With rolling brown-outs in California, sticker shock at gas stations nationwide and home heating costs soaring in the northeast, there's a new urgency to the decades-long search for a cheap, small, efficient fossil-fuel alternative. Recent refinements to long-understood technology, called fuel cells, might mean that search is over.
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Fueling the Future

First developed by Sir William Grove in the 1830's, fuel cells can use renewable resources to power everything from a laptop, to an automobile to an entire city, emitting only water and heat as waste products. In the 1960's, fuel cells earned national attention when NASA used them to power the Gemini and Apollo missions and, later, the Space Shuttle. More than 30 years and a billion research dollars later, some companies are ready to put fuel cells to work here on Earth. Their efficiency and flexibility make them a technologically and economically viable solution to air pollution, global warming and our ever-dwindling supply of fossil fuels.

Though they are poised to solve some of the 21st century's most complex energy problems, fuel cells operate on relatively simple processes. Like an average drug store battery, a fuel cell uses a chemical reaction to generate electricity. Unlike the battery, however, fuel cells never die or need re-charging, as long as they are supplied with a source of fuel.

A fuel cell consists of a medium called an electrolyte that is sandwiched between two oppositely charged electrodes. On one side of the fuel cell, hydrogen enters the cell, where a catalyst splits it into its component parts- electrons and protons. Both kinds of particles are drawn towards the other side of the cell, but the protons and electrons take different paths. The protons pass through the electrolyte, while the electrons must take the long way around. This stream of traveling electrons generates electricity, which can be harnessed and put to use. When the electrons and the protons reunite in the presence of oxygen, they spontaneously form usable water and heat.
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Diagram: American Methanol Institute