Solar Window

 

Solar Window
Solar windows are windows that function as solar panels to harvest the sun’s energy and convert it to electricity. Building owners can purchase solar windows to replace existing windows or buy solar film to retrofit existing windows.

In the past, materials scientists have embedded light-absorbing films in window glass. But such solar windows tend to have a reddish or brown tint that architects find unappealing. The new solar window technologies, however, absorb almost exclusively invisible ultraviolet (UV) or infrared light. That leaves the glass clear while blocking the UV and infrared radiation that normally leak through it, sometimes delivering unwanted heat.


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. SolarWindow, on the other hand, is developing its transparent electricity-generating coatings for the vast surface area of glass available on a skyscraper.”

Installed on four sides of a 50-story building, the windows could cover about six acres of glass and generate 1.3 gigawatt-hours of energy. The company calculates that the system could fully pay for itself in a year, far faster than rooftop solar



It isn’t the first transparent solar technology in development, but it would generate more power than predecessors. A different solar glass, from Michigan State University researchers, has a power conversion efficiency of just 1%. SolarWindows, which use multiple layers of liquid coatings, produce 53% more power, according to an independent test by the National Renewable Energy Laboratory.


The technology they use–a particular type of organic photovoltaics–also works in less sunny spots and even in shade, unlike normal solar panels. “Conventional PV modules require nearly direct, intense sunlight before they start outputting energy.

In the U.S. alone, an estimated half billion square feet of glass is installed on tall buildings every year. Eventually, the technology may also show up in other products, like glass on the front of a mobile phone that could power the electronics inside.