10 fixes for the planet - page 2

5. Plastic solar cells: Lightweight and inexpensive, they could be very practical.

Alan Heeger, professor of physics at the University of California, Santa Barbara, loves the traditional solar panels on his roof. "Every day, when the sun comes up, my electricity meter runs backwards, as I sell electricity to the grid," he says. But a system as large as his can cost upwards of $60,000. That's why Heeger is developing so-called plastic solar cells—inexpensive photovoltaic nanochips, 500 times thinner than a human hair. Unlike standard silicon chips, which are synthesized at high temperatures, these cells can self-assemble at room temperature on a flexible plastic film. The film can be bonded to almost any surface, forming a thin coating of solar cells that can be tapped for energy.

Heeger won the 2000 Nobel Prize in Chemistry for developing such materials. He went on to co-found a company called Konarka Technologies, which will bring the first small-scale applications to market later this year. Think of handbags coated with flexible solar cells ("as you walk around, it could charge your cell phone") or tents painted with solar cells, for electricity while camping. "The fact that you can fold it or roll it up shows the cells are very lightweight," says Heeger.

But there's a catch. His chips at present convert only about 5 percent of sunlight (versus 15 to 18 percent for standard solar panels)—and only from the visible part of the spectrum. Ted Sargent at the University of Toronto is developing chips that can harvest an additional 4 percent from the infrared portion. With a combination of plastic cells like these, you could start to get close to useful strengths of 10 to 15 percent. When that happens, the impact could be widespread. "There are a billion or more people with no electricity," Heeger says. "A small system, producing less than 100 watts of electricity, would change their lives, giving them light to read and study or power for a radio and a small TV." And there would be no harmful emissions or moving parts to break down.

6. Climate counts: You can vote with your dollars to support green companies.

Gary Hirshberg is constantly looking for ways to make his organic-yogurt company, Stonyfield Farm, even cleaner. He uses no toxic chemicals, has the largest solar array in New Hampshire and converts yogurt waste into a bio-gas that can be burned rather than turning it into sludge. Now Hirshberg is encouraging others to follow his lead.

Last year he launched a nonprofit and Web site called ClimateCounts.org to rank major corporations, from PepsiCo to Microsoft, on the basis of 22 criteria, including measuring their carbon footprint, reducing emissions and supporting progressive climate legislation. The scores, updated annually, are revealing. Stonyfield Farm itself rated only 63 out of a possible 100 points—and it was one of the top scorers. Apple Inc., despite its hip image, pulled a grade of just 2. "We all have a long way to go," says Hirshberg. But he hopes that consumers will put their dollars behind companies that are trying hard to help the environment. "We have to stop treating the Earth as if it were a wholly-owned subsidiary of our economy," he says.

7. The Aptera: A funky new hybrid-electric car gets 300 miles per gallon of gas.

The dirty secret of automakers, says Jib Ellison, CEO of BluSkye Sustainability Consulting, is that most of the energy used by a car comes from moving the vehicle itself, not the people in it. "That's because cars aren't designed to be as aerodynamic as they could be, and because we have this obsession with heavy vehicles, even though there are now lighter materials that are just as safe," he says. But a prototype car from upstart Aptera Motors in Carlsbad, Calif., could help change all that.