The fuel source is hydrogen, the most abundant element in the universe. Combining with oxygen, the reaction pumps out electricity, heat and pure water. Most fuel cells use fossil fuels, breaking hydrogen from carbon. So fuel cells release some climate-altering greenhouse gases, but less than if the fuel is burned. A company called Energy Conversion Devices is working on an even safer solid-form hydrogen.
Several companies plan to market home systems around the size of a major appliance.
Today, a couple of hundred 200-kilowatt fuel cells are part of the power supply at institutional sites ranging from a New York City police station to Vandenberg Air Force Base. Tomorrow they will be everywhere. Mass-production economies are expected to dramatically drop prices in a few years. GE plans to market business-scale systems by 2002. Recently considered too expensive and heavy for vehicles, fuel-cell technology has been making unanticipated breakthroughs.