Power Spray

Spray-on solar cells will shake up the electricity market by 2015. University and private labs in the U.S., Australia, Switzerland and Canada are developing cost-effective plastic coatings containing microscopic particles of copper, indium, gallium and titanium. Painted on building rooftops and exteriors, they’ll absorb sunlight and produce electricity just as bulky solar panels do now.

One big plus: The cell coatings could generate power even on cloudy days, making this solar catcher up to three times more efficient than today’s solar modules. That’ll give them the potential to cut a company’s electricity purchases by 50% to 75% and even offer some companies the chance to sell power to utilities when their own needs ebb.