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HomeMy WebLinkAboutPoint Lay Heat Recovery Case Study - REF Grant 2195467 est 2015Point Lay, Alaska Point Lay Heat Recovery Project Quick Facts Total Project Costs: $435,503 Capital Costs Design: $39,591 Construction: $395,912 Equipment Generator Make/Model: Caterpillar 3508 (Marine) Output: 682 BKW, or 915 BHP Diesel Fuel Off set Estimated Annual: 6,000 gallons Actual Annual: 20,000 gallons 2013-2014: 20,000 gallons Fuel Savings Estimated Annual: $46,000 Actual Annual: $98,000 2013-2014: $98,000 Estimated Payback: 8.8 years Actual Payback: 4.4 years CASE STUDY Project Overview In partnership with the Alaska Energy Authority, the North Slope Borough designed and constructed a heat recovery project in the city of Point Lay, Alaska. Th e system connects the North Slope Borough Health Clinic, Search & Rescue Offi ce, and Police Depart- ment to their diesel-generated power plant. Th ese buildings utilize recovered heat from the plant that would otherwise be emitted into the atmosphere via radiators. Objectives Th e project objectives were to deliver recovered heat from the diesel plant to several buildings in Point Lay and to reduce heating costs to the power house. Heat Recovery-How it Works As a rule of thumb, engines are 30% effi cient. Th at is, of the fuel energy input, 30% each goes to horsepower, jacket water heat, and exhaust heat. 10% goes to radi- ation and other losses. Jacket water cools the engine by dissipating almost 28% of the heat it generates. Th is heat is low grade and is sent to the atmosphere using radiators or cooling towers. Heat recovery is a unique system that takes heat captured in the jacket water and harnesses it for space heating. Th e jacket water loop is isolated from the building heating loop by a heat exchanger so that the heat recovery system does not impact engine performance. Economic Feasibility Th e system became operational in August of 2013. Since then it has provided the community with 2,153 MMBtu of thermal energy and displaced 20,000 gal- lons of diesel fuel. Th is displacement has saved Point Lay $98,000. Over its 20 year projected lifespan, the project has a benefi t/cost ratio of 1.37, meaning that the benefi ts outweigh the costs by 1.37. Photo, left : Diesel engine with attached heat recov- ery system. Photo courtesy of AEA. Allocation of Funding Th e Alaska Energy Authority’s Renewable Energy Fund granted $395,912 for the fi nal design and con- struction of the heat system. Local funds matched $39,591 and contributed to the construction. Relevant Information Th e heat recovery system is designed to reduce the amount of fuel consumed at the end user building and is not intended to serve as a primary heat source. Th e heating system in the end user building must be fully operational, maintained, and set to operate at appro- priate temperatures to allow the heat recovery system to function. Th e amount of heat available for recovery varies with the electrical load on the generators. Learning Experiences/Challenges Th e new Point Lay power plant and heat recovery sys- tem was completely destroyed by fi re as it was nearing the completion of the construction phase. Luckily, the original power plant was still in operation and was not damaged by the fi re. Th e cause of the fi re appeared to be sparks from welding that ignited during the night. Proper safety oversight and burn permits could have prevented this disaster. Th e North Slope Borough and the construction contractor were insured, however, the rebuild of the system delayed the project by 2 years. Community Benefi ts 1. Th e primary community benefi t of this project is the lowered cost of heating the North Slope Borough’s community buildings. Th e saving to the community can be added to the maintenance and equipment re- placement funds to off set future costs. 2. Other varied benefi ts include local construction jobs, a clean energy source, increased heating reliabil- ity, increased system-wide fl exibility, less air pollution in the village from decreased fuel use, lower probabili- ty of fuel spills in the village, and reduced maintenance of heating plants in each building. Project Contact information Parties Involved: Parties Involved: Richard San Jose, Project Manager Email: richard.sanjose@north-slope.org Phone: 907-852-0489 David Hodges, NSB Dept. of Public Works Email: dhodges@gci.net Phone: 907-243-1940 Case Study Author:Case Study Author: Zoe Tressel, AEA Email: ztressel@aidea.org Phone: 907-771-3000 Portion of heat recovery system. Photo courtesy of AEA. Point Lay Powerhouse. Photo courtesy of skweskimos.com Point Lay, Alaska