Residential Wind Turbines: Basic Facts for Homeowners

Between 2004 and 2008, residential wind power in the United States increased at an annual rate of 32 percent. That figure has more than doubled over the past two years and now exceeds 75 percent. Homeowners considering a wind system have no trouble finding someone who wants to sell them the equipment and provide the labor for installation. What they may find difficult, however, is getting hard, fast facts on which to base their decision.

In calculating the total cost of buying and owning a wind turbine, consider the following:

• A residential wind turbine will only be cost effective if the local rate for electricity per kilowatt hour is 10 cents or more. (The current national average price is 12 cents.)
• The average American home consumes 9,400 to 10,000 kWh annually. A turbine capable of producing 5 to 15 kilowatts will be needed to make a real impact on the home's electrical bills.
• Turbines mounted on towers of 85 to 150 feet have the potential to lower home energy costs from 50-90 percent.
• Smaller, roof-mounted turbines can rarely improve home electrical costs by more than 10 percent.
• A steady, annual wind speed of 10 to 12 mph is the acceptable minimum for efficient residential turbine operation.
• The recommended physical space for a residential turbine is one acre, with the unit placed 250 feet from adjacent structures to minimize turbulence.
• Under the Public Utility Regulatory Policies Act of 1978, electric companies are required to allow interconnection with small wind systems with a capacity of 80 MW and less and to purchase excess energy produced by those systems.
• The Emergency Economic Stabilization Act of 2008 created a federal investment tax credit for residential, farm, and small business turbines of 100 kW or less. As amended by the American Recovery and Reinvestment Act of 2009, the credit is uncapped and is worth 30 percent of the expense of a turbine's installation. The credit will be valid through December 31, 2016.
• Professionally installed residential wind turbines cost $22,000 to $45,000+ depending on size and capacity.
• Realistically, the length of time necessary to recoup the total investment will be 15 to 20 years.
• Post-installation maintenance costs average 2.5 to 2 percent of the system's original cost or roughly 0.01 cents per kWh.
• After a turbine has been in operation ten years or more, the rotor blades, gearbox, and bearings will normally need to be replaced. These costs will run to approximately 15 to 20 percent of the turbine's original cost.

No site will have optimal wind year round, and it is extremely difficult to find a turbulence-free area in a residential setting. On the low-end of expected performance, (a 10 percent power offset for a roof-mounted turbine), electrical savings per year at the national average would be $120. In absolutely perfect conditions, a 10 kilowatt turbine could generate 10,000 kWh a year. There are two obvious conclusions to draw from this information:

• A professional wind assessment of the site must be conducted to determine wind speed, to make accurate recommendations for the necessary equipment, to pinpoint optimal turbine placement, and to accurately estimate energy savings.
• In a residential setting, a turbine should be a component of a broader program of energy conservation. Homeowners who first conduct an energy audit to understand exactly how much electricity they are using and to identify sources of waste, will derive the maximum benefit from adding a wind turbine.

Installing a residential wind turbine is a major home improvement project. The unit can represent substantial energy savings and will increase the value of the home. It will not, however, instantly pay for itself and not all sites are right for the incorporation of wind energy. Before you talk to a turbine company, learn the basics of home wind energy to protect yourself from hard-sell tactics and to maximize your long-term investment in clean, renewable energy.

This guest post by Rana Williamson of HowToSaveElectricity.net, which offers information for the homeowner on how to save electricity using simple energy conservation tips and supplementing energy needs using solar and residential wind power.