Daniel Connell’s open source DIY wind turbine makes renewable energy affordable.
This is a Vertical Axis Wind Turbine which uses wind energy to drive things like air and water pumps for cooling, irrigation and similar, or an alternator/generator for producing electricity.
The turbine uses the 35-40% mechanically efficient Lenz2 lift+drag design. It is made entirely from scrap materials except for the bolts and pop rivets, and should cost about $15-$30 for the six vane version, which can be made by two people in six hours without much effort.
The three vane version has been successfully survival tested to 80 km/h sustained winds and the six vane version to 105 km. Both will do more, but exactly how much has not yet been ascertained.
For the full tutorial see: http://solarflower.org/tutorial.php?tut=vawt&lang=en&vqual=yt#.U2-a2ChiKbU