1. The impact of wind turbines on the environment mainly includes the following aspects:
①Visual pollution:
Since wind turbines usually need to be built on higher locations, such as hills or coastlines, they may cause visual pollution to the surrounding landscape and natural environment.
The visual impact of wind turbines is one of their most significant environmental impacts. Large wind turbines are usually 100-150 meters high and have high visibility in open areas.
In the Cairn Gorm mountain area of the Scottish Highlands, UK, 30 wind turbines installed in 2016 led to strong protests from residents and environmentalists due to landscape alteration worries. Likewise, in Massachusetts, USA, the Cape Wind project’s plan for 130 turbines in Nantucket Sound was abandoned in 2019 following a contentious 6-year dispute concerning potential visual effects on the seascape.
However, some studies have shown that people’s visual acceptance of wind turbines will increase over time. A long-term survey of Swedish residents showed that five years after the wind farm was built, the number of people who thought it affected the landscape beauty dropped from 76% to 35%.
② Impact on wildlife such as birds and bats:
The rotating blades of wind turbines can endanger flying birds, bats, and other wildlife, potentially affecting their survival and reproduction. To mitigate this risk, certain wind turbine manufacturers implement strategies like employing sound and light alerts or strategically situating turbines along wildlife migration paths.
Case 1: The Altamont Pass wind farm in California, USA, causes the death of about 4,700 birds each year, including protected species such as golden eagles.
Case 2: According to estimates by the U.S. Geological Survey, the number of bird deaths caused by wind turbines in the United States in 2018 was between 140,000 and 360,000. To reduce this impact, some new technologies are being developed:
Radar detection system: It can detect approaching bird flocks and temporarily shut down the wind turbines. After adopting this technology, the Barão de São João wind farm in Portugal has reduced the mortality rate of griffon vulture by 71%.
Painting technology: Norwegian researchers found that painting a wind turbine blade black can reduce bird strikes by 70%.
③ Noise pollution:
The rotation and other mechanical parts of wind turbines may generate noise, which may affect nearby residents. However, since the noise of wind turbines is relatively small, it usually does not have a significant impact on human health. The noise level of modern wind turbines has been greatly reduced, but it may still affect nearby residents.
Case: A Danish study found that when the noise of wind turbines exceeds 42 decibels at night, the risk of cardiovascular disease in residents increases.
However, regulations in most countries require that the noise of wind turbines at the edge of residential areas shall not exceed 35-45 decibels, which is equivalent to the ambient noise level of libraries.
④Impact on land use:
Wind turbines need to occupy a certain area of land, which may have a certain impact on local agriculture, animal husbandry or other uses. But compared with other non-renewable energy sources, wind turbines occupy a relatively small area.
Per the U.S. Department of Energy, a 100MW wind farm covers 20-40 sq km, with only 2-5% as permanent infrastructure, allowing the remaining land for agriculture or grazing. In comparison, a coal-fired plant of equivalent capacity spans about 8-10 sq km, rendering the land unusable for other activities.
2. Future development and reform measures
Despite facing environmental hurdles, global wind power generation is swiftly advancing and has emerged as a crucial tool in combating climate change. To diminish its environmental impact, various measures are being extensively implemented or researched.
Offshore wind power development
To mitigate land and residential impact, offshore wind energy is rapidly expanding. The UK’s Hornsea One project, the world’s largest, boasts a 1.2 GW capacity, powering a million homes. Situated 120 kilometers offshore, it minimizes onshore landscape and residential disruptions.
As per the Global Wind Energy Council (GWEC), global offshore wind capacity hit 6.1 GW in 2020. Projections suggest that by 2030, offshore wind will represent over 20% of total global wind capacity.
Technological innovation
New wind turbine designs are constantly being introduced to improve efficiency and reduce environmental impact. The US startup VB has developed a bladeless wind turbine that generates electricity by vibration rather than rotation. While reducing noise, it greatly reduces harm to birds.
In addition, the Dutch company Vestas is developing fully recyclable wind turbine blades, which are expected to be put into use in 2030. This will reduce the waste problem in the wind power industry.
Ecosystem services
Some studies have shown that wind farms can provide unexpected benefits to ecosystems. A Belgian study found that offshore wind farms can become artificial reefs for marine life and increase biodiversity. Researchers found 39 species of fish and more than 100 invertebrates around the foundation of the wind farm.
In Texas, some farmers have found that the presence of wind turbines actually increases crop yields. This is because the wind turbine blades stir the air, reduce the occurrence of frost, and help crops absorb carbon dioxide better.
Community participation and benefit sharing
In order to increase public acceptance of wind power projects, many countries are promoting community participation and benefit sharing models.
Middelgrunden offshore wind farm in Denmark, 50% of the shares are owned by local community cooperatives. This model not only increases public support for the project, but also brings economic benefits to the local community.
The Scottish government requires all new renewable energy projects to provide community benefit programs, such as providing low-cost electricity or investing in local infrastructure. This policy has greatly improved the social acceptance of wind power projects.
3. Conclusion:
While wind turbines do impact the environment, most effects can be alleviated through technology, planning, and management. Compared to fossil fuels, wind power is far less harmful environmentally.
The International Energy Agency (IEA) notes that wind power cut global CO2 emissions by 624 million tons in 2020. With ongoing technological progress and policy backing, wind power is set to flourish. In turbine design and construction, thorough consideration of local environmental factors is vital to minimize negative impacts and implement measures for ecological protection.
learn more：What is the impact of wind farms on birds? A case study in southern Spain
