Big wind turbines are sprouting up and tying into utility grids all over the country. More power to 'em. As for small wind turbines that are used to charge DC battery banks, we've seen a lot of them at work on sailboats, but only a few used on home sites or jury-rigged on parked RVs.
Success of a small turbine for home use depends on how hard the wind blows in your area year-round, whether you're sited well enough to take advantage of the wind, whether you can mount the thing in a place where the noise won't bother you and the neighbors, and how interested you are in making batteries and DC power part of your life.
Here's the U.S. Department of Energy's page on wind power: Wind Energy Technologies.
One of the most common small turbines is the 400-watt Air-X, made by Southwest Windpower. In fact, the company says it's "by far the world's number one selling small wind turbine." The Air-X starts producing current at 8 mph. of windspeed. It's a bit hard to read the power curve on the PDF spec sheet, but it looks like it produces 5-6 amps at about 15 mph.
Small, fast-turning turbines like this are, to my ear, pretty noisy when the wind pipes up. But noise is a subjective thing, and much depends on where the thing is located.
There are plenty of competitors. If the expertise of the dealer is an indication of a good product, then the KISS High Output Wind Generator deserves a look. It's made in Trinidad and and distributed in North America by John Gambill of Hotwire Enterprises. The KISS is engineered to work well at relatively low windspeeds. For example, it kicks in at at about 6 mph. and produces about 4.5 amps of current in 10 knots (11.5 mph) of wind, and 10 amps at 15 knots (17.3 mph.)
If you're more serious and you have some elbow room, you can take advantage of the larger stand-alone wind turbines, like those made by Bergey Windpower Company.
If you have experience with stand-alone wind turbines, click the "Comments" link below and fan the knowledge.
~ Doug Logan, New Energy Watch