What Does Wind Do To The Environment?
Wind energy is renewable energy generated through the harnessing of wind power via wind turbines. Wind is created by temperature differences in the atmosphere which lead to moving air currents. Wind turbines convert the kinetic energy of the wind into mechanical energy, which then becomes electrical energy through a generator (Wind power: your questions answered, https://friendsoftheearth.uk/sites/default/files/downloads/wind_power_your_questions.pdf).
Wind power plays a crucial role in renewable energy production worldwide. It is one of the most widely used and rapidly growing renewable energy sources. Wind energy offers a sustainable alternative to fossil fuels, produces no greenhouse gas emissions during operation, and helps address climate change. The growth of wind power is essential for transitioning our energy systems away from coal, oil and natural gas towards low carbon solutions (The Role of Wind Power in Achieving Sustainable Development Goals, https://energy5.com/the-role-of-wind-power-in-achieving-sustainable-development-goals/).
Wind Energy Production
Wind turbines convert kinetic energy from the wind into mechanical power. A wind turbine has blades that spin when the wind blows, turning a rotor connected to a generator to produce electricity. The generator uses magnetic fields to convert the rotational energy into electrical energy. Most turbines have a horizontal axis orientation, with the blades facing into the wind. Larger blades can capture more wind energy and generate more electricity. Utility-scale wind turbines range from 100 feet to over 500 feet tall.
Wind flows over the blades, creating lift and causing them to turn. The blades are connected to a drive shaft that turns a generator to produce electricity. The electricity is sent through transmission and distribution lines to homes, businesses, schools, and other consumers. The amount of electricity generated depends on the turbine size and wind speed. One turbine can provide enough electricity for 600 homes on average. Wind farms consist of many wind turbines and generate bulk electrical power.
According to energy.gov, wind power capacity has expanded significantly to provide 7% of total U.S. electricity generation. Wind energy production continues to grow as larger turbines are developed and more wind farms are built across the country.
Environmental Benefits
One of the most significant environmental benefits of wind energy is the reduction in fossil fuel use and greenhouse gas emissions. According to a 2013 study published in Applied Energy, “Quantifying the health and environmental benefits of wind power”, wind energy was found to reduce SO2, NOx, and CO2 emissions by amounts comparable to taking 22 million cars off the road (McCubbin). This is because wind turbines produce electricity without emitting any toxic pollutants or greenhouse gases. Widescale use of wind power can help countries meet their climate goals under the Paris Agreement and reduce air pollution-related health impacts.
The reduction in air pollution from expanded wind power generation is substantial. Researchers from the University of California, Santa Barbara estimate that “the environmental benefits of wind power are roughly equal to the cost required to spur the production of wind energy” (Cullen). Wind helps avoid the negative externalities of fossil fuel energy production, including the social cost of carbon emissions. One major 2013 study found that just the carbon dioxide emissions avoided thanks to wind energy in the Upper Midwestern U.S. were worth $28-$54/MWh (McCubbin).
Land Use
Wind farms require large areas of land to capture wind energy effectively. According to the National Renewable Energy Laboratory (NREL), the land use footprint for a wind farm ranges from 30 to 141 acres per megawatt of installed capacity, with an average of about 50 acres per megawatt (https://www.ourworldofenergy.com/vignettes.php?type=wind-power&id=9). This means a 50 MW wind farm would require around 2,500 acres of land.
However, wind turbines use only a small portion of this land directly. Access roads, substations, and other infrastructure take up some space, but much of the land can still be used for other purposes like farming or grazing. Studies show that only 1-5% of wind farm land is occupied by turbines and infrastructure (https://www.mdpi.com/2073-445X/10/5/442). The remaining 95-99% can be used for dual purposes.
Siting wind farms on agricultural lands is often done to provide farmers with a supplemental income source while still allowing agriculture activities to continue. However, inappropriate siting can disrupt farming operations and impact soil quality. Proper zoning, setbacks from buildings, and community agreements help minimize land use conflicts for wind projects.
Wildlife Impacts
Wind turbines can have negative impacts on wildlife, especially birds and bats. One of the biggest concerns is collisions between birds/bats and turbine blades. Birds face the most risk because they regularly fly at the same height as wind turbine blades (Park 2013). One study estimated that 140,000 to 328,000 birds are killed annually by collisions with wind turbines in the U.S. (Park 2013). Migratory birds face the most risk because their flight paths overlap with wind farm sites. Bats are also susceptible to barotrauma caused by sharp air pressure reductions near moving turbine blades, even if they don’t directly collide with the blades (Park 2013). Some studies suggest bat mortality rates may be even higher than birds at wind facilities (Park 2013). Turbine lighting and guy wires supporting turbines have also been implicated in increased collisions. Careful site selection, improved turbine design, and curtailment during high risk periods may help minimize wildlife impacts.
(Park, K.J., 2013. The case of micro-turbines and wildlife conservation: The conflict between international wildlife conservation efforts and human use of week technology. Journal of Wildlife Policy. December 2013. 10(4): 345-365. https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/jpe.12005)
Noise Pollution
Sound emitted from wind turbines is a major concern regarding their environmental impact. Wind turbines generate noise from mechanical and aerodynamic sources. The main mechanical noise comes from the gearbox and generator, while aerodynamic noise is created by the blades passing through the air (1).
The noise generated by wind turbines propagates over long distances. Wind turbine noise is generally broadband in nature, consisting of swishing and thumping sounds. The noise level depends on factors like turbine design, wind speed, and distance from the turbine (2).
Trailing edge noise from the rotor blades is a dominant source of wind turbine noise. Researchers have looked at owl wing designs to help reduce this trailing edge noise from wind turbines and aircraft. The serrated edges of owl wings help break up turbulent airflow and reduce noise. This bio-inspired design can be used to make quieter wind turbine blades (3).
Overall, wind turbine noise can be an annoyance and disturbance to nearby residents. Proper siting, setbacks, and noise-reducing blade designs can help mitigate noise pollution from wind turbines.
Sources:
(1) https://www.pagerpower.com/news/wind-turbine-noise-pollution/
(2) https://phys.org/news/2022-01-owl-wing-aircraft-turbine-noise.html
Aesthetic Impacts
Wind turbines can have a visual impact on landscapes, especially in rural areas. The modern wind turbine is a very large structure, often reaching over 400 feet tall. Having numerous wind turbines concentrated together in wind farms can significantly alter the look of an open landscape.
According to a 2017 study, “Mitigating the wind farm aesthetic impacts can be addressed most efficiently during the project’s planning stages.” The study recommends proper sitting and design to help minimize the visual impact of wind turbines on landscapes (https://www.diva-portal.org/smash/get/diva2:1117440/FULLTEXT01.pdf).
Strategic placement, like avoiding sight lines from major roads and residential areas, can help reduce the visual dominance of wind turbines. Painting the turbines in neutral colors to blend with the landscape also helps diminish the visual presence. Proper lighting is also important to limit light pollution at night.
Other Environmental Effects
In addition to impacts on wildlife, wind turbines can also affect other aspects of the environment like soil and water. Construction of wind farms disturbs the soil and can lead to erosion if not properly managed. According to the Department of Energy, erosion control plans and stormwater pollution prevention plans are required during construction to minimize soil runoff and impacts to surface water quality (source).
The operation of wind turbines does not require water for cooling or other purposes, unlike some other energy sources. However, the concrete foundations of wind turbines can potentially leach minerals and chemicals into the soil and nearby water bodies. Proper foundation design and siting is important to prevent groundwater contamination (source).
Overall, while wind power does not emit air pollution or greenhouse gases, wind farms can still impact soils, surface water, and groundwater if not properly sited, constructed, and operated. Careful siting, impact assessments, and mitigation plans can help minimize the potential effects on water, soils, and other environmental resources.
Comparison to Other Energy Sources
When comparing wind power to other energy sources, wind has a relatively low environmental impact. According to a 2022 study published in PubMed Central, wind power overall results in a much lower environmental impact compared to coal and natural gas power plants (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9360340/). The carbon footprint of wind power is significantly lower than fossil fuels like coal and natural gas that emit high levels of greenhouse gases.
Compared to solar power, wind power can have a larger land use footprint as solar panels can be installed on rooftops while wind turbines require open areas. However, a 2017 Carbon Brief analysis found that wind has an amazingly low carbon footprint comparable to solar and nuclear power (https://www.carbonbrief.org/solar-wind-nuclear-amazingly-low-carbon-footprints/).
Overall, wind power has environmental advantages over fossil fuel energy sources like coal and natural gas in terms of lower emissions and impact on climate change. While wind may require more land than rooftop solar panels, wind has similar environmental benefits as other clean energy sources like solar and nuclear.
Conclusion
In conclusion, wind energy has several notable environmental effects that should be weighed when considering it as an energy source. On the positive side, wind turbines produce no air pollution or carbon emissions during operation, helping combat climate change. The small land footprint of turbines allows agricultural activities like grazing to continue. However, wind farms can negatively impact wildlife through habitat disturbance and direct mortality from collisions. Turbines also generate noise and visual impacts for nearby residents. Overall, wind energy has fewer detrimental effects than fossil fuel sources, but its environmental profile depends on proper siting and mitigation strategies to minimize harm to species and habitats. With care taken to avoid sensitive environments and populations, wind power can provide clean energy while protecting our environment.
