I know very little about electricity-generating windmills, so my comments here may seem naive to those who do. However, I know that some very smart scientists sometimes read my web page, and I thought perhaps my comments might prompt their more-knowledgeable replies. I started thinking about this during the recent Colorado wind storms, when I noted to my wife that it’s too bad we can’t harness some of that violent air flow.
As far as I can tell, there are two big problems with windmills. First, they work only at certain wind speeds. If the wind is too slow, they don’t work. If the wind is too fast, they either break or don’t work. Second, they directly turn a generator which in turn charges batteries. (At least this is how the windmill worked that I’ve seen close-up.) Batteries are expensive, limited in capacity, limited in life span, and inefficient in that they leak energy. (If they’re not hooked up to batteries, you’ve got to somehow get that energy to someplace it can be used, which creates a new set of thorny problems.)
It occurred to me this morning that it might be possible for a clever engineer to solve some of these problems with an old-school approach: mechanical energy storage. Basically what I have in mind is a big spring-loading system, or maybe a flywheel.
It seems to me that if somebody could get a windmill to do two things at once, it might work pretty well. The first thing is to capture energy at all different wind speeds. Maybe the traditional propeller mill can accomplish this, or maybe what’s needed is something more cylindrically shaped attached at two points. The big key is a geared system so that the mill can always spin (above a certain minimal wind speed) within a reasonable range. The second thing is to store the energy locally in some sort of mechanical-storage device. (Hell, it could just slowly lift a giant boulder in the air or something.) This mechanical storage system in turn runs the generator as needed. Also, you could hook up other moving things to charge this device.
I think part of what made me think of this are the giant mechanical clocks in Neal Stephenson’s Anathem. That book also makes me sensitive to two points: most ideas are wrong (including most of the ones in that book), and the good ones are hardly ever original. I suspect one or the other is the case here, but nevertheless I thought I’d give it a go to see what more “praxic”-minded people have to say about it.