...AND CHEAPER...:

Future solar panels might be invisible and plastered on the sides on buildings instead of roofs. A new startup called SolarWindow makes transparent coatings that turn windows into mini power plants.

On a skyscraper, where rooftop solar panels can only provide a fraction of the massive amount of energy that big buildings use, the new windows could power a much larger chunk of an electric bill.

"Rooftop space available for conventional PV is so limited it is difficult to generate meaningful energy for a skyscraper," says John Conklin, the startup's CEO. "SolarWindow, on the other hand, is developing its transparent electricity-generating coatings for the vast surface area of glass available on a skyscraper."

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