The Environmental Effects & Energy Quantities of Wind Turbine Farms

One of the main causes of climate change is the growing output of greenhouse gases through fossil-fuel-generated electricity. The switch from fossil fuels to renewable wind energy can be a viable alternative, although it does have some obstacles that need to be overcome. Some of the concerns raised about wind energy include aesthetic and noise issues as well as destruction of environmentally sensitive areas and some species.

Energy Output

• According to the U.S. Department of Energy's Wind and Water Power Program, there are two categories of wind turbines: utility-scale turbines, ranging in size from 100 kilowatts to several megawatts, and larger turbines, which "are grouped together into wind farms, which provide bulk power to the electrical grid."

  Single small turbines, by contrast, are less than 100 kilowatts and typically are not part of the electricity grid. A recent Nature Conservancy article reported that in 2008, wind turbines generated enough energy to power 4.5 million U.S. homes for a year--a reduction of 44 million tons of carbon dioxide that would have been emitted into the atmosphere if the same amount of electricity had been generated using traditional fossil fuels.

Visual Impacts

• Wind turbines are very visible on a landscape. Many of the concerns about turbine appearance are related to the height and color of the blades, which can be addressed through research and better site planning. Another visual concern--the number of turbines in a given area and how they distract from the beauty of the landscape--is a more complicated issue that may be offset by finding a balance between the number and size of turbines needed to produce a given amount of wind energy in a specific location.

Noise Impacts

• The mechanical and aerodynamic features of wind turbines produce some noise during operation. Depending on the size of the turbine and the rotational speed of its blades, the amount of noise generated varies. As new turbine designs are developed for increased efficiency, some of the noise will be lessened. Proper siting also can help manage noise for nearby community residents and businesses.

Bird and Bat Deaths

• Birds and bats may collide with turbine blades, causing injury or death. While the actual impacts to bird and bat populations are debated among conservationists and wind-energy professionals, it is one of the most controversial issues surrounding wind-turbine technology. The actual impact varies depending on the size and type of wind farm as well and the migration routes and number of bird and bat species on or near the site.

Footprint

• Wind farms generally require more land area than fossil-fuel-generating power plants. While the exact amount needed for renewable energy technologies is not known, the Nature Conservancy estimates that, by the year 2030, the overall footprint for new development of renewable technologies in the United Sates could cover an area larger than the state of Minnesota. One of the main concerns is that as the landscape is altered by wind farms, sensitive grasslands and other habitats and species may be damaged or destroyed in the process.