WorldChanging has a short item about a home-use electricity-generating windsail designed by engineers at the Lawrence Berkeley National Laboratory in the US and the Makeyev State Rocket Center in Russia. Unlike a horizontal-axis wind turbine, this one is supposed to be quieter and less hazardous to birds. As you can see from the table below, you need a pretty brisk wind to keep even one light bulb burning.
Condition |
Turbine Output (watts) |
Annual KWh |
<5 m/s wind |
negligible |
negligible |
5 m/s |
87 |
764 |
8 m/s |
358 |
3130 |
10 m/s |
700 |
6113 |
12 m/s |
1209 |
10564 |
Class 2; 30M AGL |
281 |
2457 |
Class 3; 30M AGL |
401 |
3500 |