Short-term wind power investments are on the decline, but that hasn't stopped Wal-Mart from announcing a plan to buy wind power from Duke Energy Corp. The purchase will power up to 15 percent of the company's 360 Texas facilities.

This is a first for Wal-Mart, as the company has never before made a direct purchase of wind-generated power.

The 150 MW Notrees Wind Power Project will power up in December and be fully operational by next year. It will provide Wal-Mart with 226 million KWh of power annually, and will offset 139,000 metric tons of carbon — the equivalent of what 25,000 cars would emit.

Wal-Mart plans on producing even more wind power projects in the future, with a 99 MW project scheduled to be up and running by the end of 2009. More projects will be announced soon.

According to the company, its recent announcement will make it 15th on the Environmental Protection Agency's list of companies using green power. Other major organizations on the list include the US Air Force and Whole Foods.