One of the projects I'm toying with involves harnessing power from swaying trees. I did some "back of the envelope" calculations and concluded that many of our local trees sway in decent winds with around 4000 watts of power in each. (80 foot pine tree at an estimated weight of around 3000 pounds swaying 1 foot per second in the middle.) That kind of power I don't want to ignore, especially since we have dozens of these trees... I post this to open a discussion on this topic.
One key aspect is that the trees do not sway in synch. We have a mix of pine trees and oaks with differing diameters and heights of both of those types of trees. Therefore, the trees are not all impacted by a wind gust in the same way. Watching the trees "out back," it isn't uncommon to see them not only swaying by different amounts, but also swaying in differing directions. Therefore, the approach I've been taking is to make use of the changing gap between the trees. The diagram below shows a wire between the trees that pulls on, and thus spins, a generator shaft when the distance between the trees is increasing. When the gap between the trees is decreasing, a pawl lets the gear freely run backwards and the tension weight takes up the slack.
(The diagram shows the wire being attached to a chain near the generator shaft. This allows for a smaller diameter shaft turning radius than what would be needed to not stress a heavy-duty wire.)
In general, I find this approach attractive for three reasons. First, trees are good for the environment and I don't favor cutting them down to make a clearing for a windmill if a tall-enough tower to reach over the trees (120 foot?) isn't practical or would be against zoning rules. Second, this design lets the generator be on the ground where it is a lot easier to tinker with and, third, you can slave together multiple trees to just one or two generators instead of having to build a genny per tower.
(Efficiently blending together the power from multiple trees isn't easy since the trees have differing speeds and energy. I have an approach, but since that part might be patentable I'm not going to get into that aspect yet.)
I'm about ready to begin a test installation once I figure out a good way of getting to the attachment and first pully locations 50 feet or so up in the tree. 8-[ Has anyone tried something like this? If so, any pointers? If nobody has tried this, are you interested in hearing how it works?
Craig
As ADMIN pointed out this is marginal for being on topic and it seems to have wandered into the realm of wacky ideas. So I am making it read only to keep things topical here.
Editor.