Fuel cells have been around for decades. Now, the Electric Power Research Institute (EPRI) in Palo Alto, California, USA, has developed new fuel cells of the size of a gas furnace, which look like a main-frame computer. According to the EPRI, the cells will supply electricity to homes for !ess than the present cost. The EPRI has joined hands with Analytic Power in Boston, USA, to build an affordable three-kilowatt residential model, which is now undergoing field tests. Fuel cells convert chemical energy in a fuel into electrical energy. First, They extract hydrogen from a hydrocarbon, such as natural gas or propane. Then they strip the hydrogen atoms of their electrons to create electrical current. The by-products in this process are water and heat. The cell is expected to cost about US $3,000. The operating costs should be about 8 cents per kilowatt-hour (Popular Science, Vol 258, No 1).