HomeMy WebLinkAboutUnalaska Heat Recovery Case Study - REF Grant 2195449 est 2010Unalaska, Alaska
Unalaska Heat Recovery Project
Quick Facts
Total Project Costs: $1,919,807
Funding: Renewable Energy Fund, Local Funds
Capital Costs
Design: $125,000
Construction: $1,794,807
Equipment
Make/Model/Output: (2)Wartsilla 12V32, 5211 kW/unit
Make/ModelOutput: (2) CAT C280-16, 4400 kW/unit
Make/Model/Output: (1) Black Start C9, 250 kW/unit
Make/Model/Output: ORC Green Machine, 65 kW/unit
Diesel Fuel Offset
Estimated Annual: 125,000 gallons
September 2014-June 2015: 15,747 gallons
Fuel Savings
Estimated Annual: $385,000
September 2014-June 2015: $52,280
Estimated Payback: 2.5 years, city investment
Actual Payback: 30.6 years
CASE STUDY
Project Overview
Th e city of Unalaska used grant funds for the purchase
and installation of three Electratherm heat recov-
ery units in the old Dutch Harbor powerhouse. Th e
equipment allows them to utilize excess heat radiat-
ing from three ORC Green Machine generators. Th e
Electratherms use the Organic Rankine Cycle (ORC)
generators to produce up to 150 kW with no addition-
al diesel fuel. Th is waste heat recovery system was also
designed for expansion to include excess heat from
higher power demands when the new powerhouse
became operational in 2010.
Objectives
Th e main objectives of this project were to save Un-
alaska energy costs by displacing expensive diesel fuel
and to reduce waste diesel heat that would otherwise
be emitted as pollution to the atmosphere. In addition
to this, it was the City’s goal to reduce the amount of
fuel purchased from North Pacifi c Fuel Company.
Using a system that is designed to convert waste heat
to electricity was the ideal & natural choice for the
community.
Reasons This Product Was Chosen
By adding 150 kW of clean renewable power per unit,
the power that the City purchases from UniSea and
North Pacifi c Fuel was reduced. Th is has resulted in
a signifi cant cost savings directly passed on to com-
munity members. Aft er the new powerhouse was
constructed, the City bought and installed two Wart-
sila 12V32 engines and Black Start generator sets to
supply heat to both the old and new powerhouses.
Economic Feasibility
Th e three Electratherm heat recovery systems became
operational in September of 2014 and have since gen-
erated 251,959 kilowatt hours of electricity and dis-
Dutch Harbor Powerhouse. Photo courtesy of AEA.
placed 15,747 gallons of diesel fuel. As of June 8, 2015,
the community has saved between 32 and 52 thousand
dollars. Over its projected 20 year lifespan, the project
has a calculated benefi t/cost ratio of 4.62, meaning that
the benfi ts will outweigh the costs by 4.62.
Allocation of Funding
Th e Renewable Energy Fund contributed $1,300,000
and local funds contributed $619,807. Project costs
and expenditures each totaled $1,919,807. Th e Renew-
able Energy Fund money went to the fi nal design and
construction portion of the project. Th e local matches
went to purchasing the three Organic Rankine Cycle
units.
Fuel and Storage
Dutch Harbor Powerhouse currently purchases their
fuel from North Pacifi c Fuel and UniSea. Upon pur-
chase, it is used to run the Organic Rankine Cycle
generators, the Wartsila 12V32 engines, and the Black
Start generator sets.
Learning Experiences/Challenges
1. During the fi nal site selection process, soil testing
determined that there was a small amount of PCB (a
substance that is a probable cause of animal & human
cancer) contamination on the most preferred site. Th e
cleanup project was bid and work began in April 2007.
Unfortunately the extent of the contamination far ex-
ceeded the preliminary estimates and work continued
through April 2008. Despite the setback, cleanup was
sucessful and construction began shortly aft erward.
2. With the help of the Electratherm ORC units, the
company is producing more power than anticipated.
Th e powerhouse hopes to add a fourth unit to their
system, but until their electrical demand increases a
fourth unit would not be very effi cient. Th e company
is currently looking into selling power to several fi sh
processing companies in order to increase their electri-
cal demand and add the fourth unit. Th is would enable
them to utilize more waste heat and would further
reduce their dependency on volatile diesel fuel.
Community Benefi ts
1. Th e new Power house has been in service since
December 17, 2010 and has produced over 4,500,000
kWh of electrical energy with an average effi ciency of
16 kW per gallon of fuel. Th is increase of fuel effi cien-
cy from 14. 5 has drastically reduced the cost of elec-
trical generation through fuel savings and reduced the
community’s carbon foot print.
2. It was estimated that customers would see a $0.02 to
$0.03 per kilowatt hour (kWh) reduction in their rates
aft er completion of this project. Actual reduction rates
have averaged substantially higher at an $8.97/month
decrease in costs for each of their 52,280 customers.
Project Contact Information
Parties Involved:
Jim Fitch, Powerhourse supervisor
Email: jfi tch@ci.unalaska.ak.us
Phone: (907) 581-1831
Dan Winters, Director of Public Utilities
Email: dwinters@ci.unalaska.ak.us
Phone: (907) 581-1260
Case Study Author:
Zoe Tressel, AEA
Email: ztressel@aidea.org
Phone: 907-771-3000
Location map of Unalaska. Photo courtesy of Google Maps
Unalaska, Alaska