For those of you like me who are interested in using natural, ambient forces to generate energy, I call your attention to The Museum of Unworkable Devices.
It’s a fun and instructive site that discusses the long history of inventions that attempt to defy the laws of physics. It’s worth a look just for the illustrations.
For those actively working on such devices, it could also save you a lot of time.
The seekers after perpetual motion are trying to get something from nothing.
—Sir Isaac Newton