Wal-Mart boosts rooftop solar

Wal-Mart plans to double the amount of solar power generated from rooftop panels on its California stores.

 Solar panels already installed on 18 Wal-Mart stores produce about 16,000 megawatt-hours of electricity a year, enough to serve about 1,300 homes. The new project will double that amount, with panels installed at 10 to 20 additional sites, the Bentonville, Ark., company said. The rooftop panels are expected to provide 20%-30% of the power needs of the stores where they're installed, at a price either at or below the price of traditional energy. Other retailers, including Target, Macy's and Whole Foods have announced similar solar projects over the last two years.