HomeMy WebLinkAboutGulkana Central Wood Heating Project Case Study 02-01-2016-WOODGulkana, Alaska
Biomass boilers provide long-term and sustainable heat supply
Quick Facts
Total Project Costs: $553,356
Funding: Renewable Energy Grant Fund: $414,686
Matching Funds: $102,000
Capital Costs
Design: $46,000
Construction: $507,356
Equipment
Make/Model: (2) Garn WHS 2000
Output: 700,000 Btu/hr
(1) Tarm 4.0 - Output: 147,000 Btu/hr
Diesel Fuel Offset
Estimated annual: 14,643 gallons
Actual avg. annual: 10,769 gallons
Comprehensive savings: 35,000 gallons
(Oct. 2010-Dec. 2014)
Fuel Savings
Estimated annual: $33,000
Actual annual: $36,000
Comprehensive savings: $117,000
(Oct. 2010-Dec. 2014)
Jobs Created: One full-time equivalent
Gulkana Central Wood Heating Project
Project Overview
Through the Renewable Energy Grant Fund (REF),
Alaska Energy Authority (AEA) funded construction
of a central wood heating system in Gulkana, Alaska.
The community installed two Garn WHS 2000 cord-
wood-fired boilers, a Tarm pellet-fired boiler, and a
distribution system to connect community buildings.
The majority of pellets used to feed the system are
purchased from Anchorage. Cordwood is provided as
a byproduct of hazardous fuels treatments and road
construction activity. To promote safety, oil-fired boil-
ers remain as ready backups.
Objectives
The main objectives of this project were to displace
fuel oil and provide the community of Gulkana with
a renewable, reliable, and cost effective energy source.
These objectives are achieved by heating community
facilities and the community water circulation loop
with the biomass system described above.
Product Selection
A cordwood-fired hydronic system was chosen be-
cause of its long life, low maintenance, ease of con-
struction, and simple operation. The Tarm pellet-fired
boiler was chosen to compliment the cordwood fired
boilers during the night and weekends because it
requires less maintenance and labor.
Economic Feasibility
The project became operational in October 2010.
Between October 2010 and December 2014, the
boilers produced 3,800 MMBtu of thermal energy and
displaced 35,000 gallons of diesel fuel. This displace-
ment has resulted in $117,000 in fuel savings for the
community. With proper maintenance, the boiler life
is expected to exceed 20 years.
Allocation of Funding Boiler facility & wood storage,
all photos courtesy of Dan Bihn.
Allocation of Funding
AEA’s Renewable Energy Grant Fund contributed
$414,686 to the project. Funds went to boiler purchase,
construction/installation of a combined heat building
and wood storage, and adapting buildings to hot water
heat systems. $10,000 was provided through the US
Forest Service “Jumpstarting Wood Energy in Alaska”
grant, and local match provided the remaining funds.
Fuel and Storage
The system is designed to displace 90 percent of
the fuel oil previously used in community facilities.
Cordwood is supplied locally, and quartlery trips to
Anchorage are made to purchase pellets and other
supplies. The fuel hopper for the pellet system has to
be filled once every several days whereas the cordwood
system must be fed several times each day. The com-
munity is currently investing in a local pellet mill to
reduce costs, and it is expected to become operational
in 2016.
Learning Experiences/Challenges
The project originally included two Tarm boilers in ad-
dition to the two Garn WHS 2000s. Due to a shortage
of funding the project was reduced to two Garn and
one Tarm unit. Gulkana was also unable to purchase a
silo storage container for their bulk pellets. In spite of
funding challenges, the project has thrived and savings
continue to benefit the community.
Another lesson learned was that the Tarm boiler did
not have an UL rating and had to be modified to an
atmospheric system for Fire Marshall approval. Future
equipment evaluations will include making sure that
the systems are certified in Alaska.
Community Benefits
The biomass heated hot water circulation loop is inte-
grated with the conventional hot water heating sys-
tems in community buildings using a heat exchanger.
In June of 2013, additional funding was provided by
AEA to modify the hydronics system for better heat
distribution. A Btu meter measures the amount of heat
delivered to customers, allowing the tribe to meaure
and sell the energy.
The two Garn WHS 3200s and Tarm boiler currently
supply heat to four duplexes, a teen center, community
hall administration, fitness center, shop, new offices,
clinic, the potable water distribution loop, and a new
bus garage. Thanks to this project Gulkana community
facilities have a long-term and sustainable heat supply.
Project Contact Information
Parties Involved:
Jim Vail, AEA
Email: jvail@aidea.org
Phone: 907-771-3064
Sandra Tsinnie, Gulkana Council
Email: stsinnie@gulkanacouncil.org
Phone: 907-822-3746
Case Study Author:
Zoe Tressel, AEA Intern
Website: Akenergyauthority.org Garn boilers
Heat exchanger piping
Gulkana Central Wood Heating Project
Updated February, 2016