Within the next five years, sewage and other types of wet waste could produce enough energy to power cars, homes, and factories. A team headed by Ashok Bhattacharya, director of the process technology group at England's Warwick University, has developed a method of pulling hydrogen gas from sludge and other wet biomass-hydrogen that can be used in fuel cells. "The 'wet' is the innovation," he says. Dried wood pulp and other biodegradable stuff has been used to produce hydrogen for years. But according to Bhattacharya, wet biomass yields about twice as much of the gas.