If You're Lacking in Sunny Days, These Rain Panels Could Generate Energy Instead
If things are looking a little cloudy, you could be powering your home — with up to 200W per meter square of energy harvesting.
Researchers from Tsinghua University, the China Electric Power Research Institute, the Chinese Academy of Sciences, State Grid Qingdao Power Supply Company, and the Georgia Institute of Technology have proposed an alternative to solar panels for regions where rain is more likely than sunshine — by using triboelectric nanogenerators (D-TENGs) to turn rain drops in to electricity.
“Although D-TENGs have ultra-high instantaneous output power, it is still difficult for a single D-TENG to continuously supply power for megawatt-level electrical equipment. Therefore, it is very important to realize the simultaneous utilization of multiple D-TENGs," explains Zong Li, first author and a professor at Tsinghua University. "Referring to the design of solar panels in which multiple solar power generation units are connected in parallel to supply the load, we are proposing a simple and effective method for raindrop energy harvesting."
Based on technology already used in wave-based energy harvesting systems, the team's approach is simple: an array of nanogenerators attached, just like solar panels, to a building's roof. Where a solar panel array turns sunlight into electricity, though, these D-TENG arrays capture the energy from falling drops of rain — making them a better bet in regions where the number of rainy days are vastly greater than the sunny ones.
The team's approach seems considerably more scalable than alternatives, boasting a near-fivefold increase in the amount of energy that can be generated in a given area.
"The peak power output of the bridge array generators is nearly five times higher than that of the conventional large-area raindrop energy with the same size," Li claims, "reaching 200 watts per square meter, which fully shows its advantages in large-area raindrop energy harvesting. The results of this study will provide a feasible scheme for large-area raindrop energy harvesting."
The team's work is published in the journal iEnergy under open-access terms.