Contributing Monkie G Living Staff Monkies
Published on May 25, 2008
Energy from rainwater? If you read my blog on harvesting rain, you’re aware of the many possibilities nature provides to supplement our insatiable need for water. But some scientists at Europe’s Atomic Energy commission have taken the idea of utilizing rainwater a step (or ten) further – they’ve figured out a way to harness the energy released as a drop of rain hits a hard surface.
It’s quite simple really. A raindrop has absorbed a significant amount of energy through evaporation. That energy is increased by its height above the ground (anyone remember Potential Energy from Earth Science?). As the drop becomes too heavy to stay in a cloud, the drop begins to realize its potential, and as it hits the earth, it releases that energy in the form of mechanical force. Scientists are using piezoelectric material to capture that force and turn it into electricity.
Unfortunately the electricity from one raindrop is pretty small – about 12 milliwatts – so it will take quite a bit of rain to produce usable electricity. I’ve never bothered to count the raindrops hitting my roof during a rainstorm, but I’m pretty sure the watts would add up quickly, even in a short storm.
And imagine the energy released by a hailstone.
All that’s left now is to combine solar arrays with piezoelectric devices that can be used as roofing material. Then every household should be able to produce most of its own electricity.
What does this prove? That potential energy is everywhere around us, not just in fossil fuels. Keep in mind that the sun is responsible for every bit of energy we have “discovered.” The sun once supplied energy for the dinosaurs and then aided in their decomposition. In this example, it evaporates the water that turns into raindrops storing energy in the clouds. But the sun’s energy also threatens to destroy as we continue to pour energy-trapping gasses into the atmosphere.