Scientists formulate intelligent glass that blocks heat not light: "Reporting in the Journal of Materials Chemistry, researchers reveal they have developed an intelligent window coating that ..reflects the sun's heat ..
While conventional tints block both heat and light the coating, which is made from a derivative of vanadium dioxide, allows visible wavelengths of light through at all times but reflects infrared light when temperature rise over 29 degrees Celsius. Wavelengths of light in this region of the spectrum cause heating so blocking infrared reduces unwanted rays from the sun. The coating's ability to switch between absorbing and reflecting light means occupants benefit from the sun's heat in cooler conditions but when temperatures soar room heating is reduced by up to 50 per cent. ..
"Another consideration, is the colour of the coating. At present it's yellow/green, which really isn't attractive for windows. So we're now looking into colour suppression as a way round this." "
Besides space heating and cooling, I wonder if it would help for photovoltaic concentrating solar collectors, which use Fresnel lenses, mirror systems, or mirror troughs, to reduce the heat stress on the PV components. 11:57:21 PM