You've decided that in order to lower your electric bills you want to use some form of alternative energy, namely wind power. First of all, congratulations. Due to the high costs of energy, millions of people around that world have started to explore the idea of going green. Your decision will not only help the environment by reducing your carbon footprint and reducing greenhouse gas emissions, you'll also reduce your costs and dependence on foreign oil.
One of the most important questions you'll ask is, how much power can a home wind generator produce? While there is no exact answer to that question, there are some guidelines and rules that you can use to determine the most realistic approximation of potential power that's available at your home location.
The most often used formula for determining the approximate annual energy output for a small wind turbine is:
(Yearly output in kilowatt-hours) = (0.01328) x (blade diameter in feet)^2 x (average wind speed in miles per hour at your location)^3
The simplified formula is: Power = 0.01328(D)^2(V)^3
If we look at the formula, there are two factors that have a significant impact on the energy output. The first is the blade diameter. The energy increase caused by increasing the blade diameter is that of a square function. As an example, if you increase your blade diameter by a factor of 2, you'll see energy output that's 4 times as much.
While this may seem impressive, the more important factor is that of wind speed. Since energy is a cubic function of wind speed the best gains in output can be realized by placing the wind turbine in higher speed winds. For instance, If we double our wind speed at the turbine, our corresponding energy output will increase by a factor of 8! As you can see, wind speed is the single most important factor in small wind turbine energy production.
So rather than spending more money for a generator with larger diameter blades, you'll get better results by utilizing a higher tower to mount your turbine, or a better location with more exposure to wind.
Having been involved in the alternative energy field for over 20 years, D. R. Smith has done a large amount of research and found what he believes are the best wind generator plans and solar cell plans that are designed to be easily constructed by the average homeowner.