Goodbye, rooftop solar panels…

A transparent liquid sprayed as a film on glass can turn windows into photovoltaic panels that convert sunlight directly into electricity.

Several versions of this technology are wending their way to market. Among the leaders: Solar Window Technologies, which claims its invention – a blend of carbon and hydrogen, with some additional polymers – generates power in direct, shaded or artificial light and could deliver as much as 50 times the electricity of today’s rooftop solar panels. Eventually, the company expects to make a window that you can plug appliances into.

SWT’s film is made from abundant materials, so raw-material costs are low, and it’s designed to be made without high temperatures or many other complexities conventional solar technologies require. The film imparts a neutral tint to a window, but the company also can make the coating in an array of colors.

TRENDPOST: Skyscrapers are the initial market for this new idea. By spraying the acres of windows on all sides of an office tower, the energy saved in a year could pay for the retrofit, an independent study projects. In contrast, SWT says, generating the same amount of electricity to power a 50-story office building would take up as much as eight acres or more of horizontal space. This same installation could reduce carbon emissions by more than 10 times that of conventional solar panels, the company says.

Versions will be commercially available before 2020.