Turbine

The turbine is the spinning part of the wind turbine system that generates the electricity. The turbine consists of:

• Blades - Most wind turbines have three blades, usually made of a plastic fiberglass composite.
• Rotor - The blades are connected to a double rotor assembly. The blade rotor spins when the blades catch the wind. The magnet rotor spins around a magnetic alternator, creating a magnetic field and producing an electrical charge.
• Controller - The controller converts the raw electricity to direct current (DC) power and sends it either to a battery or an inverter.

Batteries

Batteries are optional. Most modern residential wind turbines are tied directly to the utility grid and don’t use batteries, but if you have a stand-alone wind turbine system, or you want back-up in case of power outages, batteries are needed for storage.

Inverter

The inverter converts DC power from the batteries to active current (AC), used in your home and on the utility grid.

Bi-Directional Meter

Your utility company will install a bi-directional meter that tracks the amount of energy your wind turbine system produces and the amount of energy your household consumes.

Swept Area

The swept area is the circular area covered by the turbine’s spinning blades. If your rotor assembly has a diameter of 12 feet, the swept area is 113 square feet.

Before you buy

• Figure out what wind resources are available at your site. The U.S. Department of Energy publishes wind resource data, and you can hire a wind consultant to visit your site, take measurements, and give you a prediction of what to expect as far as wind energy production.
• Check with your electricity provider to obtain approval and agreements prior to installation.
• Check with your local governments, aviation board, and neighborhood associations, which sometimes object to residential wind turbines because of appearance, noise, or worries about property values. You may be asked for letters of support from your neighbors.
• Contact the National Audubon Society or local resources to determine if your site is in a bird migratory path. It’s unlikely that a single residential wind turbine, out of the migratory path, will cause trouble for birds, but California’s Altamont Pass Wind Resource Area is located in a migratory route and kills thousands of birds each year.
• Gather your energy bills for the past year or two and figure out exactly how much electricity your household uses annually.
• Currently, there is no certification process in the United States that covers turbine manufacture or performance. Consequently, residential wind turbines do not have to meet national or international standards of safety or reliability. Research your company thoroughly, and invest in the best equipment, design, and installation you can realistically afford.
• Be aware of your wind turbine system’s country of origin. Particularly if you buy from an individual owner or small company that imports systems, be sure that expert advice, maintenance, service, and parts will be readily available for years to come.