Safeway, Kohl's and Wal-Mart are just some of the stores installing solar panels this year, The New York Times reported Monday.

Collectively, the effort could make an impact on the nation's dependence on coal-generated electricity. Wal-Mart, with 17 stores outfitted, could add about 23 square miles of solar paneling to the nation's power structure, the Times reported.

States with incentives -- California, New Jersey and Connecticut -- have the highest concentration of participants. However, in spite of costs -- solar electricity costing 27 cents per kilowatt hour, compared with 6 cents for coal -- Kohl's has outfitted 85 stores with panels and is aiming to include 43 more, the Times said. Macy's has 18 solar-panel outfitted roofs and expects to add 40 more by year's end.

"Green energy is now front and center in the minds of the business sector," Daniel Kammen, an energy expert at the University of California, Berkeley, told the Times. "Very soon retailers will have stickers in their windows saying, 'This is a green energy store.'"