Project Lead: Chuen-Sen Lin

Improving efficiency of diesel engines in rural Alaska villages is an inexpensive, short-term opportunity to reduce fuel costs for those communities.   Most diesel generators operate at an efficiency of 30-40%, with the rest of energy being lost through the both the engine exhaust and the water jacket.  One way to increase efficiency is by using this waste heat for space heating applications.   However, sometimes the power generation facility for a particular community is located too far from other buildings to effectively heat buildings with this waste heat.   Also, the need for space heating in the summer months is limited.  

For this reason, the Alaska Center for Energy and Power (ACEP) has been investigating a number of technologies which could be used to generate additional power from the waste heat stream. An example is the 400kW geothermal power plant at Chena Hot Springs Resort.   The power plant, built by United Technologies Corporation, was originally designed to operate off waste industrial heat applications, including large diesel recip engines.   Unfortunately, the units installed at Chena would require more waste heat than is available in most villages – 2 MW and above.  

ACEP has been conducting an assessment of the availability of smaller power generation units which would be more applicable in rural Alaska.   In 2009, ACEP will begin testing and evaluating several waste heat recovery devices, both at its diesel engine test bed in Fairbanks, and in a field installation in Kotzebue.

In addition to assessing technical issues, data on the costs associated with installing, operating and maintaining these systems is being collected.   Additional field trials are planned in 2010.   This project is funded by the Department of Environmental Conservation (DEC), the Environmental Protection Agency (EPA), and the Alaska Energy Authority (AEA).

In addition to this research project, ACEP is testing other ways of improving diesel engine efficiency, including varying fuels and fuel mixtures as well as evaluating designs for stack heat recovery.