1. What is Wind Power?
Wind power is the conversion of wind energy using wind turbines, which transforms the kinetic energy into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.
A wind turbine produces electricity when wind turns the blades, which spin a shaft, which connects to a generator, which in turn generates electricity. Wind turbines can be used to produce electricity for a single home or building, or they can be connected to an electricity grid for more widespread electricity distribution. Wind turbines are mounted on a tower to capture faster and less turbulent wind. For more information on wind energy, visit the U.S. Department of Wind & Hydropower Technologies Program, or for a more detailed history of wind energy, click here.
A wind turbine includes:
Wind turbines come in all shapes and sizes with different applications for each size. Generally, wind turbines are used for the following applications, based on their size:
The chart below shows a variety of turbine sizes and the amount of electricity they are each capable of generating. (source: American Wind Energy Association – Power of Wind)
3. What is Utah’s Wind Energy Resource Potential?
Utah has the technical potential to contribute nearly 2500 Megawatts of wind – this excludes sensitive lands, national parks, and areas unsuited for wind development (i.e. the top of Mt. Timpanogos). This amount of wind would provide enough energy for over 660,000 average Utah homes and yield a net economic benefit of approximately $2.7 billion and over 1,110 long term jobs.i These estimates are based on data from the National Renewable Energy Laboratory, the Utah State Energy Program, Utah Anemometer Data, Utah State University Jon M. Huntsman School of Business, and wind developers. Learn more about Utah’s wind potential at the Governor’s Renewable Energy Zones Task Force.
If you think you have a good wind resource that is not identified on these maps:
Figure 4 - WATER CONSUMPTION—Electricity Generation
Source: American Wind Energy Association
The following are the most significant challenges wind energy development faces today:
a. Does wind energy take up a lot of land?
One square mile can accommodate 10-20 MW of wind, with the majority of the land left for its original use (farming, ranching, etc.). Wind farms are spaced over a large geographic area, but their actual "footprint" covers only a small portion of the land and do not interfere with crop production or livestock grazing. The black squares on the map below (see Figure 5) represent the total area taken up for wind developments in each state, should the country achieve 20% wind by 2030. The white square in the middle of the black square represents the total amount of land taken out of commission.
b. How much electricity does a wind turbine generate?
The output of a wind turbine depends on the turbine's size and the wind's speed through the rotor. Wind turbines now being manufactured have power ratings ranging from 250 watts to 3 megawatts (MW). The speed and regularity of the wind determines the “capacity factor” or the percentage of time the turbine will be running. Small differences in wind speed can mean a large difference in available energy and in electricity produced, leading to a large difference in the cost of the electricity generated. (Source: http://www.powerofwind.com/node/7)
A general equation for determining the output of a wind turbine is as follows:
Megawatt hours/year (MWh/yr) =
Rated Turbine Capacity (MW) x Capacity factor (%) x Number of hours in a Year (8760 hrs)
Example: A 2 MW turbine with a capacity factor of 25% would yield approximately 4380 MWh/yr.
c. How does wind energy contribute to our electricity needs?
Domestic wind power has been installed across 35 states and delivers nearly 1% of the electricity consumed in the nation. In 2007, U.S. cumulative wind energy capacity reached 16,818 MW, which is power equivalent to the demand of 4.5 million U.S. homes. Wind power contributed more than 30% of the new U.S. generation capacity, and President Bush has suggested that wind has the potential to supply up to 20% of the nation's electricity.ii
According to the U.S. Department of Energy’s “20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply” (2008), the Nation possesses affordable wind energy resources far in excess of those needed to enable a 20% wind energy scenario.iii The report also finds that the 20% wind scenario could:
d. How much does wind energy cost?
Wind power costs are competitive with energy generated by conventional power plants, but the up-front costs of wind energy are often more expensive than that of some traditional power technologies. However, wind receives tax credits and other economic benefits, which make it a viable choice for renewable energy generation. (Source: AWEA Power of Wind)
For information on small wind installations visit our Wind How To for Homeowners.
All energy resources (fossil, renewable, and alternative) receive subsidies from the federal and state governments in one form or another. These subsidies combined with rules and regulations influence the energy market significantly, effecting prices and costs. Energy does not operate in a “free market”, but rather a strictly regulated and heavily subsidized market. For more information on energy subsidies, read these reports from the U.S. Energy Information Association:
With today’s rising coal and gas prices, new wind plants compete favorably against any new electricity generation source. In fact, when the Colorado Public Service Commission issued a ruling on the 161-MW wind project in Lamar, Colorado, the commission determined that wind energy provided the lowest cost of any generation resource submitted to a solicitation bid by Xcel Energy. The commission also noted that unlike the other generation resources considered, the Lamar project avoided a future risk of increased fuel prices.vi
e. Does wind energy need backup for times when the wind stops blowing?
Because of the electric grid’s inherent design, there is no need to back up every megawatt of wind energy with the equivalent amount of fossil fuel power. The electric grid is designed to have more generation sources than are needed at any one time because no power plant is 100 percent reliable. Utilities are accustomed to balancing the numerous generation sources to meet the demand, and wind power has been successfully integrated into power grids across the world. For more information on wind integration, visit the Utility Wind Integration Group.
f. Do wind turbines make a lot of noise?
An operating modern wind farm at a distance of 750 to 1,000 feet is no louder than a kitchen refrigerator. The sound turbines produce is similar to a light whooshing or swishing sound and is much quieter than other types of modern-day equipment. Even in rural or low-density areas (where there is little additional sound to mask that of the turbines) the sound of the blowing wind is often louder.
Model wind zoning ordinances a maximum of 60 dBA, as measured at the closest neighboring inhabited dwelling for small wind; for commercial-wind, the ordinance should adhere to the manufacturers rated dBA as measured at the property line or as measured at the nearest neighboring inhabitable building. For more information on model wind zoning, click here.
g. Does wind power harm birds and wildlife?
Wind energy development’s overall impact on birds is extremely low compared with other human-related activities. 1 in every 10,000 avian deaths can be attributed to wind power; the most common culprits are housecats, glass windows, and cars. Despite the minimal impact wind development has on birds and bats in most areas, the industry takes potential impacts seriously. Avian studies are routinely conducted at wind sites before projects are proposed. These pre-construction wildlife surveys are common practice throughout the industry.
Additionally, the Audubon Society “strongly supports properly-sited wind power as a clean alternative energy source that reduces the threat of global warming. Wind power facilities should be planned, sited and operated to minimize negative impacts on bird and wildlife populations.” For additional information on wind and wildlife, download the following fact sheets available from the American Wind Energy Association:
iNational Renewable Energy Laboratory, Wind Powering America Program. Utah Economic Impacts from the 20% Wind Vision (2,449 MW new Utah wind development). U.S. Department of Energy, Energy Efficiency and Renewable Energy Technologies Program. 2007.
iiWind Energy Could Produce 20 Percent of U.S. Electricity By 2030: DOE Report Analyzes U.S. Wind Resources, Technology Requirements, and Manufacturing, Siting and Transmission Hurdles to Increasing the Use of Clean and Sustainable Wind Power. Department of Energy Press Release. May 2008. URL: http://www.energy.gov/news/6253.htm
iii20% Wind Energy by 2030: Increasing Wind Energy’s Contribution to U.S. Electricity Supply. Department of Energy. 2008. URL: http://www.20percentwind.org/default.aspx and
vSee reference i.
viColorado PUC Lamar wind decision of 2001. Interwest Energy Alliance. http://www.interwest.org/wiki/index.php?title=Colorado_PUC_Lamar_wind_decision_of_2001