Power from rain
According to this report, engineers at the French Atomic Energy Commission have developed a method to harnass energy from rain. The technology is still very immature yet, however.
“Engineers have developed a way of harnessing the force of rain storms to generate power.
Although the technology produces only tiny amounts of energy, researchers believe it could be used in conjunction with solar devices or to switch on car windscreen wipers automatically.
In tests, a team from the Atomic Energy Commission in Grenoble, France, got about one microwatt of power from the smallest water drops.
This is enough to transmit one digital bit of information wirelessly across 10m of air, New Scientist reported.”