Wal-Mart Stores, Kohl’s, Safeway and Whole Foods Market have started to put on solar panels on their roof to generate electricity for the store. They need to complete the installation before December 31 before the deadline to take tax advantages for these projects. This solar system will provide them 10 to 40 percent of the power a store needs, depending on the weather. 40 percent saving is quite a lot but I wondered how much those solar panels cost.

[via New Launches]