Residential wind turbine systems can reduce your power bills and, if connected to a battery, can supply electricity during power failures. Depending on where you live and how much your electricity costs, installing some wind power may be cost-effective for you. Before deciding on possible systems, you have to know how wind turbines work to be sure you get the right equipment for your needs.
The wind turbine uses aerodynamic blades to extract kinetic energy from wind. When air passes over the blades, it pushes them to rotate around the turbine's shaft, turning a generator that produces electricity. At the far end of the turbine casing from the blades, a vertical tail panel keeps the turbine pointing into the wind. You have to mount the turbine on a tower that reaches high enough for a strong, steady wind flow. The tower either has to be sturdy enough to climb or has to include a mechanism allowing you to lower it for maintenance and repair of the turbine.
Wind turbines produce a lot of power in strong winds, but there are times when your location sees little or no wind. The best approach for determining how much power a wind turbine can generate is to take the manufacturer's ratings for specific wind speeds and calculate how much power the turbine will produce, based on the average wind speed of your location. Wind maps, such as those published by the U.S. Department of Energy, give average wind speeds for your area and let you determine the average power you can expect from a particular wind turbine.
Locating the wind turbine at sufficient height and away from obstacles is critical for optimum performance. The wind turbine is very sensitive to turbulence and wind eddies, and the wind is stronger at higher elevations. A good rule of thumb is to locate the wind turbine at least 30 feet higher than any obstacles within 300 feet. The U.S. Department of Energy wind maps for residential wind turbines presume a turbine elevation of about 100 feet. If you mount your turbine at lower elevations or near obstacles, it may not deliver the power specified by the manufacturer.
The power from the wind turbine has to be conditioned to be suitable for use in your home. You need an inverter to match the turbine output to the power needed for your household loads. The rest of your wind turbine system depends on whether you plan to connect the wind turbine to the grid. For grid-connected systems, you need a transfer switch to isolate your system from the grid in case of a power failure. For stand-alone systems, you need batteries to store excess power for use during periods of low wind. This additional equipment lets the wind turbine work with your existing electrical system to reduce energy use.