HomeMy WebLinkAboutCity and Borough of Wrangell - Wrangell Hydroelectric Boilers - Sept 2016 - REF Grant 2195423Wrangell, Alaska
Hydroelectric boilers decrease energy cost by 48 percent
Quick Facts
Total Project Costs: $1.9 million
Funding:
Renewable Energy Fund: $1,862,387
Local Funds: $76,358
Capital Costs:
Design: $288,175
Construction: $1,650,570
Equipment
Boiler Make: (3) Precision Boilers
Output: 160 kW (Nolan Center), 240 kW
(Public Safety), & 700 kW (Schools )
Diesel Fuel Offset
Estimated Annual: 100,000 gallons
Actual Annual: 84,000 gallons
Feb. 2011-Dec. 2014: 305,000 gallons
Actual Fuel Savings
Estimated Annual: $163,112
Actual Annual: $145,000
Feb. 2011-Dec. 2014: $640,000
Benefit/Cost Ratio: 1.91
Estimated Simple Payback: 11.9 years
Wrangell Hydroelectric Boilers
Wrangell, AK., photo courtesy of Sitnews.us
Project Overview
In collaboration with the Alaska Energy Authority
(AEA), Wrangell Municipal Light & Power (WMLP)
completed the design, construction, and integration
of three electric boilers in Wrangell, Alaska. The new
electric boilers convert excess energy from the Tyee
Lake Hydroelectric facility into usable heat energy.
The three building complexes that directly benefit
from this energy are the Nolan Center, Public Safety
Building (home to the fire hall, court, and public safe-
ty hall), and the High/Middle Schools.
Objectives
The main objective of this project was to reduce the
community’s reliance on diesel fuel to heat facilities
reducing the cost of heat energy while lowering the
city’s carbon footprint.
Reasons This Project Was Chosen
Wrangell was using 2,982,822 gallons of diesel fuel an-
nually to heat their entire community. The new elec-
tric boilers’ capacity and efficiency provide a cleaner
source of fuel and save thousands of dollars annually.
Using an electric boiler also reduces maintenance
costs when compared to diesel boilers.
Economic Feasibility
The system became operational in February of 2011.
Between February of 2011 and December of 2014,
it produced 30,090 MMBtu of thermal energy and
displaced 305,000 gallons of diesel fuel. This displace-
ment saved the community $640,000 in energy costs.
Over its 20 year projected lifespan, the project has a
calculated benefit/cost ratio of 1.91.
Any overages in energy output at the Tyee facility
are given to WMLP by SEAPA in the form of a re-
bate equal to the overage amount. This has allowed
Wrangell to keep their electrical rates at eight cents per
kWh. This helps residents with heating costs and en-
courages them to use electric boilers instead of diesel.
This rate has been unchanged until recently. Due to
projects that SEAPA is performing with Tyee’s excess
water, there is not as much overage as Wrangell nor-
mally anticipates. As a result, rebates were lowered and
electricity rates were increased slightly to 8.5 cents.
Though this isn’t a huge bump, WMLP hopes to bring
the cost back down for residents soon.
Community Benefits
By implementing the conversion to electric boilers, the
surplus energy produced by Tyee is used and the cost
of energy for City facilities has decreased by approxi-
mately 48 percent. These savings have been passed on
to WMLP customers through a decrease in taxes and
power rates, which benefit all Wrangell community
members.
The Tyee Hydroelectric Facility has provided a steady
electric rate to WMLP for 6.8 cents per kWh for the
last 17 years. Using excess energy from this facility
has allowed the utility to reduce their dependence on
diesel fuel, a resource that is constantly fluctuating in
price.
Project Contact information
Parties Involved:
Clay Hammer, WMLP superintendent
Email: powerplant@gci.net
Phone: 907-874-3602
Brooke Williams, WMLP secretary
Email: wmlp@gci.net
Case Study Author:
Zoe Tressel, AEA
Website: Akenergyauthority.org
Phone: 907-771-3000
Hydroelectric boiler, photo courtesy of WMLP.
Power and Storage
Electrical power is provided to Wrangell Municipal
Light & Power (WMLP) by the Tyee Hydroelectric fa-
cilities, owned by the Southeast Alaska Power Agency
(SEAPA). Currently, Tyee has the capability of produc-
ing 20 MW of power. During the summer months, ap-
proximately 11 out of the 20 MW are excess power and
during the winter 6-7 MW are excess. The community
buildings that were converted to electrical energy have
oil fired boilers in place as a back up energy source.
Learning Experiences/Challenges
The original application identified eleven buildings for
conversion to electric boilers. Due to a reduction in
funds it was only feasible to construct heating systems
for the Nolan Center, Public Safety Building, and the
High/Middle Schools. These buildings were ranked
according to highest community need and value.
With the success of the project, private homes and
businesses followed suit. WMLP has found that the
additional electric demand has a negative impact on
their distribution and stand-by generation capabilities.
They partnered with Cold Climate Housing Research
to promote air source heat pumps as alternatives to
resistance-based electric boilers for future communi-
ty conversion. These pumps can produce up to three
times the heat with the same amount of electrical
energy.
Wrangell Hydroelectric Boilers
Published Augsut, 2015