Chinese researchers claim “solar like” technology can be used to capture the “abundant” energy in raindrops on a large scale.
The breakthrough hinges on using a device called a triboelectric nanogenerator (TENG), which uses “liquid-solid contact electrification” to generate energy when water droplets hit their surface.
These have previously been shown to achieve an “ultra-high instantaneous power output”, said the team from Tsinghua University in China.
The devices have been around for over a decade and have been a source of great interest in the renewables sector due to their simple structure, low engineering cost and potential for energy harvesting.
Until now, the use of TENGs has been largely limited to generating energy from ocean waves.
There have long been TENGs designed to capture energy from water droplets. However, when these devices are combined their influence on each other causes a big drop in energy generation.
This “severely limits their applications in practice,” said the researchers.
Finding a way of bypassing the inherent mutuality constraints of these sorts of TENGs is therefore of “great significance” for realising “large-scale rain-drop energy harvesting”, the team found.
Now, the researchers report having had just such a breakthrough by using “'solar panel-like’ bridge array generators.” These use a structure that keeps each power generation unit independent of each other.
When the area of the raindrop energy harvesting device is 15cm by 15cm, researchers said their peak power output is “nearly five times higher than that of the conventional large-area raindrop energy with the same size, reaching 200 W/m2, which fully shows its advantages in large-area raindrop energy harvesting.”
They claim the results of this study therefore provide a “feasible scheme for large-area raindrop energy harvesting.”