02-10-2010, 09:33 AM
INTRODUCTION
Fuel cell may be defined as “an electro chemical device for the continuous conversion of the free energy change in a chemical reaction to electrical energy”.
Fuel cell systems offers clean and efficient energy production and are currently under intensive development by several manufacturers for both stationary and mobile applications. Fuel cells found its first application during the NASA Apollo moon landing program in the late 1960s. It was a logical choice as an energy source. It had no moving parts, was compact in size, and was founded with an unlimited budget. Powered simply by hydrogen gas, the fuel cell produced dc power, pure water as its exhaust, and heat. The dc supply charged the spacecraft batteries. The water was used by the crew and the heat generated by the fuel cell was rejected to the void of space. At that time a brief study was conducted as to how fuel cells could be used to power homes in the same manner as spacecrafts. The study was very short lived but the dream of powering automobiles and houses using fuel cells was born in earnest.
Fuel cells, until recently a curiosity largely confined to the space program, are emerging as a valuable clean and efficient generator of electricity. A number of companies are developing fuel cells for use in stationary applications. Most of the current applications for fuel cells utilize natural gas as a fuel. In certain states, such as New York and Connecticut, fuel cells operating on natural are recognized by the states as a renewable energy source. Recently, however, fuel cells, mostly phosphoric acid, have been shown to operate well on renewable biogas fuels, such as anaerobic digester gas (ADG) produced at wastewater treatment plants as well as landfill gas (LFG) and gas produced at beer breweries.