Wind Energy Reduces Greenhouse Gas Emissions
Carbon Dioxide Savings
Clean wind energy avoids significant carbon dioxide (CO2) emissions annually by displacing generation from fossil fuel power plants. In 2016, the 226 million megawatt-hours (MWh) generated by wind energy avoided an estimated 159 million metric tons of CO2, the equivalent of reducing power sector CO2 emissions by 9%, or the equivalent emissions of 33.7 million cars.
The 10,432 MW of wind power capacity under construction at the end of 2016 is expected to reduce almost 24.2 million metric tons of additional CO2 per year when it is operational—the equivalent of reducing power sector CO2 emissions by another roughly 1%.
On average, wind generation today will avoid approximately 0.70 metric tons of CO2 for every megawatt hour of wind generation. A typical new wind turbine will avoid over 4,300 metric tons of CO2 annually, nearly 900 cars' worth of CO2 emissions.
Sulfur Dioxide and Nitrogen Oxide Savings
Wind energy also greatly reduces a variety of health-harming air pollutants, including smog-causing sulfur dioxide (SO2) and nitrogen oxides (NOx), which helps reduce rates of asthma and other respiratory issues. According to EPA’s 2015 AVERT tool, the electricity generated by wind energy in 2016 displaced approximately 178,000 metric tons of sulfur dioxide (SO2) and 110,000 metric tons of nitrogen oxide (NOX), representing $7.4 billion in avoided health costs last year alone. The amount of SO2 and NOX pollution avoided just in 2016 carry a public health monetary value of more than $5.5 billion and $1.9 billion, respectively, based on cost assumptions provided by a Harvard School of Public Health study.*
Wind power typically displaces generation from fossil fuel power plants, and as a direct result, reduces greenhouse gas emissions, other air pollutants, and other environmental impacts of fossil fuel consumption. Electricity produced by a wind project results in an equivalent decrease in electricity production at another power plant. Due to its low operating costs, wind is typically used to displace generation from the most expensive power plant that would have operated otherwise. The power plants being ramped down are almost always fossil-fired units because of their high fuel costs. Wind energy is also occasionally used to reduce the output of hydroelectric dams, which allows such facilities to build up their reservoirs of water so they can be used later to replace more expensive generation from fossil-fired power plants.
Environmental benefit calculations use EPA’s “AVoided Emissions and geneRation Tool” (AVERT). AVERT calculates the pollution reductions provided by renewable energy and energy efficiency by statistically determining which fossil fired power plants are most likely to have their output reduced due to the addition of renewable energy or energy efficiency.