FREQUENTLY ASKED QUESTIONS

Are wind turbines noisy? Manufacturers of large, modern wind turbines expend considerable effort to ensure their machines are as quiet as possible. With years of experience installing machines in areas of high population concentration, especially in Europe, turbine manufacturers and engineers have developed quieter machine technologies.

One source of noise from a turbine is aerodynamic noise—i.e., the “swish” sound that the rotor blades make as they pass the tower of a wind turbine.Aerodynamic noise primarily occurs at the tip and the back edge of the rotor blade.The higher the rotational speed, themore noticeablethe sound.Aerodynamic noise has been cut dramatically over theyears due to better rotor blade design, particularly in the blade tips and back edges,and lower RPM machines.Rotor blade manufacturers take extreme care to ensure a smooth surface, which is important to reduce noise.

It is important that developers perform careful turbine siting, which in turn regulates the amount of noise produced. There are many techniques used to develop low-impact turbine locations: developers place turbines at a sufficient distance from homes, factor in the prevailing wind direction and the attenuation characteristics of the surrounding terrain, and understand the effects of other noise contributors such as yard noise and traffic sounds. As an effect of this turbine siting, an average residence in a well-designed project area should have turbines that produce sound levels similar to that ofa kitchen refrigerator. You are more likely to hear the wind over the sound made by the turbine.

Do wind turbines save energy? On average it takes less than six months for a wind turbine to recover all of the energy required to build and operate it. Wind turbines use energy from the moving air to generate electricity. Therefore, a modern wind turbine will displace the emissions of other electricity sources such as coal-fired power stations. For example, a 1.5 megawatt (MW) turbine will annually displace 3,000 tons of carbon dioxide generated by traditional electricity sources.

Are there enough wind resources around? Wind resources are plentiful, and North America has some of the windiest sites in the world. Plus, the wind will not run out.However, not all land is windy enough to support a large scale wind farm. Horizon Wind Energy seeks the windiest areas that have both access to transmission and electricity demand.

Can wind contribute significantly to electricity production? A far greater capacity of wind energy is produced each year compared to nuclear energy. Over 16,800 MW of wind power capacity was installed in the United States as of January 2008, which has generated over 51 billion kilowatt-hours of electricity annually. That is enough energy to power over five million average American households. Third-party experts are anticipating that the American market will continue its growth—increasing over threefold by 2015.

Is wind energy expensive? Depending on the robustness of the wind resource, wind is often the most competitive renewable energy technology in the world. In some markets, renewable energy can go head to head with conventional energy sources. While wind farm development is a capital-intensive industry, there are no fuel costs. Increases in the price of fossil fuels do not affect the wind industry.

Is wind energy safe? Wind energy leaves no harmful emissions or residues in the environment. Wind energy has a proven safety record.

Are wind turbines reliable? Yes. Modern wind turbines often have an availability factor above 98 percent (i.e., the turbines are ready to run on average during more than 98 percent of the hours of the year). This availability factor is similar to or can even be better than other electricity generating technology. Modern wind turbines require maintenance checks every six months and are built to very exacting industrial standards.

How much land is required to site wind turbines? On open, flat terrain, a utility-scale wind farm will require about 100 acres per MW of installed capacity. However, less than 5 percent, or 3 acres, of this area is actually occupied by turbines, access roads, and other equipment; 95 percent remains free for other compatible uses like farming and ranching. A wind farm located on a ridgeline in hilly terrain will require much less space, as little as two acres per MW.

Can wind turbines blend into the landscape? Wind turbines are obviously very visible, since they must be located in the windy, open terrain to be economical. Many factors can improve the visual impact of wind farms including a good design, the careful choice of paint color, and precise visualization studies before siting. As other well-designed structures, wind turbines can furnish a landscape with new architectural values.

How is the landscape affected after a wind turbine has been dismantled?
After the useful life of a wind farm has elapsed, foundations can be reused or removed completely. Because there is so much steel in a wind turbine tower, the scrap value of a turbine more than covers the costs of restoring a site to its initial state.

Do wind turbines bother wildlife? Deer and cattle habitually graze under wind turbines and sheep seek shelter around them. While birds tend to collide withstructures such as electrical power lines, guy wires, masts, and buildings, they are very rarely affected directly by wind turbines. Wind's overall impact on birds is low compared with other human-related sources of avian mortality, such as hunting, house cats, buildings, and automobiles. Horizon Wind Energy conducts extensive wildlife studies before, during, and after projects are built. We work with environmental groups, federal and state regulators, and other interested parties to ensure we are responsible environmental stewards.

Can wind turbines be placed anywhere? Landowner safety is our primary concern. Typically, wind turbines are placed a minimum of 1,000 feet away from houses,300 feet from non-participating landowner property lines, and 1,250 feet from non-participating landowner houses.

Terrain is also important. The energy content of the wind varies with the cube (i.e., the third power) of the wind speed. Twice as much wind yields eight times as much energy. Therefore, manufacturers and wind farm developers seek to site wind turbines in the windiest areas possible. The roughness of the terrain, its contours, and even the presence of buildings, trees, plants, and bushes affect the local wind speed and may create turbulence, which may decrease energy production and increase the wear and tear of the turbines.