Methane is a highly potent greenhouse gas, with more than 80 times the climate warming impact of carbon dioxide over the first 20 years after it is released. Studies show that if methane leaked at a rate of greater than 3%, there would be no immediate climate benefits from retiring coal-fired power plants in favor of natural gas power plants. The good news is that a 2.3% leak rate suggests that natural gas power plants are slightly more beneficial to the climate in comparison to coal-fired power plants. However, the results of our studies also showed that power plants could show more substantial benefit to the climate if the industry reduced the total methane leakage rate to 1%, which many of our industry partners believe to be achievable.
In addition, natural gas power plants can change output more quickly than large coal plants, supporting the integration of variable renewable sources, such as wind and solar power. Industry, and some environmental groups see natural gas as a “bridge fuel” that helps with the integration of renewable energy into electricity systems.
However, there is one additional, clear difference between coal and natural gas power plants. For coal plants, almost all of the climate impact is due to burning the coal, while for natural gas, the climate impact is a combination of combustion and methane emissions – both leaks and venting. Changing how coal burns is very difficult. Reducing natural gas leakage is a very real possibility.