Ten Eco-Friendly Companies

Imagine, for a moment, a future where electricity is generated not in big power plants but behind your home or in the basement of your office building. High-efficiency, low-polluting fuel cells the size of minivans provide all your power needs. They take hydrogen-rich natural gas or propane and then chemically strip the fuel of its electrons to produce electricity. One byproduct is hydrogen, which can then be funneled into your new, clean-running hydrogen car. While the fuel cells run hotter than anything else in your home, perhaps as high as 1,000 degrees Celsius, that's OK, too--the extra heat is captured and warms the water tank.

Ion America is a quiet Silicon Valley firm pursuing this coveted power paradigm, using solid oxide fuel cells. The three-year old start-up, based at NASA's Ames Research Center in Mountain View, Calif., is still developing its technology.

But the company's first fuel cells are now being tested and the prospects are exciting some energy experts. The U.S. Navy gave Ion America a $2.7 million contract to test its fuel cells in submarines, where another byproduct, oxygen, can be used as breathable air. A Chattanooga, Tenn., university will install a five-kilowatt prototype early next year, and the city is asking for a more powerful, 100- to 200-kilowatt version to use downtown by 2008.

Ion's founder, Indian-born KR Sridhar, started his fuel-cell crusade while heading the Space Technologies Lab at the University of Arizona in the 1990s. He worked for NASA on ways to make breathable air from the carbon dioxide in the Mars atmosphere. When NASA terminated the lab's contract in a late '90s purge, Sridhar looked at the technology from a different angle, wondering if he could make electricity from hydrogen efficiently, which drew him to fuel-cell research.

Sridhar has said he hopes to begin selling products next year. That will help answer questions raised by skeptics. The fuel cells run at such high temperatures, for example, that reliability and stability could pose problems. But if Ion can answer them, old power sources will look like the dinosaurs whose remains they consume.

--Brad Stone