Alaska Village Electric Cooperative Cosmos Hills Hydropower Study

176 Pages·2010·9.74 MB·English

Alaska Village Electric Cooperative
Cosmos Hills Hydropower Study:
Reconnaissance Report
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Looking towards Cosmos Hills In late March
(photo by Ella Sakeagakl
September 22, 2010
Prepared for:
Alaska Village Electric Cooperative
4831 Eagle Street
Anchorage, Alaska 99503-7497
Prepared by:
WHPacific, Inc.
st
300 W. 31 Ave
Anchorage, AK 99503
www.whpacific.com
Funded in part by: Alaska Energy Authority Renewable Energy Fund
Grant #2195413
Executive Summary
( The Cosmos Hills-area hydropower sites of Dahl Creek, Wesley Creek, Cosmos Creek, and Kogoluktuk
River appear to be attractive economically and environmentally to develop, and are recommended for
further study. With estimated capacities ranging between 430 kW and 3,200 kW, these three sites are
the most appropriately scaled for the energy needs of Shungnak, Kobuk and Ambler, and are located
relatively close to existing road and power line infrastructure. The three other potential run-of-river
hydroelectric sites evaluated (Shungnak River, Jade Creek-East Fork near Ambler, and Canyon Creek near
Kiana), have been excluded from further consideration because the expected installation cost is too high
compared to the expected energy generated.
Dahl Creek:
• The Dahl Creek project, with an estimated 430 kW of installed capacity (well above the
Shungnak-Kobuk system's peak load of about 350 kW), could serve the combined electric loads
of Shungnak and Kobuk for about half the year.
• The installation cost of the 430-kW Dahl Creek project is estimated to be $10.3 million in 2010
dollars (including 2 miles of new power line to connect to the existing Shungnak-Kobuk power
line).
• The hydroelectric plant site is located near the existing Dahl Creek airstrip, and Kobuk-Bornite
road, which provides convenient access to Kobuk.
• The Dahl Creek site is recommended for further study due to its projected energy output, and
relative proximity to electric load/existing infrastructure. During the summer 2010 field season,
a new stream gauge will be installed on Dahl Creek, the aerial photography and LlDAR mapping
will be done of the proposed project area, studies will be conducted on wetlands and fisheries
habitat, and geotechnical conditions/hazards.
Wesley Creek:
• The Wesley Creek project, with an estimated 480 kW of capacity (well above the Shungnak
Kobuk system's peak load of about 350 kW), could serve the combined electric loads of
Shungnak and Kobuk for about half the year.
• The Wesley Creek site is located about 5 miles northwest of Kobuk.
• The installation cost of the 480-kW Wesley Creek project is estimated to be $13 million in 2010
dollars (including 1.7 miles of new power line to connect to the existing Shungnak-Kobuk power
line).
• The Wesley Creek site is very accessible due to its location along the existing road to Bornite,
and the powerhouse site would be located less than 2 miles from the existing Shungnak-Kobuk
power line.
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AVEC Cosmos Hills Hydropower Page i 22 September 2010
• The Wesley Creek site is recommended for further study due to its projected energy output, and
relative proximity to electric load/existing infrastructure. During the summer 2010 field season,
a new stream gauge will be installed on Wesley Creek, the aerial photography and LlDAR
( mapping will be done of the proposed project area, studies will be conducted on wetlands and
fisheries habitat, and geotechnical conditions/hazards.
Cosmos Creek:
• The Cosmos Creek project, with an estimated 950 kW of installed capacity (well above the 660
kW combined peak load of Ambler, Shungnak and Kobuk) and about 31 miles of new power line,
could serve the combined electric loads of Ambler, Shungnak and Kobuk for about half the year.
• The Cosmos Creek site is located about 7 miles north of Shungnak.
• The installation cost of the 9S0-kW Cosmos Creek project is estimated to be $16.3 million in
2010 dollars (including 8 miles of new power line to connect to Shungnak). The total estimated
cost of a project with an additional 23 miles of power line that would jointly serve Ambler,
Shungnak and Kobuk would be $25.3 million.
• The Cosmos Creek site presently has limited accessibility. Approximately 8 miles of new road
and power line would have to be constructed to connect the site to Shungnak.
• The Cosmos Creek site is recommended for further study due to its projected energy output,
and relative proximity to electric load/existing infrastructure. During the summer 2010 field
season, a new stream gauge will be installed on Cosmos Creek, the aerial photography and
LlDAR mapping will be done of the proposed project area, studies will be conducted on wetlands
and fisheries habitat, and geotechnical conditions/hazards.
Kogoluktuk River:
• The estimated capacity of the Kogoluktuk River run-of-river site is up to 3.2 MW (well above the
Shungnak-Kobuk system's peak load of about 350 kW), and could serve the combined electric
loads of Ambler, Shungnak and Kobuk for most of the year. A run-of-river Kogoluktuk
hydroelectric project would not necessarily need to be built up to a capacity of 3.2 MW, as
proposed by the 2006 study by Shaw, Stone & Webster. A smaller installation could be built at
the site, more optimized to local community electric loads. Area residents report that the
cascade of the Kogoluktuk River near Kobuk flows all year long, which means that some water
could be available for run-of-river hydroelectric generation when other streams are frozen.
• The Kogoluktuk River site is located about 7 miles northeast of Kobuk.
• The installation cost of a 3.2 MW Kogolukutuk River run-of-river project is estimated to be $32
million in 2010 dollars (not including the new access road and power line).
• The Kogoluktuk River site presently has limited accessibility. Approximately 8.5 miles of new
road and power line would have to be constructed to connect the site to Kobuk.
AVEC COSIllOS Hills Hydropower Page ii 22 September 2010
• The Kogoluktuk River site is recommended for further study due to its projected energy output,
and potential ability to produce hydropower for more than half the year. During the summer
2010 field season, a new stream gauge will be installed on the Kogoluktuk River, and the aerial
( photography and L1DAR mapping will be done of the proposed project area.
Shungnak River:
• The Shungnak run-of-river project, with an estimated 5.8 MW of installed capacity, could serve
the combined electric loads of Ambler, Shungnak and Kobuk for most of the year. A smaller
installation could be built at the site, more optimized to local community electric loads.
• The Shugnak River hydroelectric site is located about 9 miles northwest of the community of
Shungnak.
• The installation cost of a 5.8 MW Shungnak River run-of-river project is estimated to be $58
million in 2010 dollars (not including the new access road and power line).
• The Shungnak River site presently has limited accessibility. Approximately 11.5 miles of new
road and power line would have to be constructed to connect the site to Shungnak.
• The Shungnak River run-of-river hydropower site is not recommended for further study because
of its limited accessibility, and greater distance to a community electric load compared to the
four other hydropower sites near Shungnak and Kobuk. The Shungnak River also has a smaller
watershed, and thus less expected year-round flow, compared to the Kogoluktuk River.
Jade Creek -East Fork:
• The Jade Creek-East Fork project, with an estimated 105 kW of installed capacity, could partially
serve of the electric load of Ambler for about half the year.
• The Jade Creek-East Fork is located about 9 miles northwest of the community of Ambler.
• The Jade Creek-East Fork site presently has limited accessibility. Approximately 9 miles of new
road and power line would have to be constructed to connect the site to Ambler.
• The Jade Creek-East Fork hydropower site is not recommended for further study because of its
small estimated generation capacity, limited accessibility, and relatively long distance to a
community electric load.
Canyon Creek (Kiana):
• The Canyon Creek project, with an estimated 150 kW of installed capacity, could partially serve
of the electric load of Kiana for about half the year.
• The Canyon Creek site is located about 8 miles northeast of the community of Kiana.
AVEC Cosmos Hills Hydropower Page iii 22 September 2010
• The Canyon Creek site presently has limited accessibility. Approximately 10 miles of new road
and power line would have to be constructed to connect the site to Kiana, would require a
crossing of the Squirrel River.
(
• The Canyon Creek hydropower site is not recommended for further study because of its small
estimated generation capacity, limited accessibility, and relatively long distance to a community
electric load.
(
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AVEC Cosmos Hills Hydropower Page iv 22 September 2010
Contents
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Executive Summary ........................................................................................................................................ i
1. Introduction .......................................................................................................................................... 1
Existing Energy Scenario ........................................................................................................................... 2
Future Energy Demand Trends in the Cosmos Hills Area ......................................................................... 4
Project Benefits ......................................................................................................................................... 6
Project Risks .............................................................................................................................................. 7
2. Hyd roelectric Si te Descri ptions ............................................................................................................. 9
Dahl Creek ........................................................................................................................................... 12
Wesley Creek ...................................................................................................................................... 14
Cosmos Creek ...................................................................................................................................... 16
Jade Creek - East Fork ......................................................................................................................... 18
Canyon Creek (Kiana) .......................................................................................................................... 20
Sh ungna k Rive r .................................................................................................................................... 22
Kogoluktuk River ................................................................................................................................. 24
3. Design Considerations ......................................................................................................................... 27
( Civil Works .............................................................................................................................................. 27
Dam or Weir ........................................................................................................................................ 28
Silt Basin/Forebay Tank ....................................................................................................................... 30
I nta kelT rash rack ................................................................................................................................. 31
Penstock .............................................................................................................................................. 32
Tailrace ................................................................................................................................................ 33
Powerhouse .......................................•.............•..........•...........••.................................•............................ 33
Turbi ne and Generator ....................................................................................................................... 34
Governing a nd Electronic Control Systems ............................ " ........................................................... 35
Electric Power Tra nsm ission/Distribution .............................................................................................. 35
Access Roads and Other Infrastructure .................................................................................................. 36
Operation and Maintenance Considerations .......................................................................................... 36
Ice Problems and Mitigation Measures .................................................................................................. 36
Induced Ice Cover Formation .......................................................................... """'"'''' ....................... 37
Mechanica I Ice Removal ..................................................................................................................... 37
AVEC Cosmos Hills Hydropower Page v 22 September 2010
Prevention of Ice Accumulation on Intake Trashrack ......................................................................... 37
Penstock Icing ..................................................................................................................................... 38
( Frozen Ground Issues .......................................................................................................................... 38
4. Preliminary Project Cost Estimates ..................................................................................................... 39
5. Economic Analysis ............................................................................................................................... 40
6. Land Ownership .................................................................................................................................. 41
7. Environmental Requirements ............................................................................................................. 43
Environmental Permits ........................................................................................................................... 43
FERC Licensing Requirements ............................................................................................................. 43
FERC Licensing Exemptions ................................................................................................................. 44
Summer 2010 Environmental Studies .................................................................................................... 45
Office-Based Wetlands Delineation .................................................................................................... 45
Fisheries and Aquatic Resources Study ............................................................................................... 45
Office-Based Cultural Resources Study ............................................................................................... 45
8. Public Outreach ................................................................................................................................... 46
9. Conclusions and Recommendations ................................................................................................... 48
10. References .......................................................................................................................................... 50
Table 1: Electricity consumption in the Upper Kobuk communities (FY2008 PCE report) ........................... 3
Table 2: Delivered fuel prices for electricity generation in Upper Kobuk (2009 AVEC data) ...................... .4
Table 3: Potential run-of-river hydropower sites in the Upper Kobuk region ............................................ 10
Table 4: USGS stream flow data for Dahl Creek .......................................................................................... 10
Table 5: Run·of-river hydropower site selection decision matrix ............................................................... 11
Table 6: Dahl Creek site estimates .............................................................................................................. 13
Table 7: Cosmos Creek site estimates ......................................................................................................... 17
Table 8: Wesley Creek site estimates ......................................................................................................... 15
Table 9: Jade Creek-East Fork site estimates .............................................................................................. 19
Table 10: Canyon Creek site estimates ....................................................................................................... 21
Table 11: Proposed Shungnak river hydroelectric alternatives (Shaw Stone & Webster, 2006) ............... 22
Table 12: Proposed Kogoluktuk River hydroelectric alternatives (Shaw Stone & Webster, 2006) ............ 24
Table 13: Turbine-generator unit price quotes from Canyon Hydro (March 2010, not incl. shipping from
Seattle) ........................................................................................................................................ 34
Table 14: Power line cost estimates for Cosmos Hills projects (assumed installed cost of power lines:
$400,000/mile) ........................................................................................................................... 36
Table 15: Potential costs of Upper Kobuk hydroelectric concepts ............................................................. 39
Table 16: Preliminary Results of HOMER economic model for Dahl and Cosmos hydropower sites ......... 40
AVEC Cosmos Hills Hydropower Page vi 22 September 2010
Figure 1: Location of possible hydroelectric sites in the Shungnak-Kobuk area (map by Paula Hansen) .... 9
( Figure 2: Google Earth perspective of proposed Dahl Creek hydroelectric site ......................................... 12
Figure 3: Topo map of proposed Dahl Creek hydroelectric site (map by Paula Hansen) ........................... 13
Figure 4: Google Earth perspective of proposed Cosmos Creek hydroelectric site ................................... 16
Figure 5: Topo map of proposed Cosmos Creek hydroelectric site (map by Paula Hansen) ...................... 17
Figure 6: Google Earth perspective of proposed Wesley Creek hydroelectric site .................................... 14
Figure 7: Topo map of proposed Wesley Creek hydroelectric site (map by Paula Hansen) ....................... 15
Figure 8: Google Earth perspective of proposed Jade Creek East Fork hydroelectric site, and power line
connecting to Ambler ................................................................................................................. 18
Figure 9: Topo map of proposed Jade Creek-East Fork hydroelectric site (map by Paula Hansen) ........... 19
Figure 10: Google Earth perspective of proposed Canyon Creek hydroelectric site, and power line
connecting to Kiana .................................................................................................................... 20
Figure 11: Topo map of proposed Canyon Creek hydroelectric site (map by Paula Hansen) .................... 21
Figure 12: Topo map of proposed Shungnak River hydroelectric site (map by Polarconsult Alaska, Inc.) 23
Figure 13: Topo map of proposed Kogoluktuk River hydroelectric site (map by Polarconsult Alaska, Inc.)
.................................................................................................................................................... 25
Figure 14: Kogoluktuk River (photo by Doug Vaught) ................................................................................ 26
Figure 15: Kogoluktuk River (photo by Doug Vaught) ................................................................................ 26
Figure 16: Typical layout of a small-scale, run-of-river hydroelectric plant (drawing by Jason McGrew) .27
Figure 17: Diagram of typical diversion weir and intake structure for a small hydroelectric plant (drawing
by Brian Vanity) ........................................................................................................................... 28
Figure 18: Looking upstream at intake/diversion structure, with inflatable dam inflated, of the Power
Creek hydroelectric plant near Cordova, Alaska (photo courtesy of Cordova Electric
Cooperative) ............................................................................................................................... 29
Figure 19: Looking downstream at intake structure, with inflatable dam deflated, during the
construction of the Power Creek hydroelectric plant near Cordova, Alaska (photo courtesy of
Cordova Electric Cooperative) .................................................................................................... 29
Figure 20: Diversion weir and intake structure under construction at the Kasidaya Creek hydroelectric
plant near Skagway, Alaska (photo courtesy of Alaska Power & Telephone Company) ............ 30
Figure 21: Side-view diagram of forebay tank consisting of silt basin and trashrack (drawing by Brian
Vanity) ......................................................................................................................................... 31
Figure 22: Intake screens and pipe for the Black Bear Lake hydroelectric plant on Prince of Wales Island,
Alaska (photo courtesy of Alaska Power & Telephone Company) ............................................ 32
Figure 23: Penstock under construction for McRoberts Creek hydroelectric plant (photo courtesy of
Polarconsult Alaska, Inc.) ............................................................................................................ 33
Figure 24: Small concrete powerhouse structure for 100-kW McRoberts Creek hydroelectric plant.
(photo courtesy of Polarconsult Alaska, Inc.) ............................................................................. 33
Figure 25: Turbine-generator set for 100-kW McRoberts Creek plant (photo courtesy of Polarconsult
Alaska, Inc.) ................................................................................................................................. 34
Figure 26: Possible hydroelectric sites and power line routes (map by Paula Hansen) ............................. 35
(
AVEC Cosmos Hills Hydropower Page vii 22 September 2010
Figure 27: Land ownership of possible hydroelectric sites and power line routes, with the Cosmos and
Dahl sites labeled (map by Paula Hansen) .................................................................................. 41
Figure 28: Land ownership of possible hydroelectric sites and power line routes, closer view of Cosmos
(
Hills area (map by Paula Hansen) .............................................................................................. 42
Figure 29: Public meeting in Ambler, March 24, 2010 (photo by Elia Sakeagak) ....................................... 46
Figure 30: Public meeting in Shungnak, March 24, 2010 (photo by Elia Sakeagak) ................................... 47
Figure 31: Public meeting in Kobuk, 25 March 2010 (photo by Eva Harvey) ............................................ .47
Appendices
Appendix A: Proposed Summer 2010 Work Plan
• Hydrology
• Mapping/surveying
• Geotechnical and hazards review
• Wetlands study
• Fish and fish habitat survey
• Cultural resources office study
Appendix B: Public Meeting Minutes; Ambler, Shungnak and Kobuk, March 24-25, 2010
Appendix C: Cosmos Hills Hydroelectric Feasibility Study FERC Requirements and Field Study
Recommendations by Robin Reich of Solstice Alaska Consulting, Inc.
• Attachment A: Fish Stream Information
• Attachment B: Agency and Stakeholder Contacts
Appendix D: Preliminary Project Cost Estimates by Chuck Clark of NANA WorleyParsons
• Dahl Creek
• Cosmos Creek
Appendix E: Federal Energy Regulatory Commission, Issued Preliminary Permits prepared by
Daniel Hertrich of Polarconsult Alaska, Inc.
• Shungnak River
• Kogoluktuk River
Appendix F: HOMER Computer Models of Hydroelectric Site Economics
• Dahl Creek
• Cosmos Creek
AVEC Cosmos Hills Hydropower Page viii 22 September 2010
1. Introduction
(
The Alaska Village Electric Cooperative (AVEC) is embarking on a Resource Assessment/Feasibility
Analysis/Conceptual Design project for a regional evaluation of potential hydropower sites and
associated transmission lines in the Kobuk River Valley, in collaboration with NANA Regional
Corporation. Seven sites are under evaluation for their hydroelectric potential. The Cosmos Hills group
of projects will potentially serve the communities of Kobuk, Shungnak and Ambler. Canyon Creek near
Kiana is also being evaluated.
Currently, diesel-fuel power generation is the only source of electricity for the upper Kobuk River
communities of Ambler, Shungnak, and Kobuk. Possible renewable energy resources known to exist in
the area are wind, hydroelectric, and biomass energy. Wind energy resources for the region are already
being assessed by NANA and potential sites for small-scale run-of-river hydroelectric plants, which do
not have a water storage dam, are worthy of exploration. Run-of-river hydroelectric plants do not
require a large dam, and rely on the natural flow volume of the stream or river. Such facilities tend to
have far less environmental impacts compared to conventional dam-storage hydroelectric plants
because of the lack of a large artificial reservoir. With proper siting, construction techniques, and
operation and maintenance, run-of-river hydropower in the upper Kobuk River region could have
minimal impacts on fisheries and other subsistence resources.
The purpose of small hydroelectric plants would be to displace diesel fuel used for power generation.
Hydroelectric power plants are expensive to build, but have no fuel costs. Run-of-river hydro sites in this
area could provide electricity from about mid-April until early November. The challenge is that the peak
time of demand for electricity is winter, when the hydro plants would be producing no power. If the
hydro sites near Ambler, Shungnak and Kobuk prove viable, they will produce stable-priced power for
the long term, for about half the year. The projects, if viable, would come online in 2013 at the soonest,
assuming funding is available. A properly designed and well built hydro plant can last 50 years or more.
In 1979, the Alaska Power Administration (then a part of the US Department of Energy) conducted a
small hydropower evaluation study of AVEC-served villages, which identified Jade Creek near Ambler,
and Cosmos Creek near Shungnak as potential hydro sites. In 1981, the US Army Corps of Engineers,
Alaska District hired consultants to further evaluate small hydro power sites in Northwest Alaska. This
study further evaluated Jade Creek, Cosmos Creek, and Dahl Creek near Kobuk, and Canyon Creek near
Kiana. The 2006 Shaw Stone & Webster study for NovaGold conducted an initial evaluation of hydro
power potential to support facilities infrastructure and mining operations at the proposed mine north of
the Cosmos Hills. The 2006 study also looked at Cosmos and Dahl creeks, and proposed three
alternatives each for developing the Shungnak and Kogoluktuk rivers, including proposals for dams. Due
to these very high construction costs and possible environmental concerns, AVEC is not looking at
exploring the dam proposals expressed in the 2006 Shaw Stone & Webster report. However, AVEC,
NANA and other regional stakeholders are interested in further study and evaluation of the run-of-river
option at the Kogoluktuk site proposed by the 2006 study. This is because the river has much greater
flow volume than the creeks closer to Shungnak and Kobuk, and thus could offer an annual hydropower
generation season longer than six months.
AVEC Cosmos Hills Hydropower Page 1 22 September 2010