This material is a solid substance that when exposed to sunlight, assumes a charged state that can be maintained for an extended period of time. This means that energy can be stored and used for later if you don’t need it right now. When exposed to a smart burst of heat, the material will then revert back to its original chemical composition, releasing a larger amount of heat in the process.
In some ways you could think of this like those heat packs that when not in use are cold, but when you break the device in the middle it quickly heats up and provides you with warmth on the go. However in this case, the material is thin, almost film-like in quality which scientists think will come in handy in situations to defrost a car’s windshield, dry clothes, or heat your home (maybe placing it on windows so that it can absorb the sun’s energy).
At the moment the scientists are working on changing the tint of the film to be less yellow so that it can be more transparent, and are also looking to boost its heat output by 20 degrees Celsius above the surrounding temperature.