(Business 2.0) – To most people, they're pond scum. But for Isaac Berzin, algae could address two major environmental issues: pollution and power production. As founder of GreenFuel Technologies in Cambridge, Mass., Berzin has designed a system that reduces power-plant emissions by redirecting smokestack exhaust into algae-filled bioreactors. The algae feast on the greenhouse gases, consuming 30 to 80 percent of the plants' pollutants, depending on the stage of photosynthesis. After ingesting the fumes, the algae can be processed into a biodiesel that fuels the plant. "It's so simple, you want to cry," Berzin says.

The business model is a bit trickier. Right now GreenFuel's system is best suited to natural-gas facilities, which account for less than 18 percent of the nation's electricity production. "The big value won't come until they use it for coal plants," says Melanie McCoy, director of environmental projects at Detroit Edison. But Berzin isn't worried. GreenFuel's first customer, a natural-gas plant in the Southwest, will have a large-scale test running by next summer. Meanwhile, the company has identified 1,000 U.S. facilities that fit its criteria, and with just a fraction as customers, annual revenue could surpass $100 million. Not bad for pond scum.