Introduction

The supply of reliable, cost-effective electric power with minimal environmental impact is a constant concern of Department of Defense (DOD) installation energy personnel. Electricity purchased from the local utility is expensive and represents only about 30% of the original energy input at the generating station due to generation and distribution inefficiencies. Because of master metering and large air conditioning loads, the demand portion of the installation's electric bill can be in excess of 50% of the total bill.

While the electric utilities in the United States have a very good record of reliability, there is significant potential for improving the security of electrical power supplied by using on-site power generation. On-site, dispersed power generation can reduce power outages due to weather, terrorist activities, or lack of utility generating capacity. In addition, as increased emphasis is placed on global warming, acid rain, and air pollution in general, the development of clean, highly efficient power producing technologies is not only desirable, but mandatory. Since the majority of central heat plants on U. S. military installations arc nearing the end of their useful life, there is an opportunity to replace outdated existing equipment with modem technologies.

the technology

Fuel cells are electrochemical power generators with the potential for attaining very high electrical energy conversion efficiencies while operating quietly with minimal polluting emissions. In addition, by-product thermal energy generated in the fuel cell is available for use for cogeneration of hot water or steam, bringing the overall potential conversion efficiency (electrical plus thermal) to approximately 85%. Air emissions from fuel cells are so low that several Air Quality Management Dislricts in the United States, including several in California which has the nation's strictest limits on air pollutants, have exempted them from requiring a permit to operate.

Phosphoric Acid Fuel Cells (PAFCs) are in the initial stages of commercialization. While PAFCs are not economically competitive with other more conventional energy production technologies at the present time, current cost projections predict that PAFC systems will become economically competitive within the next few years as market demand increases.

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