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HomeMy WebLinkAboutSuWa193Alaska Resources Library & Information Services 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 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. SUMMARY OF CHANGES Revision Number Revision Date Revision Description 0 Oct 22, 2009 Initial Release AEA – Susitna Hydro Transmission Study October 22, 2009 iii 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. 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 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. 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 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.  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 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. 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 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. 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 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. 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 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.  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 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. 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 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. 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 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. 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 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. 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 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 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 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 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