The energy generated when raindrops fall can be captured and converted into electricity. This process uses the kinetic energy of moving water to generate electricity, which is considered a miniature form of hydroelectricity. However, practical use is limited by the challenge of scaling this technology on a large scale.
To capture the energy of rain, the experts use a device that helps electrify liquid-solid contact called a triboelectric nanogenerator (TENG). The problem, however, is that the droplet TENG (D-TENG) has a technical limitation in connecting multiple machines together, reducing the overall power output.
A team from Tsinghua University has come up with a way to tailor D-TENG devices to solar cells to make rain energy harvesting more efficient for large-scale deployment.
Zong Li, a professor at Tsinghua University, China, said, “D-TENG has extremely high output power output, but for a single D-TENG to provide uninterruptible power to megawatt-level electrical equipment is not extremely difficult thing. Therefore, it is necessary to use multiple D-TENGs simultaneously.
When multiple D-TENGs are connected, the upper and lower electrodes of the collector plate will have an unintended coupling capacitance that reduces the output power of the D-TENG. The team proposed using linked plate generators similar to solar cells, using the bottom electrodes of the energy collector to reduce the effect of capacitance.
The results show that the linked plate generators have a maximum power output of 200 watts per m2, nearly 5 times higher than the amount of electricity collected from rain by traditional equipment of the same size. This offers a possible solution for large-scale raindrop energy harvesting.