Yaron Shenhav and Gadi Grottas, co-founders of Israel’s SolCold, and Hebrew University Professor Guy Ron have invented a high-tech coating that cools down structures when the sun shines. Photons from the sun hit the material which then emits a higher-frequency photon and loses energy.

http://nocamels.com/2017/11/solcold-paint-cools-with-sunlight/