I recently helped out with a school science fair experiment that produced enough power to illuminate a large 1 watt L.E.D. for quite some time. It was a battery made from dirt and a small amount of water....you heard it right...dirt. You can increase votage by trying different liquids such as soda, lemon juice, salty water, vinegar, etc. but it amazed me that you could just use dirt and plain water to make a battery. Google Earth Batteries and you will find a lot of info on it.

Here is a video I used to plan out the science fair project. I used solid copper wire and small pieces of galvanized sheet metal strips. I hot glued them to opposite sides of each ice tray cell then filled each cell with dirt. Connected them in series with jumper wires and added a small amount of water to each cell. I was able to illuminate the L.E.D. for more than an hour when I used vinegar or lemon juice.

I know this isn't much but it is free energy. At least enough to give some light.

Stirling engine with small heatsink can make around 100 watts. Imagine if it were ten times biggerhttps://www.youtube.com/watch?v=5pdqDQwehlk&feature=youtube_gdata_player

Ah, so this isn't the "free energy" nonsense shown on so many YouTube channels. I've seen a few and frankly many are just people trolling and some believe that magnets have mysterious power that can be unlocked. If someone tries to explain this isn't possible through scientific terms, they shut down and say "you're closed minded." You can almost hear them say, "you're just part of the big corporation, man!" LOL The bottom line is conservation of energy.

You mean energy recovery? That's entirely useful. There are so many instances of inefficient devices. If they ever discover room temp superconductors in microchips, there will be a super-jump in technology devices.