Carbon Footprint of Wind Turbines
Renewable energy is slowly becoming normalized around the world due to decreasing costs of the technology, the equitable nature of sun and wind-powered energy, and global pressures related to climate change. The impacts of global warming are becoming more and more serious and many believe that we must act swiftly and efficiently in order to slow down and counteract its effects.
In an effort to lower carbon emissions, both corporations and the general populace are looking to utilize more green energy sources. Yay!
This includes wind farms, solar panels for electricity generation, and even nuclear power (though nuclear power is controversial given all of the potential negative outcomes as well - we'll dive into all things nuclear power in a different article).
Wind turbines play a very important role in the renewable energy mix. Wind power does not rely on any finite natural resources (just wind!) and incorporates technology that has been utilized for centuries. To be a viable source of sufficient power to our growing population, many wind turbines need to be placed in viable areas. Once constructed, the resources required to maintain power production are minimal compared to traditional energy generation methods such as coal-fired power plants.
This article will dissect the purpose of wind turbines, the carbon footprint of wind turbines, and what kind of environmental benefits they provide.
How do we Define Wind Energy?
Fun fact: Most people don't know that wind energy is actually a form of solar energy. The sun heats Earth's surface at varying degrees due to the unevenness of its surface. Combined with Earth's rotation, the discrepancy in temperature causes the flow of air in an effort to reach an equilibrium - thus, wind.
Onshore Wind Energy Generation
There are two main types of renewable energy that are related to wind power - Onshore and Offshore wind turbine farms.
Onshore generation pertains to using these turbines on land. This type of energy generation is generally cheaper, easier to construct and transport, and simpler to maintain than its offshore counterparts. However, onshore wind is usually a bit more unpredictable as well, which lessens the efficiency, energy potential and corresponding profit for energy developers.
Prior to constructing a wind farm, energy developers will engage in detailed, multi-year studies to understand the wind potential in any given area. This is true for onshore or offshore projects, but variability is always possible. The minimum threshold to efficiently harvest wind power is an annual average of 4MPH for smaller turbines and 13MPH for larger ones.
Currently, the largest onshore wind farm is located in China and is able to produce more than 8 gigawatts of electric energy from its 7,000 wind turbines!
Offshore Wind Energy Generation
Offshore wind generation shouldn't be confused with offshore hydroelectric power production. Though this technology uses turbines, those blades are located under water and leverage the tide.
Compared to onshore renewable energy solutions, offshore wind farms tend to have greater potential capacity for energy production due to more powerful and predictable wind patterns. Offshore wind farms tend to engage larger turbines to account for greater wind, though this isn't always true. (Note: The energy potential of any turbine - measured by its MW capacity - can be loosely correlated to its size.)
The drawback of such a solution is that construction is more difficult, costly and strenuous, and the costs of the turbines themselves are considerably more expensive due to size and durability requirements. Depending on perspective, these wind farms are generally considered to be less obtrusive than their onshore counterparts, though this writer isn't convinced of this particular argument.
The largest offshore farm has just 87 turbines producing an incredible 660 megawatts of power! If you were to place 1,000 offshore turbines, they would generate more electricity than the 7,000 onshore ones. Now that's efficiency!
How Big is the Carbon Footprint of Wind Turbines?
A carbon footprint can be defined as the amount of greenhouse gas emissions that are associated with consumption - this could be a product/thing or a person. We humans produce vast amounts of greenhouse gas emissions (people tend to think of these on a carbon dioxide equivalent or CO2e) that drastically affect the environment and our the livability of our planet for all species.
Generally, the slope of greenhouse gas emissions became notably steeper during the Industrial Revolution when coal and other fossil fuels started to be utilized to establish mechanized industrial production techniques. Population growth followed suit, kicking off a vicious cycle of production and consumption. There are lots of resources on the root causes of climate change and we'll leave the topic to scientists and journalists. Back to wind turbines!
As far as wind turbines are concerned, their carbon footprint is virtually non-existent. Just a single wind turbine can produce many a kilowatt-hour of energy while having virtually no negative effect on the environment.
Complete Carbon Footprint of Wind Power Turbines
A life cycle assessment (LCA) is a methodology for evaluating the potential environmental impacts of a product throughout its entire life cycle, inclusive of raw material extraction and end of life. For wind power, life cycle emissions considers not only the direct emissions from the energy production phase, but also construction, the raw materials used, associated equipment required to transmit the energy production and dismantling.
For wind power, the primary driver of a turbine's carbon footprint is the construction of the turbine itself due to the raw materials used. Between 75-85% of the total carbon footprint associated with an onshore or offshore wind turbine can be associated with its manufacturing and construction. This means that the environmental impact of wind farms are primarily front loaded, but amortize down significantly as the equipment is in its production phase. Steel, concrete and aluminum are just some of raw materials used in the manufacturing process and generally have a high carbon intensity. Estimates suggest the steel used in a turbine accounts for approximately 30% of it's total carbon impact. Turbine blades are generally made of fiberglass and can account for 12-15% of the carbon footprint. Studies are showing that the environmental impacts of wind energy systems are improving as the technologies across supply chains decarbonize and this trend should continue well on into the future as manufacturing processes improve.
Future improvements aside, compared to other forms of electricity production, wind power has one of the lowest footprints around!
Nuclear power plants have the lowest carbon footprint for an energy source, estimated to be 9 grams of CO2e per per kilowatt hour produced. Wind power is not far behind though averaging just 11 g of carbon emitted per kwh of energy produced, and can get even lower with larger offshore turbines like the GE Haliade. By comparison, solar power averages approximately 44 g/kwh, natural gas averages 450-500 g/kwh and coal averages an exceedingly high 900-1,000 g/kwh. Pound-for-pound, or rather kilowatt-for-kilowatt, wind is one of the most carbon-efficient methods to generate electricity.
How do Wind Turbines Fight Climate Change?
Since the Industrial Revolution, Earth's global average temperature has been on the rise and greenhouse gases continue to accumulate in our atmosphere. Greenhouse gases effectively act as a blanket, limiting the ability for the atmosphere to release heat.
Renewable sources of energy are critical towards our efforts at reducing the potential impacts of global warming. Reducing emissions by leaning on clean energy is one of the primary tools at our disposal.
And as one of the most carbon-efficient forms of clean electricity, the electricity generated from wind power should grow considerably in the years to come.
Benefits of Wind Energy
- Better air quality for all due to non-existent carbon dioxide release - Public health officials note the negative effects greenhouse gas emissions and pollution can have on our health. And since carbon-intensive fossil fuel plants like coal and natural gas are often located in poorer areas of the world, the health benefits are seen to a greater extent in disadvantaged communities.
- Independent energy solution - Wind energy doesn't use natural resources while generating loads of electricity. Countries will not have to import electricity or rely on dirty, expensive fossil fuels for their energy use and needs. Wind is true energy independence!
- Virtually no waste products - Many of the materials that go into the construction of a wind farm can be recycled and reused to make other goods and products.
- Mitigation of climate change - Climate action means limiting emissions of harmful greenhouse gases and nitrogen oxides. The cleanest and most efficient natural gas plants still pollute like crazy and don't hold a candle to renewable power sources with a smaller carbon footprint.
- Job availability and employment chances - The renewable energy sector employs more than 11.5 million people globally, and this number is set to steadily increase in the coming years.
- Minimal impact on wildlife and the environment - It is well documented that increased carbon in the atmosphere has profound negative affects on Earth. Ocean acidification is just one example and is a major threat to our complex ecosystems.
Disadvantages of Wind Energy
Though the list of benefits to wind power is long, it is not without some negative impacts.
- Land use - Wind farms require plenty of land to maximize their efficiency and usability. However, once construction is completed, the land use becomes minimal.
- Impact to some wildlife - Turbine blades are massive and can prove to be a threat to flying animals such as birds and bats. If land needs to be cleared, wind farms can also disrupt the habitats of native animals. Modern technology has started to prevent these situations by turning off the turbines during low wind events when bats are most active and by creating natural migration pathways for all of winged and four-legged friends.
- Noise pollution - Wind farms can be loud and can cause distress in people living close to them. One method of fixing this issue is by placing the farms in remote areas where their auditory impact will be lessened.
Final Words
Renewable energy is the future. More and more people, corporations and governments are realizing this which is a positive sign. Citizens have started purchasing solar panels and solar cells to produce electricity for themselves. The energy required to power entire cities is massive, but not unreachable. Some countries already get all of their electricity from renewables including wind, solar, hydroelectric, geothermal and yes... nuclear.
The carbon footprint of each wind farm is remarkably low, making wind power a perfect solution to our need for reduced emissions and less pollution.
