Target has installed solar panels on the roofs of four of its California stores and plans to install similar systems at 14 more locations later this year, American Business Daily reports. The solar-panel systems will generate about 20 percent of those stores’ annual energy requirements.

A Target store in Stockton, Calif. recently installed solar panels in five grids, spanning roughly 50,000 square feet. A system that size would cost an estimated $3 million to $5 million, said Barry Cinnamon, CEO of Los Gatos, Calif.-based Akeena Solar. “It’s cheaper over the long term to put a solar-power system on your roof and generate your own electricity than it is to rent it forever from a utility.”

Target’s largest competitor, Wal-Mart sent out a request for proposals for solar-power generation late last year.