Researchers create new “smart windows” that block out the sun and turn sunlight into electricity

Have you ever heard of windows that can turn from transparent to opaque, and thereby block out light from the sun? So-called smart windows have been around for quite some time now. Now one research team says they have made a quiet breakthrough that will allow for the construction of highly efficient smart windows that can also successfully generate solar energy at the same time.

Using much of previously available research and methods as inspiration, a team of researchers from the University of California led by Peidong Yang has managed to come up with a solution that creating smart windows with none of the conventional drawbacks. For reference, a standard smart window is known to suffer from what is known as the methylamine chemical reaction, which causes inconsistent performance in perovskite-based solutions. The new method not only improves upon old solutions, but it also avoids these complicated drawbacks.

According to a report on the new study, perovskites are the major key when it comes to creating smart windows. It is said that perovskites are the ones that grant smart windows with the ability to stay transparent in cool temperatures but turn dark once the heat gets turned up by sunlight. It’s so essential, in fact, that companies like Boeing have already been using it for at least over four decades.

It is said that the best-known perovskites can convert more than 22 percent of the energy found in sunlight to electricity whenever they are in use. This is an impressive feat, considering that silicon solar panels only manage to convert a little bit more at 25 percent. The challenge for researchers then is to come up with a solution that not only works as a proper smart window but also retains this somewhat acceptable level of solar energy efficiency.

What the researchers led by Peidong Yang created is nothing short of amazing. In a research paper that was published in the journal Nature Materials, the research team lays out the details of their experiments, which they say has resulted in a new cesium-based perovskite solar window. They say that this new type of solar window can turn opaque in response to the heat of the sun and then go back to being transparent when the sun goes down, or the temperature gets cool enough. At the same time, the new cesium-based perovskite window is also said to produce electricity from interacting with sunlight, but not suffer from a methylamine reaction.

All of this is to say that there may finally be a working solution for smart windows that can also gather solar energy efficiently. According to the report on the study, the new type of smart window the researchers created can switch back and forth between opaque and transparent repeatedly without suffering a drop in performance. And as one expert on the subject states, it’s nothing if not an elegant solution.

“It’s an attractive idea that you would have the solar cell capability and the smart window at the same time,” said Michael McGehee, a materials scientist from Stanford University. As someone who studies both smart windows and perovskite solar cells, he has seen numerous solutions but still found this new one quite commendable. Although they are not perfect, the researchers behind them are looking for ways to improve them for future uses. For now, the focus is on improving the solar conversion efficiency. And once it gets past a certain level of performance, it may just be the next best thing in the world of solar power for the home.

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