Auxiliary Power Systems for Transportation Applications

Idling of the propulsion engine (or main engine) while a vehicle is at rest is often used to supply power to a variety of auxiliary (i.e. non-propulsion) loads, such as lighting, communications, appliances, cab heating/cooling, pumps, fans, and engine and fuel heating. However, idling of the main engine is accompanied by significant engine inefficiency, which results in higher fuel consumption and exhaust emissions. The goal of this study was to assess the technical and economic feasibility of using fuel cells as auxiliary power units (APUs) for on-road transportation applications.The specific objectives were as follows: - Define the APU requirements for specific vehicle classes based on the APU's end-use; - Determine the most promising fuel cell types for APU systems that match the required performance specifications; - Determine likely system layouts and vehicle integration issues for the most promising fuel cell APU systems; - Compare cost and performance of the most promising fuel cell APU systems with alternative APU approaches; and - Determine the research and development (R&D) technology/performance gaps that must be addressed prior to commercialization.