use their technology to create energy with raindrops

In their efforts to improve and expand solar panels, researchers have tried new materials, designs, positions, strategies to make them more sustainable, and even translucent and ceramic plates that allow us to dream of energy-generating windows, facades, and roofs. green electricity… However, Tsinghua University in China went even further and offered plates with a completely different way to generate renewable energy.

Cause? They use solar cell technology to harvest energy from raindrops. His work has just been exhibited at iEnergy.

Energy with drops? That’s it. When raindrops fall from the sky, they can produce a small amount of energy that, when used properly, is converted into electricity. “They contain a lot of renewable, kinetic and electrostatic energy,” explains Zong Li, a professor at Shenzhen Qinghua University, along with other colleagues with whom he signed the article. iEnergy. In its own way, it is a “small-scale version” of a hydroelectric power plant that uses the speed of water to produce kinetic energy, and then, with the help of a turbine and generator, converts it into mechanics and, finally, into electricity.

While scientists have been thinking about ways to generate clean and renewable energy from the drops that fall from the sky, it hasn’t been easy for them. And for a very simple reason. Although they have already made some progress, their large-scale development remains a challenge. “Its use is a hot topic of research,” they note.

What is the problem? Scientists already have a device known as a triboelectric nanogenerator, or TEN, that can successfully extract energy from raindrops. How? With “electrification by liquid-solid contact” technology, which also allows the use of wave energy and other forms of triboelectric generation, which is usually achieved through friction between two surfaces. So far everything is perfect. The problem arises when using drop-based heating elements (D-TENG). And this is so because of its technical limitations.

“Although D-TENGs have very high instantaneous power output, it is still difficult for a single D-TENG to continuously power megawatt-level electrical equipment. It is very important to achieve the simultaneous use of several D-TENGs,” explains Li. Easy to say, not so easy to put into practice. When multiple D-TENGs are connected, there is an unintended effect between the top and bottom electrodes of the panels that reduces power output.

And what are they looking for in China? fix it. “When energy is collected from dense raindrops, and not from one, a more rational structure is needed to exclude the mutual influence of individual generating units,” the Chinese researchers explain in their article. iEnergywhere they accurately reveal their solution: a bridge grid generator (BAG) “like a solar panel”.

With a bottom electrode array and a reflow bridge structure, BAGs aim to “minimize the drop” in output power in large power applications. And they weren’t bad. When the droplet coverage is 15×15 cm2, the BAG’s peak power output reaches 200 W/m2, “which is great for a possible industrial approach,” they say.

What are the benefits of solar panels? When talking about their work, Li and his colleagues emphasize that their generator (BAG) is “like a solar panel,” a slogan – the quotation marks actually belong to them – which they even repeat several times in their article. “They use the bottom array electrode (ALE) and the bridge array generator to make each power generation unit independent from each other, and eliminate the influence of the electrodes, so that the output power of the large-scale D-TENG remains high. and is independent of size.

The Chinese team is convinced their results could pave the way for “large-scale” raindrop harvesting. With a device size of 15×15 cm2, its design achieved a maximum power output five times higher. “Referring to the design of solar panels, in which several generating units are connected in parallel to power the load, we propose a simple and efficient method for obtaining energy from raindrops,” adds the professor from Tsinghua University in Shenzhen.

Images: Oregon Department of Transportation (Flickr) And iEnergy-Tsinghua University Press

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