Homemade Windmill
As the price of electricity continues to climb, many people begin to ask what they can do to lower their energy bills. A Homemade Windmill should be considered as an option to decrease your energy bills.
Making your own handmade windmill sounds like a difficult task, but not if you break it down into manageable steps. A windmill is made of a rotor, a tower, a generator, an inverter, and some electrical connection to your home.
A homemade windmill requires a tower with the height depending on the surrounding terrain. While a tower can be the most expensive part of a windmill, it can reduce the diameter of your wind turbine since the higher you build, the more power you can extract with the same size wind turbine. Generally the windmill should sit above all other obstacles including homes, trees, and other structures in order to maximize the energy your windmill can produce. This is because the atmosphere has higher wind velocity at greater heights due to the friction the homes, trees, and hills provide. You could opt for a less expensive tower, but then you will need to build a larger diameter wind turbine.
Most windmills are horizontal axis wind turbines with a rotor that is forced to face into the wind with a tail fin. The rotor is usually made of metal, wood, plastic, or fiberglass and turns a shaft connected to your generator. The rotor should be large enough to power your house under average wind conditions for your home if you wish to truly live off grid. You can determine the wind density for your house by visiting www.nrel.gov and looking for wind maps. Once you determine the wind density in Watts per square meter, you can algebraically solve for the area of your rotor in square meters. For example, if your electric bill says your home used 2000 kiloWatt-hours in one month, this means you use on average 2000 kWh / ( 30 days * 24 hours/day ) = 2.7 kW or 2700 Watts. So if your home is in an area with a wind density of 200 W/m^2, then you need a wind turbine with an area of 13.5 square meters. Using the formula for an area of a circle, this gives a diameter=sqrt(4*area/pi)=4.15 meters. This might seem like a large diameter, but really each rotor blade will be less than seven feet in radius.
You will also need to find a generator that can produce enough electricity for your home. Using our example above, this means you would need to find an electric motor that requires at least 2700 Watts of power, and an inverter that is capable of converting this amount of power into the 120 Hz AC power that your home expects. It can be difficult to match the generator speed to your windmill. Industrial windmills actually use a gearbox to best match the speed, which may also be necessary depending on the availiable generators.
While your homemade windmill may break from time to time, you will be able to easily fix it since you have made it yourself and know the details of your windmill. If you do build a homemade windmill you will have saved yourself ten to fifty thousand dollars. Of course the ultimate payoff comes when your electric bill is super low and you can bask in the satisfaction of doing it yourself and saving yourself money.
