Solar energy can now be stored and released as heat when it is needed, thanks to a new material developed by scientists.
The material is able to store solar energy and release is as heat energy on demand. This capacity will be very useful for many applications, including electric cars.
The new material, a transparent polymer film, has been developed by a team of researchers from the Massachusetts Institute of Technology. According to the developers the core of this material is its capacity to store energy in a different form than heat, which dissipates fast, and release it as heat when it is needed.
The research team claims that Sun’s energy can be best stored in a chemical storage which is best suited to keep the energy in for long periods. The most important is to find a system or a material which is able to keep the energy received from the Sun in a stable molecular configuration but also to release it.
The study, published in Advanced Energy Materials journal explains that the key element of such a system or material is for it to have a molecule able to remain stable as it is being charged with energy from the Sun but also when it releases the energy as heat.
Materials having these properties have been previously developed by Professor Jeffrey Grossman from MIT, being named STF – solar thermal fuels. But the STF could only be used in liquid solutions until now, when the MIT team developed a simple method with the help of azobenzenes.
Azobenzenes have the rare property of changing their molecular configuration as light hits them and to go back to their original configuration when stimulated by a pulse of heat, releasing an enormous quantity of heat as they do that. Researchers modified this material, improving its energy density and its responsiveness to the tiny heat pulse needed to activate it.
As the material developed is a transparent very thin film it could have many appliances, such as de-icing car windshields, mirrors and others.
However the team is still working to improve the material’s qualities. They are first working to improve its transparency as for now it has a slight yellowish tinge. But also, as the material can now release enough energy to heat about 10 degrees about the surrounding temperatures, researchers are trying to boost this capacity to reach 20 degrees.
Electric cars would benefit the most from the qualities of such a material as they put a lot of energy into de-icing during the winter.
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