“Albotherm are developing glass coatings that reversibly transition from transparent to white to reduce solar gain in hot weather, allowing buildings and greenhouses to regulate their own temperature without electrical input. Our coatings are tunable to transition temperatures between 18 °C and 45 °C to create comfortable internal temperatures in a range of climates.“

As discussed in the BBC Bottom Line podcast with Evan “Brexit” Davis

https://www.bbc.co.uk/programmes/m002k4kp