In 2008, businesses in the Green-e Marketplace program voluntarily purchased more than 2.8 million megawatt-hours of Green-e Energy Certified renewable energy, which is a record, according to the Center for Resource Solutions.
Intel made the largest purchase of renewable energy in history, with a 1.3 million megawatt-hour purchase in January. PepsiCo and Mohawk Paper followed behind.
Green-e Energy certified 69 percent of the overall voluntary renewable energy market in 2007.
Wind and solar industries currently make up about 7 percent of the total renewable energy market, but they are expected to contribute more than 25 percent to renewable energy by 2030, according to Credit Suisse research forecasts.
See companies making the Environmental Protection Agency's Green Power Partnership list here.