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Molecules Harness Sun’s Energy Even without Sunlight


There is certainly some criticism from detractors of solar energy, because it is unable to work at night or on cloudy days. However, such criticism should be kept quiet to some extent thanks to the latest innovation from the scientists at MIT, who have produced a new material that is able to absorb heat from the sun and keep it for later use just by flipping a switch. The research result is published in the journal of Nature Chemistry.

Such material is made from photo switches: molecules being able to exist in one of two conformations. Given a stimulus, for example, the heat from the sun or an electric current, the photo switch will be changed from one form into the other. This kind of new change is capable of storing the heat energy, until it is instructed by the means of another stimulus to release the heat and turn back to its previous relaxed configuration. That stimulus to allow the molecules to give out the heat can be put under control, thus establishing a system which is able to release heat under very controlled conditions.

Three years ago, this system was first approved theoretically practical in regard to the computer model. Since then the team has spent years to make efforts in creating the functional material, because they need to cram as many molecules as close together for the necessary energy density. Finally, the team found that the structure of the molecules could be packed in tighter than their original thinking, and the functional material had functioned more efficiently than the prediction by the computer model.

As the system can hold in heat, heat can then be outputted if it is needed for cooking or heating rooms. Such innovation would bring big change in daily life for many people living in some developing countries, where there is no enough cooking fuel available and instead some people have to turn burning animal dung, which is harmful in terms of air quality. By a zero-emission system, this solar material could not only preserve the good air quality, but also need to use no limited resources.

Up to now, the system is not regarded to be perfect, because it is unable to convert the heat energy into electricity in a very efficient way. The team will continue their research to modify the present technology to make it easily manufactured for the real application in life.

Source: Nature Chemistry

Image credit: cowgirl_13