Wind

Although wind’s greatest potential lies in large regional installations, by investing in a small wind system for your home, farm, or business, you can reduce pollution, reduce future energy costs, and increase your own energy independence.

Deciding whether to purchase a wind system is complicated, and there are many factors to consider. With the right location, a wind energy system delivers cost-effective, clean, and reliable electricity.

Small wind energy systems can be applied for residential use in two ways:

Grid-Connected Systems use a small wind turbine in conjunction with electricity. Excess energy generated by the turbine allows you to send energy back into the power grid automatically as it’s generated. These systems are best suited for areas with high electric utility costs – and where local codes allow turbines:

Even individual homes can tap wind energy through small windmills and turbines.

Average annual wind speeds of at least 10 miles per hour
Utility-supplied electricity costs 10 to 15 cents per kilowatt-hour or more where you live and requirements for connecting renewable power to the grid are not expensive.
Local building codes and neighborhood covenants allow you to legally place a wind turbine on your property.

Stand-Alone Systems are wind installations that are not connected to a public utility. These systems are suited for homes, farms, or entire communities that are far from utility lines and would otherwise require expensive hook-ups to the grid.

Average annual wind speeds of at least 9 miles per hour
Grid connections are not available or can only be made through an expensive extension.
Supplementary systems or resources exist for dealing with the intermittent nature of wind and ensuring consistent power supply

Required Equipment

All wind systems consist of a wind turbine, a tower, wiring, and supporting components: controllers, inverters, and/or batteries.

Wind Turbines

Home wind turbines consist of a rotor, a generator mounted on a frame, and (usually) a tail.

The rotor captures the energy from the spinning blades to drive the generator. How much energy a turbine will produce depends on the diameter of the rotor, which determines how much wind can be captured by the turbine.
The frame is the strong central axis bar onto which the rotor, generator, and tail are attached.
The tail keeps the turbine facing into the wind.

The manufacturer will provide you with the expected annual energy output of the turbine as a function of annual average wind speed. The manufacturer will also provide information on the maximum wind speed in which the turbine is designed to operate safely. Most turbines have automatic speed-governing systems to keep the rotor from spinning out of control in very high winds. This information, along with your local wind speed distribution and your energy budget, is sufficient to allow you to specify turbine size.

Towers

Towers raise the turbine to a height where ground turbulence won’t interfere with its operation. “The higher the tower, the greater the power,” since wind speeds increase with altitude. A general rule of thumb is to install a wind turbine on a tower with the bottom of the rotor blades at least 30 feet above any obstacle that is within 300 feet of the tower.

Supplementary Components

Stand-alone systems require batteries and charge controllers to store excess power generated for use when the wind is calm.

Grid-connected systems require only an inverter that makes the turbine output electrically compatible with the utility grid. No batteries are needed.

Benefits

Wind energy systems provide a cushion against electricity price increases.
If you are building a home in a remote location, a small wind energy system can help you avoid the high costs of extending utility power lines to your site.
Wind energy is one of the lowest-priced renewable energy technologies available today, costing between 4 and 6 cents per kilowatt-hour, depending upon the wind resource and project financing of the particular project.

Considerations

Upfront costs are high. Wind energy is a long-term investment. The high costs of siting and installing a system require many years to pay back in terms of energy savings.
Wind is intermittent. Even at a good site, wind may not always blow when electricity is needed—and storing wind energy requires battery systems.
Noise and Aesthetics can be issues for some people. Though small systems are unobtrusive and quiet when compared with large turbine installations, there is some impact. These need to be evaluated based on the site and the system selected.

Getting Started

Invest in an Energy Efficiency Audit

This audit is a series of simple tests that will determine how energy efficient your building or home is. These tests should be conducted by a certified energy auditor and typically are conducted in a single day. The results of the audit will be able to tell where you are inefficiently using energy and what updates and improvements you can make.

Site Analysis

Wind speeds and steadiness can vary within the same area, so plan a site carefully. Be aware of the topography of your property – features such as small hills or gullies will affect the movement of the wind.

Consider the obstacles around you, but also plan for future obstructions—like trees and buildings—which could block the wind.

Also be aware that wind power works proportionally, meaning that the amount of power you get from your generator goes up exponentially as the wind speed increases. Small increases in wind speed produce increasingly greater returns on power.

Permitting

Wind turbines are more difficult to permit than other renewable power sources. Be sure to research potential legal and environmental obstacles in your area.

Some jurisdictions restrict the height of the structures permitted in residentially zoned areas, although variances are often obtainable. Neighbors might object to a turbine that blocks their view, or they might be concerned about noise.

If you plan to connect the wind generator to your local utility grid, find out its requirements for connecting and buying power before you move ahead.

Financing and Incentives

Grid-connected-system owners may be eligible to receive a small tax credit for the electricity they sell back to the utility. The National Energy Policy Act of 1992 and the 1978 Public Utilities Regulatory Policy Act (PURPA) are two programs that apply to small independent power producers.

Also, some states offer tax credits and some utilities offer rebates or other incentives that can offset the cost of purchasing and installing wind systems.

Finding a Contractor

Use the MCEC resource directory to identify companies who specialize in residential wind installations.