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| Fig. 1: An aerial view of the Power County wind farm - Power County, Idaho with Nordex N100/2500 turbines. (Source: Wikimedia Commons) |
Wind energy is a greener alternative to fossil fuels such as oil, gas, and coal. But how much do wind turbines contribute to reducing greenhouse gasses in the atmosphere? In this report, I will analyze the mass of CO2 saved by wind turbines worldwide and compare it to annual CO2 emissions from fossil fuel energy.
The International Renewable Energy Agency (IRENA) reported that in 2021 wind power industries across the globe (see Fig. 1) produced a total of 1,838,264 GWh of electricity. [1] The energy delivered can be converted into CO2 by
| M | = | E ρ |
( | mCO2 mC |
) |
where E is the energy produced in Joules, ρ = 2.4 × 107 J kg-1 is the heat density of coal, mCO2 = 44 u is the molar mass of CO2, mC = 12 u is the molar mass of carbon, and M is the mass of CO2 released by an energy-equivalent coal combustion reaction. [2]
We can find that, in total, wind energy saves
| 1.828 × 107 GWh
× 3.6 × 1012 J GWh-1 2.4 × 107 J kg-1 |
× | 44 12 |
= | 1.011 × 1012 kg |
or 1,011 million tonnes of CO2 every year.
According to the BP Statistical Review of World Energy, worldwide CO2 emissions in 2021 due to energy recovered from oil, gas, and coal were 33,884 million tonnes. [3] In the last ten years, this number has not fallen below 31,904.6 million tons in 2011, with a mean of 33,015 million tons per year. Given the current number of wind turbines and the rate of fossil fuel consumption, wind energy offsets 3% of the greenhouse gas emissions from oil, gas, and coal combustion.
© Sephora Ruppert. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute, and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] "Renewable Energy Statistics 2023," International Renewable Energy Agency, 2023.
[2] I. Hore-Lacy, Nuclear Energy in the 21st Century, 4th Ed. (World Nuclear Association, 2018).
[3] "BP Statistical Review of World Energy 2022," British Petroleum, June 2022.
[4] "WindVision: A New Era for Wind Power in the United States," U.S. Department of Energy, March 2015.
