The overall trend is connected to a US Environmental Protection Agency (EPA) program called the Green Power Partnership, which began in 2001 with 21 founding partners and the intention of increasing the use of renewables among US organizations -- while ultimately leading to the development of new sources of green power.
"We work with companies to help them buy green power," says EPA's James Critchfield. "Some are mom-and-pop sized companies and some are listed in the Fortune 500. The size of the purchase isn't as important as the commitment each company is making. We look at the percentage of their energy load."
Last year Whole Foods of Austin, Texas, an upmarket chain of natural and organic foods supermarkets, became the first Fortune 500 company to offset 100% of its electricity use with wind credits. It buys 485,000 MWh of wind energy credits from Renewable Choice Energy, another Colorado company.
"The partnership provides companies with recognition," says Critchfield. But one of the other things they receive from us is technical assistance -- from navigating the purchase process to providing tools to measuring their consumption to finding sources in their region to buy their credits from."
Other major companies, such as Starbucks, Fedex Kinko's, Nike and Johnson & Johnson have also bought large amounts of renewable energy in the form of credits as part of the EPA program. The top-ranked purchaser, the US Air Force, buys 1,066,397 MWh, 11% of its consumption and more than twice as much as second-ranked Whole Foods. The program now has more than 600 partners, including several other Fortune 500 companies, state and federal agencies, trade associations and universities.
"A number of different sectors seem to be suited for green power," Critchfield says. "Institutions like universities, for instance, realise that being more environmentally responsible can actually be a differentiating factor in the quest for higher enrolments."
Combined annual purchases in the program now amount to 3.3 million megawatt hours. A renewable energy certificate represents the benefit, in reduced carbon emissions, of a unit of electricity generation, typically one megawatt hour.
"The program is about market transformation in the sense that we're hoping increased purchasing of renewables will lead to more renewables," says Critchfield. "So by buying into the program, companies are spurring development. We hope that sometime in the future green power will be so prevalent that a program like this won't be needed. It's hard to say what the future has in store, but the market will let us know when it doesn't need us anymore."