Environmental Impact of Wind Energy

Renewable energy is energy from a resource that naturally replenishes itself. Using renewable energy offers a long list of health, economic, and environmental benefits. We rely heavily on fossil fuels to generate power for daily use. However, non-renewable fuels produce dangerous gasses that lead to global warming. 

Wind energy doesn't have overwhelming adverse environmental effects like fossil fuels. Wind power is one of the cleanest and most eco-friendly ways to generate electricity. It is very sustainable because it doesn’t produce excessive amounts of carbon emissions or other forms of pollution. 

This article explores wind, the history of wind-generated energy, the mechanics of a wind turbine, and the environmental impacts of wind energy development. 

What is Wind Energy 

So far back in history, humans have harnessed the power of wind energy. Our ancestors used wind-generated energy to sail ships on rivers and oceans. In the 10th century, Persians had vertical-axis windmills that helped them grind their grains. The Chinese also had similar approaches to harnessing wind energy as early as the thirteenth century.

The wind became an energy source for grinding, moving water vessels, and pumping water. Subsequently, wind energy harnesses the movement of air to create mechanical power and electricity. The wind’s kinetic energy turned windmills, now known as wind turbines, a technology that facilitates the use of wind for electricity.

Wind turbines have blades attached to a tutor. As the wind blows, it spins the blades, and the rotor, by extension, spins a generator that generates electricity. These blades face the wind directly. There are two types of wind turbine equipment: horizontal-axis wind turbines (HAWTs) and vertical-axis wind turbines (VAWTs).

The horizontal-axis wind turbine has two to three long, thin blades similar to an airplane’s propeller, while the vertical-axis wind turbine has short and wider curved blades. VAWTs are like the blades of an electric mixer. Wind turbines produce energy when the wind speed reaches 9.66-14.48 km/hr.

The length of turbine blades influences the amount of electricity it can produce. Small wind turbines can produce 10 kW for a single home, while the largest wind turbine can generate up to 15,000 kW of electricity.

Read more: How do wind turbines work? 

Wind Energy as a Form of Renewable Energy

Renewable energy is energy from infinite natural resources. Wind-generated energy is a type of renewable energy because it is inexhaustible. Other examples of renewable energy are solar, geothermal, Bioenergy, ocean, and hydropower. Harnessing electricity with wind releases zero carbon emissions into the atmosphere, making it a sustainable power source.

The wind is one of the largest renewable energy sources after solar energy. Amongst the many advantages of renewable energy, we can harness it endlessly, saving our climate system from the emissions produced by using non-renewable fuels. 

There are wind power plants in many countries around the world. Operating a wind plant is much more than erecting wind turbines in windy regions. It requires adequate planning and an environmental survey. 

At the end of 2022, the Global Wind Report (Global Wind Energy Council) recorded 906 gigawatts of wind energy⁵. This energy is enough to upset the production of 1.1 billion tonnes of CO2 globally.

The United States has 42 states that use wind energy as of 2021. These 42 states produced up to 380 million kWh of electricity, with Texas, Iowa, Oklahoma, Kansas, and Illinois producing 56% of the wind electricity. In 2020, China, the United States, Germany, the United Kingdom, and India were the top wind energy generators.

China produced 288.32 gigawatts at the end of 2020, while the United States generated 122.32 gigawatts. Germany and India produced 62.85 and 38.63 gigawatts, respectively.

Types of wind farms

A wind farm is a collection of wind turbines that generate electricity in the same location. We can refer to a wind farm with other names, like wind park, wind energy plant, or wind power station. The size of a wind farm solely depends on the amount of electricity needed. Small wind energy plants contain a few turbines, while the largest wind farms contain miles of turbines. 

There are three major types of wind energy farms. They are:

Onshore wind farm 

Onshore wind farms are a group of turbines on land. Wind farm construction on land is usually undertaken in rural areas, fields, and less populated places because of the undisturbed, natural air movement. 

Land-based wind power facilities were the first to generate power since the 1880s. In December 1980, US Windpower installed the world’s first wind farm. On the shoulder of a Crocheted mountain in southern New Hampshire, the farm contained 20 30 kW watts-rated wind turbines.

Launched in 1991 in the United Kingdom, the Delabole wind farm was the first commercial land-based wind farm. As of 2020, there are over 1,500 onshore farms across Europe.

You can easily connect land-based farms to a utility power grid or combine them with a solar system. They mostly use this type of energy farm for communicating and pumping water. Still, it is also a perfect way for homeowners, farmers, and ranchers who live in windy regions to produce electricity sustainably. 

Read more: The History of Wind Energy & Turbines.

Offshore wind farms

Offshore wind farms are a group of turbines in large bodies of water. There is a higher velocity of wind offshore than on land. Unlike land-based wind energy, the energy sector is exploring all the possibilities offshore wind developments can offer because of its minimal impact on people and the land-based environment. 

You can build offshore wind farms on lakes, fjords, and sheltered coastal regions. Offshore wind turbines mostly have fixed foundations underwater. They do not have to be installed in areas with deep water levels. A shallow water area of about 60 meters is fine. Recently, floating wind turbines have been introduced on offshore wind farms.

The world’s largest floating offshore wind farm is in Kincardine, off the coast of Scotland. Off the coast of Yorkshire is the world’s largest fixed-foundation offshore wind farm. Hornsea 2 has 165 turbines that produce offshore wind energy. Combined with the first offshore farm created 30 years ago, Hornsea 1, it generates enough offshore wind power to power 2.5 million homes.

In December 2019, Deepwater Wind Company commissioned Block Island Wind Farm, America's first commercial offshore wind energy farm. As of 2020, there are up to 40 ongoing offshore wind projects in America.

An advantage of floating turbines on an offshore wind farm is the ability to tap into strong wind speeds in areas further into the sea. However, others prefer fixed-foundation wind energy because it is less expensive to install.

Read more: What is Offshore Wind Energy? Definition and Growth

Distributed wind

Distributed wind energy comes from wind plants close to the end user. It refers to the varieties of small, modular power-generating technologies that are combinable to improve the electricity delivery system. 

It works well for individuals, businesses, and communities that want to reduce their carbon footprint and retail power costs, support grid operations, enhance backup power, and transfer electricity to remote houses not connected to the central grid. 

The installation of distributed wind turbines ranges from less than a 1-kilowatt off-grid wind turbine powering communications to a 15-kilowatt wind turbine for a small home and farmhouse to a 100-kilowatt wind turbine at an industrial facility or university campus.  

The Environmental Impacts of Wind Energy

Assessing the ecological effects of wind-generated power, researchers found more positive effects of wind-generated energy. This doesn’t mean it doesn’t have some measure of adverse environmental impacts. For better wind power generation, we need to find solutions to the problems it causes. 

Wind energy has two major environmental impacts: direct impact on organisms and habitat structures and functions. Some of these environmental impacts are:

1. Wind turbine blades threaten every bird flying in the vicinity. 

This ecological impact has a direct impact on the avian species/organisms. The first commercial wind power plants built in the United States had zero regard for the well-being of birds and bats. The facilities built in California during the 1980s did not consider the avian species during the planning, construction, and operation stages. 

The songbird species, commonly found in terrestrial environments, is a regular victim of wind turbines. At a Vermont wind facility, Searsburg, turbine blades killed 11.7 marine birds per megawatt. It was a direct collision.

Another study at 31 facilities showed that wind power installations and generations affect waterbirds, waterfowls, shore birds, diurnal raptors, owls, feral pigeons, house sparrows, and rock doves. The blades are a problem for bird species, especially during their migration seasons.

Apart from a collision with turbines, the change in air pressure from the rotation of these blades can also prove a threat to flying bats. However, the National Wind Coordinating Committee reviewed these fatalities, deeming them non-threatening because they weren't noticeable. 

Low bird and bat fatality rates don't mean we can abandon the number of deaths caused by generating wind power.

The Bats and Wind Energy Cooperative proposes keeping turbines still at low‌ wind speeds to mitigate this. They discovered that keeping turbine blades still at low wind speeds prevents the deaths of bats and other avian life species without affecting power generation³.

2. Wind projects change the structure of the ecosystem.  

The construction of wind energy plants affects the terrestrial and marine environment differently. It affects the habitats of various animals. It also affects vegetation and other landscape components for resident and migratory species present before the construction of wind turbines. 

These disturbances vary according to site differences like topography, vegetation types, previous land use history, size, the distribution of wind turbines, and the number of existing roads. 

Constructing wind facilities requires the creation of open spaces. These open spaces create minimal climate change by increasing light and wind speed. These microclimate changes lead to increased temperature, reduced humidity levels, and soil moisture of affected land space.

Animal behavior modification is next on the list of environmental effects of constructing a wind facility. They construct forest roads to aid easy transportation, which can change the behaviors of some animals. For instance, black bears avoid roads with heavy traffic because they are easy prey. Also, roads are a problem for land snails and other small mammals. 

Road construction for wind facilities also damages the soil bed. It changes marine ecosystems' soil density, temperature, water content, light, dust, surface water flow, and sedimentation flow. The edges of the roads contain pollutants and nitrogen compounds, which change the food chain relationship between plants, insects, and the predators of insects. 

Also, one of the environmental effects of forest roads is the increase in the distribution of invasive species. Altered habitats, the increased stress of native species, or the complete removal of native species leads to an abundance of invasive species.

However, on the other hand, while harming some aspects of the system, offshore wind turbines have also created artificial reefs. As such, new aquatic habitats are created.

3. It causes noise pollution.  

Onshore and offshore wind energy production produces a lot of noise. These noises affect land animals and marine species, too. Operating offshore wind energy infrastructure minimizes human impact because it is in the middle of a water body, far away from major civilizations. 

However, the marine ecosystem directly interacts with the turbines during construction and operation. Research showed that the foundation construction phase produces up to 260 dB, while the cable placement produces 178 dB.

The low-frequency noise levels influence marine mammals' and birds' behaviors around the area of the offshore wind energy facility. According to the German Federal Ministry of Environment, operational noise emissions from the turbines don't damage the hearing capacities of marine animals. However, underwater noise can disrupt the ability of marine wildlife to find prey because sea mammals depend on their echolocation¹.

Also, the noise from a wind project can incite panic and increase the intensity of sea animals' vocal calls. If the area is where fishes migrate to, feed, and mate, it causes problems. The fish will avoid the area completely and look for new locations with abundant food for migration and breeding seasons.

People who live close to land-based operating wind turbines will also suffer from the varying loud noises they produce during operation. Living close to it will be difficult for someone sensitive to vibrations because some people feel worrying amounts of vibrations from the wind turbines.

Read more: Environmental Impact of Noise Pollution.

4. It reduces the release of greenhouse gas emissions into the atmosphere. 

Wind energy is a renewable energy that benefits the environment more than it damages it. Using wind as the source of energy generation saves us from the harmful greenhouse gas emissions produced by the conventional resources we use to produce electricity. 

We mainly use fossil fuels to produce energy. However, burning these fuels causes terrible environmental effects, resulting in rising global temperatures. Carbon dioxide emissions from fossil power plants break the ozone layer, leading to climate change. This change affects every living organism, causing erratic changes and damages like loss of habitats, food, irregular atmospheric temperature, weather, etc. 

Operating wind turbines produces the least carbon emissions among other renewable energy sources. A wind turbine produces 2 to 29 g CO2e/kWh. The only emissions attached to wind energy projects are from manufacturing the materials used to construct wind turbine components and the emissions released during transportation².

5. It poses a danger to the aviation industry. 

Tall wind turbines can cause problems for pilots and their airplanes mid-flight. Potentially unable to see the tall structures in their path, crashes are possible. The Federal Aviation Administration placed a mandate that requires wind turbines that are over 200 feet high to have red or white lights for aviation safety. 

These lights prevent pilots from crashing into them at night. However, pilots don’t need the light to see during the day because the turbine structure is typically white⁴.

6. Wind turbines create shadow flickers. 

Another one of the ecological effects of wind facilities is the creation of false shadows. On sunny days, the blades of wind turbines cast shadows on the ground as they rotate. Creating alternate light intensity, referred to as a "shadow flicker."

The shadow flickers these blades create can be a nuisance to human eyes. However, they can be a major issue depending on the country. The United States didn't identify the shadow flickers as a problem, but Northern Europeans declared it a problem. It is a problem because of Northern Europe's high latitude and low sun angle, especially during the winter.

7. It improves the economy. 

Apart from the ecological advantages, we gain economic benefits from harnessing the kinetic energy in the wind. A wind energy project provides various employment opportunities to the public. Job offers in the wind industry include heavy-duty truck drivers, wind turbine constructors, researchers, operation and maintenance officers, etc. 

The National Renewable Energy Laboratory and the U.S. Department of Energy's (DOE's) Wind Energy Technologies Office organized research on the supply chain. They concluded- by 2050, the wind energy industry will support up to 600,000 job opportunities.

Also, electrical energy from wind will reduce price spikes and supply disruption often experienced. DOE expects consumer savings of $280 million by 2050.

In addition, wind facilities generate tax for the local government. In 1998 and 1999, Iowa installed a 240 MW wind capacity that produced $2 million in annual tax payments to countries and schools. Another example of this is Alameda County, in California. The government collected $725,000 in property taxes in 1988.

Further reading: Advantages and disadvantages of wind energy

Conclusion 

We gain economic and environmental advantages from using wind as our renewable energy source. With renewable energy development rising rapidly worldwide, researchers focus on electricity generated with offshore wind because it has fewer negative environmental impacts. 

However, the bad environmental impacts of onshore wind are avoidable through better siting wind plants. With better locations away from the path of migratory birds, we’ll avoid multiple bat and bird deaths. The environmental sustainability of wind power comes with many more benefits than damages.

To learn more about wind energy development, check out the wind development associations in your region. Some examples of these associations are the Canadian Wind Energy Association and the American Wind Energy Association.