A new Wisconsin venture called GreenWhey Energy will turn the slurry from five cheesemakers and a soyfood ingredient plant into energy and clean water. An anaerobic digester will process 500,000 gallons a day of milky whey - the wastewater that results from the cheesemaking process. When the whey goes through the digester, microorganisms break it down and digest it, leaving methane gas (biogas), carbon dioxide, clean water, and a nutrient-rich solid that can be used as fertilizer. The biogas squeezed out of the whey will generate 3.2 megawatts of electricity, piles of nutrient-rich fertilizer, heat for two area cheese factories, and water that is clean enough to drink, says GreenWhey. The power, enough to supply about 3,000 homes, will be sold to the utility, Xcel Energy, in nearby Eau Claire.