Food retailer Safeway Inc. (SWY) took advantage of the Earth Day 2008 celebration to unveil two new environmentally-friendly stores in Northern California. The company estimates the rooftop solar installations will provide around 20% of each location's energy needs.

Safeway is targeting 23 of its 1,743 stores for outfitting with similar setups. The project will remove an estimated 12.6 million pounds of carbon dioxide from the air each year, the equivalent of taking 1,045 cars off the road.

Solar technology players like First Solar (FSLR) and SunPower (SPWR) should welcome the trend of companies making better use of their rooftops. Last year Google (GOOG) completed the biggest solar installation on a U.S. corporate campus to supply up to one-third the power for its headquarters in Mountain View, CA.

Since solar power is yet to reach cost parity with its coal counterpart, much of the economic benefit of such installations comes in the form of tax breaks. But big subsidy states like California and New Jersey may be forced to cut back on handouts, as falling home prices and a slumping economy cut into tax receipts.

Solar power may be one of the keys to controlling global climate change, but the future is far from bright.

For more on renewable energy check out Hoofy and Boo's always astute analysis: