Small Wind Energy Systems (Wind Turbines) contain electric generators that convert the power of the wind into clean, emissions-free power for individual homes, farms, and businesses. In most areas of the country small turbines may be suitable for owners with as little as one acre of land , and some designs may even be suitable for roof-mounting in certain urban environments.
Wind Energy Explained by DOE
Tax Credits Explained
Picture of a Horizontal Axis Wind Turbine
Small Wind Turbine Installed at a Retail Store
Pole Mounted Wind Turbine
Vertical Axis Wind Turbine
Wind Turbines are a Proven Technology.
- Wind power has been used for more than two thousand years.
In the U.S., small wind turbines have been used to produce electricity since the 1930s, and many systems currently in use date from the 1980s.
More than 10,000 small wind turbine systems were installed in the U.S. in 2010 alone.
Wind Turbines are Mechanical Systems.
Wind turbines convert the kinetic energy in the wind (the energy the wind has due to its motion) into mechanical energy—the wind turns the blades of the wind turbine, and the blades turn a shaft inside the turbine. An electric generator inside the wind turbine then converts this mechanical energy into electrical energy.
Wind Turbines are Highly Durable, are Generally Warranted for 10 Years, and Can Last for Over 20 Years.
Wind energy systems typically last 25+ years, and require only occasional maintenance.
The National Renewable Energy Laboratory, in conjunction with the Small Wind Certification Council, has begun to test and certify small wind turbines. The wind turbines are tested to meet standards in each of the following areas:
Noise emissions, to determine sound levels at different wind speeds;
Duration, to test wind turbine operation over long periods of time;
Power performance, to determine power generation performance at different wind speeds;
Power quality, to determine consistency of power output; and
Safety and function testing, to make sure that turbines conform to design standards.
Wind Systems That are Tied to the Grid Do Not Require Batteries to Store Power.
Wind turbines only produce electricity when there is sufficient wind to turn the blades of the turbine. Wind systems are thus usually operated in conjunction with electricity supplied from the grid—the grid supplied electricity serves as a backup to ensure constant electric power when there is no wind.
In certain remote locations that are not grid-accessible, batteries can be used to store electricity for use when there isn't enough wind to generate electricity.
Small Wind Systems Can Eliminate Most of, If Not All of, an Owner's Electricity Bill.
A typical home would require one or more small wind turbines with a 5 kilowatt (kW) generating capacity to meet all of its electricity needs. Individual small wind turbines can produce from 1.5 kW to 10 kW of electricity.
In states with net-metering legislation, grid-tied wind turbines can be used to credit your electricity account. In those states, when a grid-tied wind turbine produces more electricity than is needed to power your home or business, it feeds the extra electricity into the grid, spinning your meter backward and crediting your electricity account. When you need more electricity than the wind turbine is producing, you make up the difference with grid-supplied electricity, and your meter will spin forward, debiting your electricity account. You will only have to pay your electric utility if you take more electricity from the grid than your wind turbine put into the grid. If your wind turbine produces more electricity than you need, your utility company will actually send you
a check for the net electricity you put into the grid, rather than the other way around.
Innovations in Design Have Resulted in Turbines That Have Attractive Aesthetics and Operate with Low Noise.
Some small wind turbines produce as little as 35 decibels (dB) of sound when heard from a distance of only ten feet away. By comparison, a whisper-quiet library is equivalent to 30 dB.
Small Wind Turbines are Most Suitable for Consumers Who Have High Electricity Consumption and/or Expensive Electricity Rates, Have Sufficient Wind, and Are Permitted by Local Codes to Site a Turbine on Their Properties..
The price of wind systems on a per-watt basis depends on their size and output--they tend to become less expensive as the size of the system increases. That is why wind systems are preferable for owners who consume large amounts of electricity, and who can properly site a turbine.
Some smaller wind turbines (1,500 watts) can be purchased for approximately $5.50/watt, and are suitable for roof-mounting. That per-watt price is comparable to the cost of solar photovoltaic (PV) systems, and these smaller wind turbines may be suitable for owners who, because of shading or for other reasons, cannot install a PV system.
It is Best to Install Wind Turbines in Areas That Consistently Have Wind Speeds of 7-12 mph (the higher the better).
- Rural or suburban locations
: Grid-tied systems should be sited in areas with average annual wind speeds of at least 10 mph and low wind turbulence, though many manufacturers recommend 12 mph winds. Some small wind turbines, however, have "cut-in" (starting) winds speeds as low as 2 mph!
- Coastal regions
: Coastal sites are generally favorable because winds tend to be stronger and more consistent as they come off the water.
Land with unobstructed access to winds
: Flat, open land with few trees or tall buildings to block the wind is also well suited for wind systems.
Be sure to measure!
Wherever your property is located it is essential that you determine first whether there is enough wind to justify an investment in a wind turbine. Look under the caption "Additional Resources," below for suggestions on how to find out whether there is enough wind at the site that you hope to use.