Earth Day technology: the spray-on solar panel?
New firms are challenging conventional rooftop solar by using thin-film technology on windows and even indoors. On this Earth Day, conventional Chinese companies are the cost leaders. But US firms have the technical edge.
The solar energy industry is thinking beyond the roof. Instead of those large flat rooftop solar arrays, some companies are trying to convince architects and builders to use windows to generate electricity using nearly transparent plastic film that can be sprayed on or rolled on with an adhesive.
How about inside the building? The same technology can be used to collect juice from ceiling. As the world celebrates Earth Day, the solar industry is trying to capture energy in places never considered before.
“It puts energy harvesting everywhere,” says Ken McCauley, a senior vice president at Konarka, a Lowell, Mass., company that is producing electricity from solar cells printed onto thin plastic film.
There could be widespread implications if this young arm of the solar industry takes off. The technology is under consideration for everything from cellphones to the sunroofs of luxury cars, but any big gains would come if thin-film solar takes off in buildings, which currently consume 40 percent of the nation’s power. That would reduce America’s carbon footprint. If it can bring down costs, America’s solar industry could also get a leg up on Chinese competitors, who currently command nearly half the world’s solar market but apparently have not yet mastered the new technologies.
“There is room for enormous innovation,” says Christiana Honsberg, director of the Arizona State University Solar Power Lab. “We are only limited by the imagination.”
Unlike most conventional solar cells based on silicon – which is very energy intensive to produce – some of the new solar cells are quite different. For example, New Energy Technologies, based in Columbia, Md., has developed plastic polymers that can be sprayed on windows to create a film to produce electricity. Called SolarWindow, the process generates electricity using natural or artificial light, such as fluorescent lighting.