Ten Eco-Friendly Companies

Todd Carter has a plan to alleviate the world's environmental woes. He just needs several hundred million dollars, a lot of corn and 1 billion pounds of cow manure. Carter, president of Panda Development, expects the laughs. --"After I get past the chuckles, I have to tell people, 'No, we're really serious about this'," he says. Panda, a subsidiary of Dallas-based Panda Energy International, is about to break ground on a $120 million plant that could lead to greater use of ethanol (the cleaner but less efficient gas now used sparingly in U.S. automobiles, in part because it takes too much energy to produce).

Panda thinks it's found a solution. The company plans to collect truckloads of cow manure from feedlots. Gasses produced by burning the bovine "biomass" will fuel Panda's plants, which in turn will convert corn to ethanol. Each plant will churn out 100 million gallons of ethanol a year, Carter says.

To be sure, it's unlikely that every car will eventually run on ethanol. But many are equipped to use fuel with at least some ethanol (mileage is slightly worse, but the fuel costs about 20 cents to 30 cents less per gallon than regular unleaded gas). Feedlots love it, too. Bob Josserand, mayor of Hereford, Texas, and owner of one of the country's biggest feedlots, calls Panda's plans "the sexiest project I know of."

--Jennifer Ordonez

5 A Sterling Solution

STM Power: A modern twist on the Stirling engine, including a "Fumes to Fuel'' idea for Ford