Harnessing clean energy from rainfall in urban settings is becoming a reality. A team of researchers has developed a system that generates electricity from raindrops using a plug flow in a vertical tube. This innovation, detailed in ACS Central Science, could power 12 LEDs and offers a clean energy solution for urban environments, such as rooftops.
Siowling Soh, the study's author, explains, "Water falling through a vertical tube generates considerable electricity using a specific water flow pattern: plug flow." This method could enable the collection of rainwater energy to produce clean, renewable electricity.
The system converts over 10% of the water's potential energy into electricity. Compared to a continuous water flow, the plug flow produced five orders of magnitude more electricity. Researchers believe the system could function effectively with real rain, making it ideal for urban settings like building rooftops.
The device's simplicity is key: water drips from a metal needle into a 32-centimeter-high, 2-millimeter-diameter vertical tube. The drops create a plug flow, with short water columns separated by air pockets. As the water descends, electrical charges separate and are collected via wires at the tube's top and base.
Experiments showed that using two tubes simultaneously or sequentially doubled the energy output. Four tubes powered 12 LEDs continuously for 20 seconds. This plug flow system could complement other renewable energy technologies in urban environments.