How long will it take to close every fossil fuel power plant in the US?

If president-elect Joe Biden wants to make good on his promise to decarbonize the US electric grid by 2035, he’s going to have to deal with the power plants. Plants that run on natural gas, coal, and oil are the largest source of carbon emissions in the country, accounting for a quarter of its carbon footprint.

The industry has already started to shut down all those plants: 15% of the US fossil fuel power fleet shuttered between 2009 and 2018. But most of these plants are built to last 30 to 50 years, long enough to pay off the hundreds of millions of dollars it takes to build them. To meet Biden’s 2035 goal, many plants will inevitably have to be switched off before the end of their natural lifespan.

Emily Grubert, a professor of environmental engineering at Georgia Tech, wanted to get a ballpark picture of how many fossil power plants may be “stranded” by climate policy—that is, shuttered before they’ve recouped their costs. If most of the US power plant fleet is expected to live to a ripe old age in mid-century, she reasoned, the clean energy transition could be more expensive than climate hawks are betting on.

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