Intel has become the largest customer for 'green' electricity in the US after buying more than 1.3 billion kilowatt hours a year of renewable energy certificates.

The certificates have been bought from the US Environmental Protection Agency, and will fund solar, small hydro-electric and biomass power supplies.

The purchase moved Intel instantly to the top spot on the Fortune 500 Green Power Partners list.

"We have a long history of commitment to the environment, and energy efficiency is an important consideration in everything we do, from building transistors to designing microprocessors and running factories," said Intel president Paul Otellini.

Otellini is also a member of the Copenhagen Climate Council, a group of industry leaders working to achieve an effective global climate treaty at next year's UN Environmental Summit.

"Our renewable purchase is just one part of a multi-faceted approach to protect the environment, and one that we hope spurs additional development and demand for renewable energy," Otellini added.

Intel is buying the certificates in an attempt to offset some of its power use. Renewable power providers in areas where Intel operates will receive funds to build their businesses.

The distribution is handled by renewable energy specialist Sterling Planet.

"Intel's investment provides significant economic stimulus to production-based renewable energy markets that benefit from the additional demand and liquidity that such a large volume purchase creates," said Mel Jones, president of Sterling Planet.

"This purchase benefits the tradable renewable energy markets and adds greatly to the underlying economics of renewable energy project development."