wind energy based generator

Watch Out For Wind Turbine Power Ratings:The power ratings usually given by the manufacturers for wind turbines are nearly useless, in that they are determined at wind speeds much higher that you will normally see.  A good rough formula to keep in mind in evaluating different wind turbines is                                            Annual Output (KWH/year) = 0.01328 (D^2) (V^3)  Where D^2 is the blade diameter in feet squared, and V^3 is the wind velocity cubed in mph  -- this is the year round average wind speed -- see wind maps below. So, a 10 ft diameter wind turbine in 12 mph average winds might produce about (0.01328)(10^2)(12^3) = 2300 KWH/year  Note that the energy produced is proportional to the cube of wind speed -- having enough averagewind speed is everything in wind turbines.  Use thewind maps discussed below and a wind survey of your site to determine if a wind turbine will actually payoff.  The graph is of the wind energy equation shown above for various wind speeds and turbine blade diameters