HomeMy WebLinkAboutGulkana_Central_Wood_Heating_Case_Study_Sep_2015_REF_Grant_2195381Gulkana, Alaska
Biomass boilers provide long-term and sustainable heat supply
Quick Facts
Total Project Costs: $553,356
Capital Costs
Design: $46,000
Construction: $507,356
Equipment
Make/Model: (2) Garn WHS 3200, (1) Tarm 4.0
Output, Garn WHS 3200: 700,000 Btu/hr
Output, Tarm 4.0: 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)
Simple Payback: 15.4 years
Jobs Provided: One full-time local
Gulkana Central Wood Heating Project
Project Overview
Through the Alaska Energy Authority (AEA) Re-
newable Energy Fund granted money to construct
a central wood heating system in Gulkana, Alaska.
The community installed two Garn WHS 3200 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 Lowe’s in Anchorage. Cordwood is
provided as a byproduct of local firewood mitigation
and road construction activity. To promote safety, oil-
fired furnaces remain as ready backups.
Objectives
The main objectives of this project were to displace
diesel fuel and provide the community of Gulkana
with a renewable, reliable, and cost effective energy
source. These objectives are achieved by heating com-
munity facilities and water system with the biomass
system described above.
Reasons This Product Was Chosen
A cordwood-fired hydronic system was chosen be-
cause of its long life, low-maintenance, simple con-
struction, and available electric backup. 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 of 2010.
Between October of 2010 and December of 2014, the
boilers produced 3,800 MMBtu of thermal energy and
displaced 35,000 gallons of diesel fuel. This displace-
ment has saved the community of Gulkana $117,000
in fuel sacvings. With proper maintenance, the boiler
life is expected to exceed 20 years.
Allocation of Funding Boiler facility & wood storage, photo courtesy of Dan Bihn.
Allocation of Funding
The Renewable Energy Fund contributed $500,000
to the project. Funds went to boiler purchase, con-
struction/installation of a combined heat building and
wood storage, and adapting buildings to hot water heat
systems. Jumpstart, a non-profit program, donated
$10,000 with other match contributing the remaining
$43,000
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 pellet system requires less labor than
the cordwood system. 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 community is currently investing in a local
pellet mill to reduce costs, but this has yet to be com-
missioned.
Learning Experiences/Challenges
The project originally included two Tarm boilers in
addition to the two Garn WHS 3200s. Due to a lack
of funding tghe project was reduced to two Garn and
one Tarm unit. Gulakna was also unable to purchase
a silo storage container for their bulk pellets. In spite
of funding issues, the project has thrived and savings
continue to benefit the community.
Another lesson learned was that lthough the rating on
Tarm is standard throughout the Lower 48, the Alaska
fire marshall did not accept the rating for Gulkana.
Future equipment evaluations will include making sure
that the systems is certified in Alaska.
Community Benefits
The community water system is heated to prevent
freezing. It is then integrated with conventional hot
water heating systems using a heat exchanger. In June
of 2013, additional funding was provided by AEA to
modify the hydronics system for better heat distribu-
tion. A Btu meter measures the amount of heat deliv-
ered 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, 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, photo courtesy of Dan Bihn.
Heat exchanger piping, photo courtesy of Dan Bihn.
Gulkana Central Wood Heating Project
Published August, 2015