One of Energy Concepts’ patented high-efficiency absorption cycles is the "Vapor Exchange" cycle. This cycle proved ideal to solve the problem of how to transport a large, highly seasonal fish catch in a remote village in Alaska during the warm summer months when commercial salmon season is open.

Waste Heat Fired Icemaker by Energy Concepts Co. in Kotzebue, Alaska

The electric power required to run traditional mechanical vapor compression refrigeration cycles to produce ice for storage overwhelms the villages power capacity, which is supplied by two diesel engines. The VX cycle is powered by low temperature waste heat, which is provided by the jacket cooling water from the diesel engines. Although the absorption cycle has higher first cost than traditional ice making equipment, when the cost of the necessary additional electric generating capacity is included, the capital costs are about equal. Since the absorption system requires no additional fuel input, in most scenarios, 70% savings in operating costs can be realized.

The Waste Heat Fired Icemaker has successfully operated during each commercial salmon fishing season in Kotzebue, Alaska since 1993. Diesel engine jacket cooling water at 75°C is used as the heat source to produce 10 tons per day of flake ice for fish storage and transportation. This project was made possible with support from the Alaska Energy Authority (now the Division of Energy of the Department of Community and Regional Affairs), and the Kotzebue Electric Association.