I saw this on tv a few days ago, but apparently, tree's generate power, MIT is looking into how, but the preliminary hypothesis is because there is constantly moving sap, it generates a potentional between the tree and ground, so by putting a nail in the tree and a nail in the ground, you can measure a potential, its very small, but if you had a massive forest, you could probably pull a lot of power, lol.
here's a link I just found on the subject.
**broken link removed**
here's a link I just found on the subject.
**broken link removed**