HomeMy WebLinkAboutCity of Atka Chuniixsax Creek Hydro Case Study - Aug 2015 - REF Grant 2195376Atka, Alaska
Hydro project displaces 85% of diesel fuel in fi rst year
Quick Facts
Total Project Costs: $5,000,000
Funding: Renewable Energy Fund, Denali Com-
mission funding, & local matching funds
Capital Costs
Design: $600,000
Construction: $4,400,000
Projects Specs
Gen. Set Make/Model: Ossberger Cross Flow
Output: 284 kW
Hydraulic Capacity: 18 cubic feet per second (cfs)
Reservoir Storage Volume: 73.8 acre feet
Static Head: 169.2 feet
Annual Energy Generation: 1,757,412 Kwh
Diesel Fuel Off set
Estimated Annual: 27,280 gallons
Actual Annual: 22,000 gallons
2012-2014: 52,000 gallons
Fuel Savings
Estimated Annual: $150,000
Actual Annual: $121,000
2012-2014: $284,000
Benefi t/Cost Ratio: 4.09
Chuniixsax Creek Hydroelectric Project
Project Overview
In partnership with the Alaska Energy Authority
(AEA), the City of Atka completed the fi nal design,
permitting, and construction of a hydroelectric dam
on Chuniixsax Creek. New transmission lines from
the powerhouse to the city were constructed in ad-
dition to new diesel plant controls and interface. Th e
powerhouse now provides up to 284 kW of renewable
energy to the community for nine to ten months of
each year. It is able to meet residential and public
facility needs and also supplies a portion of energy
needed by Atka Pride Seafoods during the summer
months.
Objectives
Th e main objectives of this project were to reduce
electrical costs to the City of Atka by using a renew-
able resource and to reduce residents’ dependency on
expensive and volatile diesel fuel.
Economic Feasibility
Th e project became operational in December of 2012.
Since then it has generated 676 MWh of electricity
and displaced 52,000 gallons of diesel fuel. Th is dis-
placement has saved the community of Atka $284,000
in energy costs. Over its projected 50 year lifespan,
the project has a calculated benefi t/cost ratio of 4.09,
meaning that the benefi ts outweigh the costs by 4.09.
Project Specifi cations
Th e powerhouse is located in the center of town and
contains 3 diesel generators that remain as a backup
power source if the load from the dam is insuffi cient.
Th e construction of the 12.5 feet high concrete dam,
952 feet of HDPE, and 50 feet of steel penstock were
undertaken by the City of Atka acting as the prime
contractor. Local labor was supplemented by import-
ed personnel possessing special skills in construction.
Chuniixsax Creek powerhouse, photo courtesy of Michael Dahl.
fuel in first year
Th e Atka Electric Utility runs the powerhouse and
does daily maintenance and inspection on plant output
and performance. Th e project utilizes a peak fl ow of
18 cubic feet per second (cfs) and displaced 85% of the
community’s electrical needs in the fi rst year.
Allocation of Funding
Th e Renewable Energy Fund contributed $996,000 and
local funds contributed $2,013,299. REF money went
toward design and construction, and local funds went
toward design, construction, and overhead costs like
maintenance and interest. Other sources of funding in-
cluded the Denali Commission, USDOE Rural Utility
Services, Aleutian/Pribilof Islands Community Devel-
opment Association, and several other institutions.
Learning Experiences/Challenges
1. A few challenges the project encountered included
extreme weather conditions, logistics, and competition
for use of available equipment. Construction began in
2004, but due to a lack of funding early on, the proj-
ect was put to a halt and was restarted again in 2008
when the city acquired additional funding. During
construction, delays in getting personnel and materi-
als made construction time exceed what was planned
as well. Ash overburden and the wet environment in
Atka required erosion protection in most work areas
that disturbed the vegetative mat. Disturbed areas were
later re-seeded with native grass species.
Community Benefi ts
1. Th is project was feasible for the City of Atka largely
because they were fi nally able to cut electricity costs
by displacing expensive diesel fuel. Atkans currently
pay about $7.50 per gallon for heating fuel, and each
household uses about 100 gallons per month. Th is
equals out to $750/month, and they have to pay for
electricity on top of that. Electricity from the commu-
nity’s diesel generators costs 76 cents a kilowatt hour,
compared to 27 cents a kilowatt hour for hydroelectric
power. For a facility like the school, which uses up to
4,000 kilowatt hours a month, that’s more than $1,000
a month in savings. Th ese school savings go to en-
hance school programs and classrooms so students can
continue to learn in a thriving environment.
2. Th e plant started supplying power to Atka’s 59
residents on December 23, 2012. In the summertime,
it also generates some of the power for Atka Pride
Seafoods, a seasonal fi sh processing plant. Saving mon-
ey for community members and local industries has
grown the local economy and encouraged people to
continue residing in Atka.
Project Contact Information
Owner:
City of Atka,
P.O Box 47070, Atka AK 99547
Engineers: PolarConsult Alaska, 907-258-2420
Marsh Creek LLC, 907-258-0050
City contact:
Julie Dirks, City Administrator
Email: dirksjuliea@gmail.com
Case Study Author:
Zoe Tressel, Alaska Energy Authority
Website: Akenergyauthority.org
Phone: 907-771-3000
Chuniixsax Creek Hydroelectric Project
Completed hydroelectric dam, photo courtesy of AEA.
Hydro project construction, photo courtesy of AEA. Published August, 2015