for all lines included in the study.
Line routes that include more than one circuit assume a double circuit transmission line
construction. The new transmission lines between Douglas and Healy stations are assumed
constructed along the corridor of the Anchorage – Fairbanks Intertie. The construction of the
Douglas – Lorraine circuit line is assumed to be a double-circuit transmission line, with one line
continuing from Lorrain to Pt. MacKenzie station.
The conversion of the Healy – Gold Hill transmission line is assumed to be the same cost as
new construction.
All line costs are based on using twin bundled 954 kcmil conductor supported on steel H-frame
structures. A single overhead fiber optic ground wire (OPGW) and a single overhead ground
wire (OHGW) are included in the estimates. Routes are assumed to follow existing transmission
corridors, and double circuit structures are used where applicable. Costs include administration,
engineering, permitting and construction management allowances (assumed to be 15% of
AEA – Susitna Hydro Transmission Study
October 22, 2009 10
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construction cost), but do not include land acquisition costs. Following is a summary of our
estimates:
Length Avg. cost/mile Total cost
Triple circuit (one S/C and one D/C line) 12 miles $3,948k $47.4
Devils Canyon to Gold Creek
Single circuit 230kV from Gold Creek to Healy 96 miles $1,597k $153.3
Double circuit 230kV from Gold Creek to Douglas 74 miles $2,596k $192.1
Single circuit 230kV from Douglas to Teeland 26 miles $1,459k $37.9
Double circuit 230kV from Douglas to Lorraine 47 miles $2,489k $117.0
Single circuit 230kV from Lorraine to Pt. Mackenzie 5 miles $1,459k $7.3
Single circuit 230kV from Healy to Gold Hill 103 miles $1,448k $149.1
6 Conclusions
EPS has completed a high level study to evaluate the improvements required to the Railbelt
transmission system to support the proposed Susitna project. The study indicates that the
project is feasible and identified a minimum number of projects that would be required to
integrate the project into the Raibelt. Although these projects are listed as projects required to
support the Susitna project, the majority of the identified projects are not specific to the Susitna
project, but are required to strengthen the Railbelt transmission system to allow power to be
reliably transferred between load areas, irrespective of the generation source.
The transmission improvements are dependent upon the assumed power flows from Susitna
and the generation of existing Railbelt units, primarily the new ITSS plant in Anchorage and the
Bradley Lake and Cooper Lake hydro units on the Kenai. Susitna power flows different than
those assumed in the study will result in considerably different projects. In particular, increased
flows to the south and decreased energy from Bradley/Cooper Lake projects will increase the
need for transmission to the Anchorage and Kenai areas above that which is identified in this
study.
SVCs will be required at Healy and Douglas stations to control voltage and provide support for
transient stability. EPS did not determine the exact ratings for the SVCs but rather determined
that the transmission system is feasible.
There are many projects that would be required to integrate the Susitna project, or any other
large generation project with the Railbelt electrical system that cannot be identified in this study.
The control and operation of the transmission system would require improvements to the
communication system of the electric utilities as well as control and monitoring improvements,
improvements to the spinning reserve and under frequency load shedding policies.
AEA – Susitna Hydro Transmission Study
October 22, 2009 11
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Appendix A – Power Flow One Line Diagrams
301HEALY-19.0
-41.2
5.4
41.3
2.6
111.6
-8.4
-111.3
17.4
-139.9
-18.5140.0-2.6
-111.6
-11.3
112.3
-8.4
-110.9
-11.3
-8.4
-110.9
-11.3
17.4
-139.9
-18.5140.017.4
-139.9
-18.5140.0-9.2
41.5
-19.0
-41.3
-9.2
41.9
-5.5
-41.8
2.0
-38.6
-14.6
38.7
-15.8
-37.9
-6.6
38.0
SW
0.9
-10.8-5.210.8-12.315.790.738.381.3-38.6-172.056.4172.9-56.4-172.98.1173.3 SW-1.451.7 -51.7-1.4 3.6-51.7 -0.0-0.00.00.0 -0.0-0.00.00.0 -0.00.0 -7.2140.018.5 -7.218.5-140.0 -7.2140.018.5 11.6
-0.3
-11.1
0.3
8.5
173.4
-8.1-173.310.2
-33.0
-9.2
-1.7-9.91.5
9.9
-1.4
59.0
2.0-58.7-18.4
-8.2
17.0
-18.4
-8.28.3
10.2
-33.0
-9.2
33.0
-14.4
6.62.3-6.6-14.7
6.6-6.6
14.3
-50.4
-19.3
50.5
14.2-13.5
38.5
-0.1
-5.0
0.3
5.0
14.0
-106.5
-24.0
107.0
-20.1
125.2
15.3
-124.8
-25.8
96.1
13.5
-95.6
-0.0
-0.0
0.0
-0.0
-0.5
0.0
0.5
2.9-103.5-11.8
105.5
0.1
-11.5
0.1
11.5
0.1
-11.5
0.1
11.5138.0310HEALY 230230.0300CANTWELL231.6350WILSON 230228.1231.025.8R1R3790DOUGLAS230.025.01 0.0
51PT MACKZ231.578TEELAND230.5231.27901DOUGLAS25.61 231.8770TEELAND115.97701TEELAND34.21
16.3
* -30.4
-14.3
-5.3780TEELAND138.013.8S 1.2
* -0.00.0-1.250BELUGA232.5140.017.0
8.3
* 0.0
-0.0
115.3775MCRAE115.7765COTTLE231.7333SUSITNA33.0
510PT MACKZ53WEST TRM231.02.130103HEALYSVS12.5SSS 13.4
0.0
-48.4 S -0.0
49.713.1 7910DOUGSVS230S 0.0-89.9-0.0
94.8 3301SUSITNA #113.81 3302SUSITNA #213.81 3303SUSITNA #313.81 3304SUSITNA #413.91 3305SUSITNA #513.91 3306SUSITNA #613.91 140.00.0325WILSON137.2SS B 230.454EAST TRM227.156AMLP TAP52UNIVRSTY226.0202PLANT2-90.6115.6-81.2500BELUGA530WORONZOF139.4139.83101HEALYSVS 230
7951STEVENSSW
535WORONZF139.6-0.0-1.3
-54.0800LORRAINE* 35.87801TEELAND 795STEVENS30000CANTWELL3.651.7-38.5
400GOLD CREEK112.0
112.0
-140.0-140.0RAILBELT SUMMER PEAK 2020SUSITNA AT 420 MW THU, OCT 22 2009 15:32
301HEALY-12.6
-66.3
0.3
66.5
-6.1
154.0
3.6
-153.5
20.5
-199.7
-19.8200.06.1
-154.0
-11.8
155.4
3.7
-153.0
-11.8
3.7
-153.0
-11.8
20.5
-199.7
-19.8200.020.5
-199.7
-19.8200.0-13.0
66.7
-12.6
-66.4
-13.0
67.2
-0.3
-67.0
-1.0
-51.4
-11.3
51.5
-17.7
-50.4
-4.0
50.6
SW
0.4
-14.7-4.414.8-24.134.3153.835.394.1-35.3-247.878.7249.7-78.7-249.731.6250.5 SW-2.959.2 -59.2-2.9 5.8-59.2 -3.8200.019.8-200.0 -3.8200.019.8-200.0 -3.819.8 0.0-0.0-0.0 0.0-0.00.0 0.0-0.0-0.0 6.8
-0.3
-6.7
0.3
33.1
250.8
-31.6-250.57.5
-43.7
-5.9
-1.8-9.91.6
9.9
3.5
81.1
-2.1-80.6-20.4
-14.1
19.0
-20.4
-14.114.1
7.5
-43.7
-5.9
43.7
-14.3
8.62.5-8.6-14.5
8.6-8.6
5.9
-74.3
-9.9
74.6
11.4-10.4
50.0
-0.1
-5.0
0.3
5.0
1.7
-148.3
-6.3
149.2
-3.7
171.6
3.0
-170.9
-10.2
133.6
2.7
-132.8
-0.0
-0.0
0.0
-0.0
-0.5
0.0
0.5
5.8-118.3-9.5
121.0
0.0
5.9
0.0
-5.9
0.0
5.9
0.0
-5.9138.0310HEALY 230230.0300CANTWELL231.2350WILSON 230227.6230.525.8R1R3790DOUGLAS230.025.01 0.0
51PT MACKZ229.478TEELAND229.3229.17901DOUGLAS25.61 231.1770TEELAND115.17701TEELAND34.01
19.0
* -41.1
-16.5
-5.3780TEELAND138.013.8S -1.7
* -0.00.01.750BELUGA230.4138.419.0
14.1
* 0.0
-0.0
114.2775MCRAE114.9765COTTLE231.1333SUSITNA43.7
510PT MACKZ53WEST TRM228.62.230103HEALYSVS12.3SSS 13.5
0.0
-34.1 S -0.0
34.713.7 7910DOUGSVS230S -0.0-9.0-0.0
9.0 3301SUSITNA #113.91 3302SUSITNA #213.91 3303SUSITNA #313.91 3304SUSITNA #413.81 3305SUSITNA #513.81 3306SUSITNA #613.81 -0.0-200.0325WILSON137.0SS B 227.854EAST TRM223.156AMLP TAP52UNIVRSTY222.1202PLANT2-153.5112.8-93.9500BELUGA530WORONZOF137.7138.13101HEALYSVS 230
7951STEVENSSW
535WORONZF138.4200.0-1.3
-69.6800LORRAINE* 46.47801TEELAND 795STEVENS30000CANTWELL5.859.2-50.0
400GOLD CREEK154.9
154.9
0.00.0RAILBELT SUMMER PEAK 2020SUSITNA AT 600 MW THU, OCT 22 2009 15:37
301HEALY-17.9
-54.9
4.9
55.0
5.5
92.7
-12.5
-92.4
17.3
-129.9
-18.5130.0-5.5
-92.7
-11.2
93.1
-12.4
-92.1
-11.2
-12.4
-92.1
-11.2
17.3
-129.9
-18.5130.017.3
-129.9
-18.5130.0-9.2
55.2
-17.8
-55.0
-9.1
55.6
-4.9
-55.5
6.4
-30.5
-19.2
30.6
-12.1
-30.1
-10.6
30.2
SW
1.8
-8.3-6.28.4-4.37.894.526.457.9-27.0-152.435.1153.0-65.3-153.016.8153.4 SW-2.651.2 -51.2-2.6 4.7-51.2 0.0-0.0-0.00.0 0.0-0.0-0.00.0 0.0-0.0 -8.8130.018.5 -8.818.5-130.0 -8.8130.018.5 3.0
-0.2
-2.9
0.2
17.0
153.5
-16.8-153.414.0
-26.2
-13.3
-0.7-5.60.5
5.6
-5.2
48.4
5.4-48.2-22.4
-9.1
21.0
-22.4
-9.19.1
14.0
-26.2
-13.3
26.2
-15.1
4.93.0-4.9-15.4
4.9-4.9
12.8
-45.3
-18.0
45.4
17.1-16.6
29.4
-0.1
-2.9
0.1
2.9
15.0
-89.9
-26.7
90.3
-25.1
102.8
18.9
-102.5
-28.8
80.8
15.1
-80.5
-0.0
-0.0
0.0
-0.0
-0.5
0.0
0.5
5.2-102.3-14.6
104.3
0.0
2.8
0.0
-2.8
0.0
2.8
0.0
-2.8138.0310HEALY 230230.0300CANTWELL231.6350WILSON 230229.1231.125.8R1R3790DOUGLAS230.025.01 0.0
51PT MACKZ231.978TEELAND230.9231.57901DOUGLAS25.51 231.9770TEELAND116.27701TEELAND34.41
13.5
* -24.6
-12.3
-3.0780TEELAND138.013.8S 2.2
* 0.0-0.0-2.250BELUGA233.1140.621.0
9.1
* 0.0
0.0
115.9775MCRAE116.1765COTTLE231.8333SUSITNA26.2
510PT MACKZ53WEST TRM231.32.730103HEALYSVS12.1SSS 13.4
0.0
-48.9 S -0.0
50.312.9 7910DOUGSVS230S 0.0-110.2-0.0
117.8 3301SUSITNA #113.81 3302SUSITNA #213.81 3303SUSITNA #313.81 3304SUSITNA #413.91 3305SUSITNA #513.91 3306SUSITNA #613.91 130.00.0325WILSON137.8SS B 230.854EAST TRM228.456AMLP TAP52UNIVRSTY227.7202PLANT2-94.4116.7-57.8500BELUGA530WORONZOF140.3140.53101HEALYSVS 230
7951STEVENSSW
535WORONZF140.0-0.0-0.7
-34.2800LORRAINE* 27.67801TEELAND 795STEVENS30000CANTWELL4.751.2-29.4
400GOLD CREEK92.8
92.8
-130.0-130.0RAILBELT SUMMER VALLEY 2020SUSITNA AT 390 MW THU, OCT 22 2009 15:33
301HEALY-16.5
-54.9
3.5
55.0
3.0
102.5
-9.4
-102.3
19.2
-139.9
-20.2140.0-3.0
-102.5
-12.2
103.2
-9.4
-102.0
-12.2
-9.4
-102.0
-12.2
19.2
-139.9
-20.2140.019.2
-139.9
-20.2140.0-10.5
55.2
-16.5
-55.0
-10.4
55.6
-3.6
-55.5
1.6
-36.5
-14.2
36.6
-16.2
-36.1
-6.1
36.2
SW
0.7
-10.3-5.010.4-3.97.494.136.772.9-37.0-167.046.1167.8-76.0-167.828.0168.2 SW-2.651.2 -51.2-2.6 4.7-51.2 -12.3140.020.2-140.0 -12.3140.020.2-140.0 -12.320.2 0.00.00.0 0.00.00.0 0.00.00.0 3.0
-0.2
-2.9
0.2
28.4
168.3
-28.0-168.29.8
-31.2
-9.0
-0.7-5.60.5
5.6
-3.4
50.7
3.7-50.5-21.0
-7.8
19.6
-21.0
-7.87.8
9.8
-31.2
-9.0
31.2
-14.3
5.92.4-5.9-14.6
5.9-5.9
6.7
-52.8
-11.6
52.9
16.1-15.6
30.7
-0.1
-2.9
0.1
2.9
7.0
-100.0
-17.8
100.5
-17.6
112.6
12.0
-112.3
-20.6
90.3
7.6
-89.9
-0.0
-0.0
0.0
-0.0
-0.5
0.0
0.5
5.2-102.3-14.6
104.3
0.0
2.8
0.0
-2.8
0.0
2.8
0.0
-2.8138.0310HEALY 230230.0300CANTWELL231.5350WILSON 230229.1231.025.8R1R3790DOUGLAS230.025.01 0.0
51PT MACKZ230.978TEELAND230.4230.57901DOUGLAS25.51 231.6770TEELAND115.97701TEELAND34.31
14.3
* -25.7
-13.1
-3.0780TEELAND138.013.8S 0.9
* -0.00.0-0.950BELUGA231.9139.519.6
7.8
* 0.0
-0.0
115.5775MCRAE115.8765COTTLE231.5333SUSITNA31.2
510PT MACKZ53WEST TRM230.12.130103HEALYSVS12.1SSS 13.4
0.0
-46.4 S -0.0
47.613.2 7910DOUGSVS230S -0.0-80.20.0
84.1 3301SUSITNA #113.91 3302SUSITNA #213.91 3303SUSITNA #313.91 3304SUSITNA #413.81 3305SUSITNA #513.81 3306SUSITNA #613.81 0.0-140.0325WILSON137.8SS B 229.654EAST TRM226.756AMLP TAP52UNIVRSTY225.7202PLANT2-94.0115.8-72.8500BELUGA530WORONZOF139.0139.43101HEALYSVS 230
7951STEVENSSW
535WORONZF139.2140.0-0.7
-44.1800LORRAINE* 28.87801TEELAND 795STEVENS30000CANTWELL4.751.2-30.7
400GOLD CREEK102.8
102.8
0.00.0RAILBELT SUMMER VALLEY 2020SUSITNA AT 420 MW THU, OCT 22 2009 15:33
301HEALY-15.4
-71.4
3.3
71.6
5.4
91.6
-12.4
-91.4
17.9
-139.9
-18.9140.0-5.4
-91.6
-11.4
92.1
-12.4
-91.1
-11.4
-12.4
-91.1
-11.4
17.9
-139.9
-18.9140.017.9
-139.9
-18.9140.0-9.8
71.7
-15.3
-71.4
-9.8
72.2
-3.2
-72.0
2.4
-48.3
-15.1
48.4
1.9
-46.5
-24.4
46.7
SW
8.1
-36.0-10.236.3-22.927.7106.828.391.4-28.5-198.260.3199.3-60.3-199.312.1199.8 SW-4.269.7 -69.7-4.2 8.2-69.7 0.00.0-0.0-0.0 0.00.0-0.0-0.0 0.0-0.0 -7.7140.018.9 -7.718.9-140.0 -7.7140.018.9 10.9
-0.3
-10.5
0.3
12.9
200.0
-12.1-199.815.7
-29.5
-14.8
-3.3-15.33.2
15.3
8.6
71.3
-7.5-70.8-19.6
-49.0
18.3
-19.6
-49.049.0
15.7
-29.5
-14.8
29.5
-8.5
-44.5-2.444.7-8.8
-44.644.8
16.2
-19.9
-21.8
20.0
7.6-6.6
49.4
-0.2
-7.8
0.6
7.8
10.0
-82.1
-22.4
82.4
-11.4
115.2
5.9
-114.9
-25.2
68.2
10.3
-68.0
-0.0
-0.0
0.0
0.1
-0.5
-0.1
0.5
8.4-139.5-3.1
143.2
0.0
-0.2
0.0
0.2
0.0
-0.2
0.0
0.2138.0310HEALY 230230.0300CANTWELL231.6350WILSON 230226.0231.125.9R1R3790DOUGLAS230.025.01 0.0
51PT MACKZ231.578TEELAND230.0231.17901DOUGLAS25.51 231.9770TEELAND115.37701TEELAND34.01
22.6
* -37.3
-19.3
-8.2780TEELAND138.013.8S -0.1
* -0.0-0.00.150BELUGA232.9140.618.3
49.0
* 0.0
-0.0
114.3775MCRAE115.0765COTTLE231.7333SUSITNA29.5
510PT MACKZ53WEST TRM230.8-2.730103HEALYSVS12.5SSS 13.5
0.0
-33.1 S -0.0
33.813.1 7910DOUGSVS230S -0.0-90.50.0
95.6 3301SUSITNA #113.81 3302SUSITNA #213.81 3303SUSITNA #313.81 3304SUSITNA #413.91 3305SUSITNA #513.91 3306SUSITNA #613.91 140.0-0.0325WILSON136.3SS B 230.254EAST TRM226.656AMLP TAP52UNIVRSTY225.7202PLANT2-106.6114.8-91.3500BELUGA530WORONZOF140.3140.43101HEALYSVS 230
7951STEVENSSW
535WORONZF139.70.0-2.0
-56.1800LORRAINE* 45.67801TEELAND 795STEVENS30000CANTWELL8.269.7-49.3
400GOLD CREEK91.8
91.8
-140.0-140.0RAILBELT WINTER PEAK 2020SUSITNA AT 420 MW THU, OCT 22 2009 15:34
301HEALY-11.1
-78.2
-0.5
78.4
-4.8
146.2
1.6
-145.7
20.8
-199.7
-20.2200.04.8
-146.2
-12.2
147.5
1.6
-145.2
-12.2
1.6
-145.2
-12.2
20.8
-199.7
-20.2200.020.8
-199.7
-20.2200.0-13.0
78.6
-11.0
-78.1
-13.0
79.1
0.6
-78.9
1.6
-47.1
-14.3
47.2
1.0
-45.4
-23.5
45.6
SW
3.8
-12.7-7.912.7-21.327.0116.125.4103.8-25.3-219.958.3221.2-58.3-221.210.2221.9 SW-4.672.0 -72.0-4.6 8.9-72.0 -4.2200.020.2-200.0 -4.2200.020.2-200.0 -4.220.2 -0.00.00.0 -0.00.0-0.0 -0.00.00.0 10.0
-0.3
-9.6
0.3
11.3
222.1
-10.2-221.917.0
-40.0
-15.6
-3.3-15.33.2
15.3
7.4
84.0
-5.8-83.4-24.4
-13.2
23.0
-24.4
-13.213.2
17.0
-40.0
-15.6
40.0
-15.5
8.13.5-8.1-15.8
8.1-8.1
21.4
-58.6
-26.0
58.8
8.2-6.9
56.0
-0.2
-7.8
0.6
7.8
16.2
-137.0
-22.5
137.8
-12.1
167.1
11.0
-166.4
-25.4
123.5
16.4
-122.8
-0.0
-0.0
0.0
0.1
-0.5
-0.1
0.5
9.2-144.0-1.8
147.9
0.0
4.2
0.0
-4.2
0.0
4.2
0.0
-4.2138.0310HEALY 230230.0300CANTWELL231.2350WILSON 230225.7230.625.8R1R3790DOUGLAS230.025.01 0.0
51PT MACKZ231.478TEELAND229.9230.97901DOUGLAS25.51 231.2770TEELAND115.27701TEELAND34.01
22.3
* -43.4
-18.8
-8.2780TEELAND138.013.8S -0.3
* 0.00.00.350BELUGA232.5140.623.0
13.2
* 0.0
0.0
114.2775MCRAE115.0765COTTLE231.1333SUSITNA40.0
510PT MACKZ53WEST TRM230.63.230103HEALYSVS12.4SSS 13.6
0.0
-23.6 S -0.0
23.913.4 7910DOUGSVS230S -0.0-52.80.0
54.4 3301SUSITNA #113.91 3302SUSITNA #213.91 3303SUSITNA #313.91 3304SUSITNA #413.81 3305SUSITNA #513.81 3306SUSITNA #613.81 0.0-200.0325WILSON136.2SS B 229.954EAST TRM226.356AMLP TAP52UNIVRSTY225.5202PLANT2-115.9114.7-103.7500BELUGA530WORONZOF140.3140.43101HEALYSVS 230
7951STEVENSSW
535WORONZF139.7200.0-2.0
-52.4800LORRAINE* 51.77801TEELAND 795STEVENS30000CANTWELL8.972.0-55.9
400GOLD CREEK147.0
147.0
-0.0-0.0RAILBELT WINTER PEAK 2020SUSITNA AT 600 MW THU, OCT 22 2009 15:34
AEA – Susitna Hydro Transmission Study
October 22, 2009 12
The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.
Appendix B – Stability Plots
AEA – Susitna Hydro Transmission Study
October 22, 2009 13
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Appendix C – Transmission Structures
13.5 9.0 11.0 11.5
11.5 11.0 9.0 13.5
20.0
105.0
14.0
20.0
40.0
20.0
XY
Z
Dryden & LaRue, Inc., Project: "tdc_900"
PLS-POLE Version 10.06, 9:51:33 PM Thursday, October 01, 2009
Undeformed geometry displayed
40.0
20.0
12.0
13.0
12.5 10.0 10.0 12.5
20.0
85.0
8.0
XY
Z
Dryden & LaRue, Inc., Project: "tsc_900"
PLS-POLE Version 10.06, 9:56:09 PM Thursday, October 01, 2009
Undeformed geometry displayed