Rain becomes energy resource: Singaporean researchers have created a device that generates electricity when drops fall through a metal tube.
A team of researchers from National University of Singapore has created a simple but effective device a vertical tube that transforms the movement of droplets into electricity.
From rain to electricity: the principle
No complex turbines, no expensive panels: just a stainless steel tube 32 centimeters high and just 2 millimeters wide. When a raindrop enters this channel, trapping air and creating what scientists call “plug flow,” something magical (or better yet, physical) happens. What? The water molecules separate their electrical charges as they descend.
The phenomenon is called precisely charge separation, and although it has been known for some time, no one had ever exploited it in such an “elegant” way for energy generation.
Electrodes at the end of the tube capture this energy, turning it into usable electricity.
Surprising efficiency
The numbers are small but promising: each tube produces about 440 microwatts of power. Doesn’t that sound like a lot? Consider that four tubes were enough to illuminate 12 LED lights for 20 seconds. The real breakthrough, however, lies in the efficiency:
The system converted more than 10 percent of the energy from falling rain into usable electricity, significantly more efficiently than past methods attempting to do the same.
Future prospects for rain energy
Combining multiple sources renewable (sun, wind and even rain) could better balance energy supply, reducing the need for expensive storage systems. It is not just a question of quantity, but also of continuity and complementarity of sources.
The project is still in its first steps, of course; it will be some time before we see these devices on our roofs. Yet, there is something poetic in thinking that rain, often seen, as the enemy of solar energy, could become its ally in the great energy challenge of our time.
