Wind Energy Reducing 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 2015, the 191 million megawatt-hours (MWh) generated by wind energy avoided an estimated 132 million metric tons of CO2, the equivalent of reducing power sector CO2 emissions by 6%, or the equivalent emissions of 28.1 million cars.
The 9,400 MW of wind power capacity under construction at the end of 2015 is expected to reduce almost 23 million metric tons of additional CO2 per year when it is operational—the equivalent of reducing power sector CO2 emissions by another roughly 1%.
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.
Sulfur Dioxide and Nitrogen Oxide Savings
According to EPA’s 2014 AVERT tool, the electricity generated by wind energy in 2015 displaced approximately 176,000 metric tons of sulfur dioxide (SO2) and 106,000 metric tons of nitrogen oxide (NOX), representing $7.3 billion in avoided health costs last year alone. The tons of SO2 and NOX pollution avoided just in 2015 carry a public health monetary value of more than $5.4 billion and $1.8 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.
On average, wind generation today will avoid approximately 0.69 metric tons of CO2 for every megawatt hour of wind generation. A typical new wind turbine will avoid over 4,200 metric tons of CO2 annually, nearly 900 cars worth of CO2 emissions.