Solar power is a great source of renewable energy, but it’s only effective in areas with plenty of sunshine to feed the cells. This leaves much of the world out in the cold on the solar revolution. That may change soon, however, as scientists in France experiment with a new system to capture energy from rain and turn it into electricity.

Scientists at CEA/Leti-Minatec, an R&D institute in Grenoble, France have developed a system that recovers the vibration energy from a raindrop using a PVDF (polyvinylidene fluoride) polymer, a piezoelectric material that converts mechanical energy into electrical energy. When a raindrop impacts the PVDF, the polymer starts to vibrate, and electrodes embedded in the PVDF are used to recover the electrical charges generated by the vibrations. The scientists built a testing apparatus and were able to control drop size, frequency, and height, as drops of water fell and impacted the piezoelectric material.

The system can generate one microwatt of continuous power on the low-end, while simulations showed that a single large raindrop might generate up to 12 milliwatts of power. In general, the larger the raindrop, the more electricity that is generated. In the future, the scientists plan to develop a method to store the electrical power to provide a steady current for practical use.