Wind Energy FAQs for Consumers

If you are a homeowner considering using a wind turbine to power your home, there are a number of considerations. By investing in a small wind system, you can reduce pollution and reduce your exposure to future fuel shortages and price increases. Deciding whether to purchase a wind system, however, is complicated; there are many factors to consider. But if you have the right set of circumstances, a well-designed wind energy system can provide you with many years of cost-effective, clean, and reliable electricity.

What are the benefits to homeowners from using wind turbines?

Wind energy systems provide a cushion against electricity price increases. Wind energy systems reduce U.S. dependence on fossil fuels, and they don't emit greenhouse gases. 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.

Although wind energy systems involve a significant initial investment, they can be competitive with conventional energy sources when you account for a lifetime of reduced or altogether avoided utility costs. They length of the payback period — the time before the savings resulting from your system equal the system cost — depends on the system you choose, the wind resource in your site, electric utility rates in you're area, and how you use your wind system.

Is wind power practical for me?

Small wind energy systems can be used in connection with an electricity transmission and distribution system (called grid-connected systems), or in stand-alone applications that are not connected to the utility grid. A grid-connected wind turbine can reduce your consumption of utility-supplied electricity for lighting, appliances, and electric heat. If the turbine cannot deliver the amount of energy you need, the utility makes up the difference. When the wind system produces more electricity than the household requires, the excess can be sold to the utility. With the interconnections available today, switching takes place automatically. Stand-alone wind energy systems can be appropriate for homes, farms, or even entire communities (a co-housing project, for example) that are far from the nearest utility lines. Either type of system can be practical if the following conditions exist.

Conditions for stand-alone systems

• You live in an area with average annual wind speeds of at least 4.0 meters per second (9 miles per hour)
• A grid connection is not available or can only be made through an expensive extension. The cost of running a power line to a remote site to connect with the utility grid can be prohibitive, ranging from $15,000 to more than $50,000 per mile, depending on terrain.
• You have an interest in gaining energy independence from the utility
• You would like to reduce the environmental impact of electricity production
• You acknowledge the intermittent nature of wind power and have a strategy for using intermittent resources to meet your power needs

Conditions for grid-connected systems

• You live in an area with average annual wind speeds of at least 4.5 meters per second (10 miles per hour).
• Utility-supplied electricity is expensive in your area (about 10 to 15 cents per kilowatt-hour).
• The utility's requirements for connecting your system to its grid are not prohibitively expensive.
• Local building codes or covenants allow you to legally erect a wind turbine on your property.
• You are comfortable with long-term investments.

Is my site right?

To get a general idea if your region has good wind resources, look at the Wind Powering America Wind Resources page, which has state wind maps. The maps will show you if wind speeds in your area are strong enough to further investigate the wind resource. Of course, the maps are just a starting point — the actual wind resource on your site will vary depending on topography and structure interference. And a localized site with good winds, such as a ridgetop, may not show up on the maps.

Another source for wind data is the National Climatic Data Center, which collects data for selected sites and makes area wind data summaries available for purchase.

You will need site-specific data to determine the wind resource at your exact location. If you do not have on-site data and want to obtain a clearer, more predictable picture of your wind resource, you may wish to measure wind speeds at your location for a year. You can do this with a recording anemometer, which generally costs $500 to $1500. The most accurate readings are taken at "hub height" (i.e., the elevation at the top of the wind turbine tower). This requires placing the anemometer high enough to avoid turbulence created by trees, buildings, and other obstructions. The standard wind sensor height used to obtain data for the DOE maps is 10 meters (33 feet).

You can have varied wind resources within the same property. If you live in complex terrain, take care in selecting the installation site. If you site your wind turbine on the top or on the windy side of a hill, for example, you will have more access to prevailing wind than in a gully or on the leeward (sheltered) side of a hill on the same property. Consider existing obstacles and plan for future obstructions, including trees and building, which could block the wind. Also realize the power in the wind is proportional to its speed (velocity) cubed (v�). This means that the amount of power you get from your generator goes up exponentially as the wind speed increases. For example, if your site has an annual average wind speed of about 5.6 meters per second (12.6 miles per hour), it has twice the energy available as a site with a 4.5 meter per second (10 mile per hour) average (12.6/10³).

What about legal, environmental and economic issues?

In addition to reviewing your site and particular situation and goals, you should also

• research potential legal and environmental obstacles
• obtain cost and performance information from manufacturers
• perform a complete economic analysis that accounts for a multitude of factors
• understand the basics of a small wind system, and
• review possibilities for combining your system with other energy sources, backups, and energy efficiency improvements.

Establish an energy budget to help define the size of turbine that will be needed. Since energy efficiency is usually less expensive than energy production, making your house more energy efficient first will likely result in being able to spend less money since you may need a smaller wind turbine to meet your needs.

Potential Legal and Environmental Obstacles

Before you invest any time and money, research potential legal and environmental obstacles to installing a wind system. Some jurisdictions, for example, restrict the height of the structures permitted in residentially zoned areas, although variances are often obtainable. Your neighbors might object to a wind machine that blocks their view, or they might be concerned about noise. Consider obstacles that might block the wind in the future (large planned developments or saplings, for example). If you plan to connect the wind generator to your local utility company's grid, find out its requirements for interconnections and buying electricity from small independent power producers.

Pricing a System

When you are confident that you can install a wind machine legally and without alienating your neighbors, you can begin pricing systems and components.

Approach buying a wind system as you would any major purchase. Obtain and review the product literature from several manufacturers. Lists of manufacturers are available from the American Wind Energy Association; however, not all small turbine manufacturers are members of AWEA. Manufacturer information can also be found at times in the periodicals listed below. Once you have narrowed the field, research a few companies to be sure they are recognized wind energy businesses and that parts and service will be available when you need them. Also, find out how long the warranty lasts and what it includes.

Ask for references of customers with installations similar to the one you are considering. Ask system owners about performance, reliability, and maintenance and repair requirements, and whether the system is meeting their expectations.

The Economics of Wind Power for Home Use

A residential wind energy system can be a good long-term investment. However, because circumstances such as electricity rates and interest rates vary, you need to decide whether purchasing a wind system is a smart financial move for you. Be sure you or your financial adviser conduct a thorough analysis before you buy a wind energy system.

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. PURPA also requires that the utility sell you power when you need it. Be sure you check with your local utility or state energy office before you assume any buy-back rate. Some Midwestern rates are very low (less than $.02/kWh), but some states have state-supported buy-back rates that encourage renewable energy generation. In addition, some states have "net billing," where utilities purchase excess electricity for the same rate at which they sell it.

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. Visit the DSIRE web site, which contains a database of financial incentives for wind energy. Check with your state's department of revenue, your local utility, public utility commission, or your local energy office for information.

Credits: U.S. Department of Energy