“Houses and office buildings account for 75% of electricity use in the United States, and 40% of its energy use overall.” And, all the windows in these buildings can be a problem–letting in heat or cold while leaking cooling or heating energy.
But, several research teams are working on ways to solve this problem.
Newer solar window technologies “absorb almost exclusively invisible ultraviolet (UV) or infrared light.” That leaves the glass clear–a major step forward–while blocking the UV and infrared radiation that normally leaks through it.
By cutting heat gain while generating some power, these solar windows can reduce energy use while also supplying some of the building’s energy needs–plus, they are a step up aesthetically from older solar windows that are more opaque and can have a reddish or brownish tint.
Along these lines, research teams are working on various related technologies; from “developing a UV-absorbing perovskite solar window that can produce enough energy to power on-demand darkening glass that halts intense light in the heat of the day”–reducing the need for air conditioning. To using “luminescent solar concentrators” or “quantum dots” in windows to absorb UV and infrared light, convert it into light that regular solar cells can capture, and shunt that light sideways to solar cells in the window frame. With this technology, solar windows could be relatively inexpensive.
Challenges remain–testing window durability and dealing with the small amount of toxic material used in many solar window technologies. But, down the road, “it’s a safe bet to expect that future buildings won’t draw all their power from the grid. They will generate it, too.”
Read the article (Robert F. Service, Science, June 28, 2018).