Still, don't assume anything about wind speed. A small difference in average speed or consistency equals a much bigger difference in production. In our area, everybody loves to bitch about the wind. Some people move away because they can't stand the blowing. It seems omnipresent until you put up a turbine. :-) Here's a local story that's typical of overestimating a wind resource
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(features some metal content). Granted, the prep work for that project was so poor that it bordered on silly, as evidenced by the contractor's confusion about the difference between power and energy.
Hmmmm. If there aren't a lot of others in your area already doing it, be very suspicious. The bank sure will be. If there ARE lots of people in your area doing it, ask them.
Sounds as though you have already talked to your utility. Ask them for names of others who are already connected. I assume that "work with me" and "under 40Kw" means that you want to sell as much power back at RETAIL as you can. So, you are into cost avoidance, not the power production business. $500K sounds like a lot of money to invest for a small return. And, if you design a system that PEAKS at 39.9Kw, you won't be selling them a whole lot of power anyway, since most of the time you'll probably be running at a lot less than peak. I don't think that's what you want. You should be considering a unit that puts out a lot more than that, with (acceptable to the utility) electronic controls that make sure you never deliver over 40Kw, if that's what they demand. In our area, we can sell (retail, or "net metering") up to 25KW on a single phase line (us) or up to 75KW on a 3 phase line.
I think you need to contact people who do a lot of wing installation. If you ar thinking of generating DC and then using an inverter to feed the utility, I can see where your high costs could be coming from in that power range. But, if you can get the utility to buy into an induction generator system (of which there are lots, in certain places like central Minnesota), the hook up becomes MUCH less expensive.
There is a photo series on the web of a guy building his own wind generator. He starts with a car axle/spindle assembly, and mounts a stack of two discs to the studs. He gets some large rare-earth magnets and glues them to the discs in an alternating N-S pattern. He winds little trapezoidal coils, wires them up in a 3-phase sequence and then embeds them in fiberglass and epoxy. When the whole thing is assembled, the coil plate is between the two magnet-covered discs. Then he mounts a "prop" to the assembly, puts it on a swivel and it is ready to go on the tower. I was VERY impressed with the simplicity of the design, and it looks like he got pretty much everything right on it.
If you can't find this with a little web searching, I'll see if I can locate it again. This unit, in single quantity, is a LOT smaller than
40 KVA, and would need a grid-tie inverter, but could be built pretty cheaply, maybe a couple hundred $ per unit, plus time. After the first module, I think you could make them fairly quickly. The basic design could be easily scaled up (truck front spindle, bigger discs, more magnets and coils, bigger prop, etc.) I'm guessing the units he was building were good for a several KVA each.
Ditto for my first (and only) snowmobile. Snowless winter.
Wes
-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller
A wealth of good info from some real git-er-done people. Here's their largest project
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with a 20' rotor. Check out the foundation anchors on page 5. Should be a puzzlement to future archaeologists. :-) Karl would need 8 such turbines! Scaling it up might be possible to reduce the number, but any subsidies and buy-back schemes almost certainly require certified equipment.
On Tue, 14 Jul 2009 16:53:34 -0400, the infamous "Buerste" scrawled the following:
Oh, no. The little jobs can't create nasties for sale. So sorry!
-- Mistrust the man who finds everything good, the man who finds everything evil, and still more the man who is indifferent to everything. -- Johann K. Lavater
Rules and regulations. Under 40KW, hook up to single phase transmission lines and buy any extra at retail rate - $0.085. Over 40KW bring in 3 phase transmission lines and sell any extra at wholesale $0.015
Had a nice long talk with the state electrical inspector for wind power today. Very informative and i got a list of top local contractors.
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