Despite solar cells and solar panels having proven their effectiveness to efficiently capture solar energy at a very low cost, they’re still limited to working on a sunny day.
This means in the simplest form when there is no sun, there will be no power. In areas where cloudy or rainy weather is more common solar cells do not, on the surface, appear as the best choice for energy production. So it would be great if we can generate energy even in cloudy or rainy conditions.
Well, it appears as if the solution to this problem has been found! Chinese researchers from the University of Soochow have developed hybrid solar cells that can also capture energy from raindrops. Combining two polymer layers (to form a pseudocapacitor or triboelectric nanogenerator, TENG) on top of a solar photovoltaic cell, results in the friction of the raindrop falling generating a static electricity charge. “Our device is able to generate electricity in any daytime weather conditions” said Baoquan Sun, Researcher at Soochow University. “In addition, this device even provides electricity at night if there is rain.” .
In fact, researchers have imprinted the two polymers, PDMS and PEDOT:PSS, with grooves and added them to a photovoltaic cell to form a TENG. The first polymer has an improved TENG performance thanks to the grooves. Furthermore, the PEDOT:PSS polymer acts as a mutual electrode for both the TENG and the solar cell as it conducts energy from the first to the second. Since the polymers are transparent, the solar cell is also able to create energy from the sunlight .
Similar devices have been studied in previous areas of research. As a matter of fact, a TENG has been added to an existing solar cell in order to create a device that generates energy from the motion of raindrops. Whilst the effectiveness of the solution has been proved, these devices take up a lot of space, as they’re often very complicated to manufacture. On the other hand, the Soochow University team has simplified the device to make it much more compact and efficient.
“Due to our unique design, the device becomes lightweight” said Sun. “In future, we are exploring integrating these into mobile and flexible devices, such as electronic clothes. However, the output power efficiency still needs to be improved before practical application.” .
Despite this, scientists hope to develop their first prototype within five years.
Mariem, Consultant, Leyton France