Wind energy

The wind energy converts kinetic energy into electircal and mechanical enrgy. The amount of wind energy depends on the turbine's sizd and the wind speed. It supplies about 10,655 kilowatthours (kWh) of electircity each year, as an average USA household use. However, it has several disadvantages that it kills the birds, and then it causes bad environmental impacts. Also, it produces a noisy like whooshing sounds.

http://www.awea.org/fag/wwt_basics.html

http://www.nrel.gov/docs/fy05osti/37657.pdf