This afternoon, between my twin brother and I, we managed to get our 30" cnc bladed windmill on top of a 20 foot pvc pipe tower. As you could imagine, holding a 15 lb windmill on top of a 10 foot pole while you are standing on top of a 4-wheeler in flip-flops is no easy task. Here is the finished product.
During the last 3 days, I spent about 6 hours carving a new 20" blade for my mini motor. My goal was to hit 3000 rpm at 10m/s, which after testing was certainly achievable. The bad thing was that I chose maple as the material, which was way too hard use my spoke shave to cut the darn thing. So I looked around and found a really sharp 1-1/4" wood chisel. This worked much better, especially because the double blade was so small. Here is the finished product, sorry that doesn't show much detail.
As you can see I decided to mount the new blade straight to the old windmill, giving it 4 blades. I found that this helped start up speeds considerably. After watching it for a while, I rotated the front blade so it lined up with the back blade, like an old biplane.
In a couple of minutes, I will have a video uploaded of it in action, and the how much the pole was bending.
On a different note, yesterday I was at Presque Isle State Park and I was watching their 23 foot bergy s 10kw windmill. It was on a 120 foot tower. Sometime later, I went into the building that it was hooked up and saw the power meter. It was reading between 80-100 rpm at 500-900 watts. I would guess the winds to be at about 10mph.
Just up the road, there is another bergy s 10kw windmill on the bluffs overlooking lake erie and i heard that it only produces half the power annually. It must be at least 30 feet higher in the air, but the presque isle one is out by the water where the wind is much better. They must only be a mile apart.
