MIT researchers turn everyday windows into solar panels

Computerworld - Researchers at MIT have created a new way to harness the sun's energy -- by turning windows of big buildings into solar panels.

The new technology, dubbed "solar concentrators," harvests light over a wide area such as a window pane and then concentrates or gathers it at the window's edges, said Marc Baldo, a professor at MIT and head of the effort. He talked about the project in a video available from MIT.

Baldo added that the technology also could be used to soup up more traditional solar panels, increasing their efficiency by 50%. Solar panels are semiconductors (often found on rooftops) that transform sunlight into electricity.

"The sun is an inexhaustible source of clean power. The major impediment to widely deployed solar-power systems has been cost," Baldo told Computerworld. "If you have a big building, you should be able to generate 50 to 60 watts per square meter. The thing with windows is you need a large area of windows. It makes a lot of sense with tall buildings or really big buildings."

With companies looking to go green and cut down on the amount of money they're spending on energy, solar power is gaining attention. And this advancement could help major buildings with lots of windows generate some of their own electricity.

Instead of covering a roof with expensive solar panels, the new solar cells need only to be around the edges of a flat glass panel. The concentrated light increases the electrical power obtained from each solar cell by a factor of more than 40, noted Baldo.

To create the concentrator system, researchers mix multiple dyes that they basically paint onto a pane of glass or plastic. The dyes absorb light across a range of wavelengths. The energy then is pushed out to the edges of the pane, where it's stored in solar cells there.

Baldo noted that the overall concept has been around since the 1970s but researchers then didn't have the technology to move the energy from the middle of the pane to the edges without losing a lot of it along the way. The MIT researchers relied on different mixtures of dyes and used them in different ratios to give them greater control over light's absorption and movement.

While the work is being touted as a way to turn windows into solar power generators, Baldo said that traditional solar panels on rooftops still provide the most energy. Using the solar concentrators in window panes is a less-expensive alternative.

Because the system is relatively simple to manufacture, MIT reported that it could be implemented within three years.

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