Retail giant's pilot projects will generate 20 megawatt hours per year of solar power at 22 stores in California and Hawaii.
The company on Monday said it will generate as much as 20 megawatt hours per year of solar at locations in California and Hawaii. Solar panels will be installed at certain Wal-Mart stores, Sam's Clubs and a distribution center.
The winning bidders for the contract are BP Solar, SunEdison and SunPower subsidiary PowerLight.
Wal-Mart intends to test the systems as part of its plan to eventually be supplied entirely by renewable energy, the company said.
Each solar installation will be able to provide up to 30 percent of a store's power needs and will result in a reduction of between 6,500 and 10,000 metric tons of greenhouse gases a year, Wal-Mart said.
"Pilot project stores are expected to achieve savings over their current utility rates immediately--as soon as the first day of operation," David Ozment, Wal-Mart's director of energy, said in a statement.
The Wal-Mart bid, first disclosed in January of this year, has been closely watched by the solar industry.
Because of Wal-Mart's size, its investments in solar power could have a significant financial impact for solar providers. It could also help set a precedent for large-scale investments in renewable energy.
Wal-Mart's contracts with the solar providers were originally expected to be awarded in February but were pushed back until now.