energy production
Question:
I built a simple windmill our of wood, 8 blade in a sort of flower design. I got the design off a real lawn decoration. My question is what kind of motor should find or purchase to put on it to power an LED or charge a small battery? It is only about 11inches in diameter and I live in WI so i dont know what kind of rpm’s it would get, but im open to any suggestions.
Response:
> I built a simple windmill our of wood, 8 blade in a sort of flower design. > I got the design off a real lawn decoration. My question is what kind of > motor should find or purchase to put on it to power an LED or charge a small > battery? It is only about 11inches in diameter and I live in WI so i dont > know what kind of rpm’s it would get, but im open to any suggestions.
I’d suggest that if you’re going to invest the time, you might as well go with a design that’s better suited for power generation than decoration. An 11 inch drag-type windmill would, I’m guessing, be doing well to get a couple of watts. http://www.picoturbine.com has lots of good information, and parts that you can buy for the purpose. (I’m not affiliated with them, I’ve just bought stuff from them in the past and got good information and service). Dave Hinz
Response:
also see http://www.windstuffnow.com/main/newpage5.htm — Steve Spence Subscribe to the Renewable Energy Newsletter & Discussion Boards. Read about Sustainable Technology: http://www.green-trust.org
– Hide quoted text — Show quoted text -> I built a simple windmill our of wood, 8 blade in a sort of flower design. > I got the design off a real lawn decoration. My question is what kind of > motor should find or purchase to put on it to power an LED or charge a small > battery? It is only about 11inches in diameter and I live in WI so i dont > know what kind of rpm’s it would get, but im open to any suggestions. > I’d suggest that if you’re going to invest the time, you might as > well go with a design that’s better suited for power generation than > decoration. An 11 inch drag-type windmill would, I’m guessing, be > doing well to get a couple of watts. > http://www.picoturbine.com has lots of good information, and parts > that you can buy for the purpose. > (I’m not affiliated with them, I’ve just bought stuff from them in > the past and got good information and service). > Dave Hinz
Response:
> also see http://www.windstuffnow.com/main/newpage5.htm
Thanks for that, Steve, great link. Dave Hinz
Response:
> I built a simple windmill our of wood, 8 blade in a sort of flower design. > I got the design off a real lawn decoration. My question is what kind of > motor should find or purchase to put on it to power an LED or charge a small > battery? It is only about 11inches in diameter and I live in WI so i dont > know what kind of rpm’s it would get, but im open to any suggestions.
Nothing wrong with that model of yours, in fact they look kind of pretty, like the classic American Windmill they used to use for water pumping. It’s low efficiency, so don’t expect much useful power from it. It’s one of the rotor types that has a low tip-speed to wind-speed ratio (TSR), so it’ll rotate fairly slowly. Try a bicolor LED across a couple of the windings and you’ll get a nice red-green alternating flash as the rotor spins. For an easy low-RPM electric generator, use a small stepping motor – the smaller the step angle the more efficient it will be at low RPMs. Technically, it will be a 2-phase permanent magnet alternator, so you need to add a pair of full-wave rectifiers for DC. Not as good as a 3-phase for ripple, but a lot better than single-phase. There are a couple of web pages whose URL I forget that explain in detail how to do this – search on "stepper motor" plus "alternator". The TSR range for useful power will be narrow for this blade design, so without fancy electronics it’s best to keep the mechanical loading fairly light and let the windmill find its own speed. Good luck, Gerry
Response:
> I built a simple windmill our of wood, 8 blade in a sort of flower design. > I got the design off a real lawn decoration. My question is what kind of > motor should find or purchase to put on it to power an LED or charge a small > battery? It is only about 11inches in diameter and I live in WI so i dont > know what kind of rpm’s it would get, but im open to any suggestions.
Check out http://otherpower.com/otherpower_experiments.html
Response:
If you can find a way to put the led’s on the tips of the blades it’ll make pretty circles at night. have the windings on the blade hub spinning with the blades and put the magnets on the body of the thing. or set up some sort of brush assembly to two rings on the shaft. a small dc motor should have some brushes you can use by the way a dc motor just from a toy car or whatever around one inch across is big enough to run an led. rip up an old walkman. Peter
– Hide quoted text — Show quoted text -> I built a simple windmill our of wood, 8 blade in a sort of flower design. > I got the design off a real lawn decoration. My question is what kind of > motor should find or purchase to put on it to power an LED or charge a small > battery? It is only about 11inches in diameter and I live in WI so i dont > know what kind of rpm’s it would get, but im open to any suggestions. > Check out http://otherpower.com/otherpower_experiments.html
