Fuel cells convert chemical energy into electricity. The most common type of fuel cell is an oxygen/hydrogen or oxygen recombinant. The process is accomplished in a similar way to the ordinary battery cell, with two electrodes, only instead of the battery being recharged by reverse electric current and hydrogen being given off by the anode, oxygen by the cathode under discharge, The oxygen and hydrogen are pumped into porous electrodes, thus priming them for discharge, when the oxygen and hydrogen recombine to form water: oxygen recombinant. Fuel cells using hydrogen as a fuel and oxygen from air are an attractive proposition as all stages of the energy process can be environmentally benign. Hydrogen is however exlosive on contact with air though modern storage technologies overcome this problem.

GETTING THE HYDROGEN

Gathering the hydrogen can be done from just water, through electrolysis, using natural gas, or anaerobic respiration of certain plant/algie and then if neccessary storing for later use in a cell. Fuel cells are highly efficient at over 80%, very quiet in use and a potentially pollution free whole process. Alternative technology for many battery powered applications such as zero emission vehicles and portable energy systems. Of note are Chicago public transport trials, with fuel cells powering buses, where the weight/mileage ratio is similar to diesel engines currently in use and acceleration is claimed to be even better with a similar amount of available power and in U.K. the Ballard experimental bus.