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SACE | Southern Alliance for Clean Energy

Learn About Environmental Impacts of Wind Energy

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Wind power is a clean, locally available energy resource that has abundant potential in the Southeast. All energy generation sources produce some kind of environmental footprint, even sources that are predominantly renewable. Dirty and dangerous sources of energy, such as coal and nuclear, require destructive mining practices in order to obtain the fuel required to generate electricity. A wind turbine is not dependent on mining since wind is the fuel source that produces electricity. Wind energy does not create harmful pollutants such as NOx, SOx, CO2, and particulate matter or radioactive waste as a result of its electrical generation. Nor does wind energy require massive amounts of water in order to generate electricity in the way traditional generation sources, such as coal and nuclear, do. The generation of electricity from wind energy is renewable and clean; however, wind farms must be sited in locations that minimize their overall environmental footprint.

Climate Change Benefits
At present, the Southeast is overly dependent on fossil fuels that pose serious risks to air and water quality and contribute to global warming pollution. The development of wind power can help displace fossil fuels and ultimately help reduce global warming pollution in our region, which reduces the negative impacts of climate change.

Water Saving Benefits
Wind energy reduces water consumption in the electric power sector — the largest water user in our region. Both nuclear and fossil-based electricity generation consume massive amounts of water. Wind power reduces our reliance on increasingly vital and scarce freshwater resources. The U.S. Department of Energy’s Wind Powering America Program estimates, for example, that 1000 MW of wind power development in Georgia would bring annual water savings of 1,628 million gallons.

MINIMIZING IMPACTS OF WIND TURBINES

Studying all potential environmental impacts of a wind project.

Pre-construction studies of birds, bats, ecological and biological impacts are important before wind turbines are built. Sometimes, these studies are required in advance through a state-level permitting process. This permitting process must be fair and balanced to ensure that a developer undertakes studies with due diligence illustrating the potential impacts of a wind project. A permitting agency may require a developer to create strategies to minimize or mitigate these impacts. If a developer is able to present a strategy to minimize these impacts, the permitting agency will often require post-construction studies to verify that no significant impacts to biological and ecological systems are occurring. Southern Alliance for Clean Energy understands that the impacts of a wind project are site specific and always encourages developers to study the impacts of a wind project in a transparent process. We further believe that if a wind energy project illustrates no significant impacts, then a project should be permitted to be built in a timely fashion.

Onshore Wind

Understanding Onshore Wind Energy and Bird Impacts

During the 1980′s in California, where wind energy projects were first constructed in the United States, a project was constructed at Altamont Pass. The project consisted of approximately 4,900 wind turbines totaling 576 MW. According to reports from the California Energy Commission, the wind farm killed a large number of raptors and birds. In 1994, a consortium of environmental groups, utilities, government officials and wind developers formed the National Wind Coordinating Committee to focus on wind/avian impacts. According to a Government Accountability Office report, several factors contributed to the impacts on avian species at Altamont Pass.

  1. Number of turbines on site. At that time, older turbines were smaller in size and therefore more were required to produce electricity. In contrast, it would take appoximately 250 modern wind turbines to equal the same capacity as the 4,900 older turbines.
  2. Technology. Older turbines were placed on shorter towers, closer to the ground, and the towers were made of lattice framework which encouraged birds to perch on them. Smaller turbines have blades that turn at much higher rate. Modern turbines now are placed on higher towers that are constructed of tubular steel, and have larger blades that revolve at much slower RPMs.
  3. Project siting. Perhaps the most important issue for the industry to discover, was that the project was located in prime habitat for prey of the California raptors. The unique geology of the Altamont Pass location allowed raptors to sit high on the ridge and dive into the valley for prey.

These findings encouraged the NWCC to spend years defining proper pre-construction siting techniques, mitigation strategies, and post-construction siting techniques that allow wind turbines to be responsibly sited to avoid future significant impacts. Today, with modern turbines and responsible siting practices, many studies have shown that modern wind turbines kill only between 3-5 birds/turbine/year. This number is far less than most other man made structures, and even less than your average house cat.

Understanding Onshore Wind Energy and Bat Impacts

As the wind industry spread across the United States in the late 90′s and early 2000′s, it discovered a new local impact that needed to be accounted for, bat fatalities. In 2003, the Bats and Wind Energy Cooperative (BWEC) was formed through a partnership by Bat Conservation International, U.S. Fish and Wildlife Service, the American Wind Energy Association, and the National Renewable Energy Laboratory of the U.S Department of Energy in response to findings of higher bat fatalities at these facilities. Through BWEC, it was discovered that bat impacts typically occur during late-August and early-September, which is a migration season for certain species of bats. The impacts typically occur during low wind speed times, which enable the bats to hover around the tips of the wind blade. There are currently mitigation strategies being implemented at wind farms to study the potential for raising the cut-in speed of the wind turbine to ensure that the blades do not turn until wind speeds are higher. This strategy was shown to reduce bat fatalities at the locations where it was implemented. Research is also being conducted to create a bat deterrent. Bat deterrent is using an artificial device to keep the bats away from the wind turbines, sometimes nicknamed the magic whistle. This technology is still being researched and experimented with.

Impacts of Wind Farms on Coastal Ecology

Our region’s coastal waters are home to special plants and animals, some of which are endangered and many others that hold a special place in our overall coastal ecology. Wildlife habitat can be affected by transmission access during wind farm construction or maintenance. Marine or bird species may have habitats or migratory paths that could intersect with possible wind farm sites. Wind farm developers are required by federal law to identify all potentially impacted species and determine ways to make the most environmentally sound decisions prior to getting approval to site an offshore wind farm. Special laws exist for state waters too. Special consideration is required for migratory bird corridors. Collision risk and possible habitat loss are required to be incorporated into future environmental assessments.

Offshore Wind

Offshore wind farms bring many environmental benefits, including cleaner air and cleaner water. Yet, our offshore ocean environment is home to a diverse group of biological species that must be appropriately studied when siting wind projects to ensure no significant adverse impacts occur. Because offshore wind farms are new to the United States, there is not a wealth of information available yet about the environmental impacts for our region. However, much can be learned from the findings in Europe where offshore wind farms have been in operation for over 20 years. For example, the Danish studies found that most birds seem to fly around offshore wind turbines rather than into them, and many species avoid the areas altogether. birdsandradar.gif Special consideration is required for migratory bird corridors. Collision risk and possible habitat loss are required to be incorporated into future environmental assessments. Also, for our region and the entire Atlantic coastline, the migration of the North Atlantic right whale needs to be factored into wind farm siting decisions. The endangered right whales pass through waters off the Florida, Georgia and South Carolina coast when they are calving in the fall and winter and travel along the Atlantic seaboard to the north Atlantic region for the remainder of the year. Wind developers in our region must follow a construction schedule that does not overlap the calving season between December and March.