Saturday, December 12, 2009
My idea of a good time
We took a final, just-for-fun, field trip in our Wind Assessment seminar. This is a one-credit class in our Sustainability Design and Technology program in which students have learned how to measure wind using anemometer systems, how to assess wind measurements statistically and how to use the results to cost out the economics of turbine installations (of any size, small, medium, large), and a little bit about how to study turbine noise and planning problems.
We went to see local turbines spinning in the recent gale. First we saw our own small Air X model, which is hooked in parallel with a solar system, and has a cut-in voltage of 12.5, and so hasn't turned much this fall. A few non-sunny days and a bit of wind were enough to fix that, and it was spinning flat out.
Then we went to see Ervin's Amish wind compressor. It was shut down, having been working all day and the air tank being well above its cut-off pressure, but Ervin bled off some air and we got to see the pressure regulated furling system kick in. It worked beautifully.
As the air bled off, the air piston pressure reduced, allowing the tail vane to spring back into place, turning the turbine into the wind. It then spun up nicely, sounding a bit like a steam engine, only not so loud that you'd hear it from 500 feet away.
There is an Unity College anemometer on Ervin's tower, and we were pleased to see that now his compressor is "broken in," the cut-in speed is 10 mph. His tower was working well, too having survived a recent 45 mph gust, according to the anemometer.
We took pictures for Ervin to use in a sales brochure, and for Eli, another Amishman from the Schwartzentruber sect, who had some well-bred Baskir Curly Horses for sale that he wanted pictures of.
We were having so much fun hanging out at Ervin's farm, we never made it to the next two turbines on our list.