Methane emissions from natural gas-fired power plants are much higher than federal officials have previously estimated, according to a new study.
Researchers from Purdue University concluded in a study published Tuesday that gas plants emit between two and 120 times the amount of methane that the Environmental Protection Agency (EPA) has most recently estimated.
Methane is the main component of natural gas. It is also a greenhouse gas at least 34 times more potent than carbon dioxide.
“There is much more methane being released into the atmosphere by leaky compressors, valves, and industrial hardware,” Paul Shepson, an atmospheric chemistry professor at Purdue, said in a statement.
“The good news from our study is that while emissions are greater than anticipated, natural gas-burning power plants are still cleaner, relative to burning coal.”
The research was published in the journal Environmental Science & Technology.
Natural gas is generally a far cleaner power source than coal, and it has been replacing coal in recent years as prices have fallen and regulations have grown.
But methane leaks can quickly cause gas to outpace the climate effects of coal, since methane is far more potent.
The Purdue researchers said that about 3 percent of gas can leak during the lifecycle of the fuel before it loses its climate advantage. Their research showed that plants generally stay under that threshold.
In the final years of the Obama administration, the EPA and other agencies started to regulate methane emissions.
The EPA and Interior Department both wrote regulations to reduce methane leaks in oil and natural gas drilling, but did not move on to other industries.