The popularity of coal as an energy source in the U.S. is largely due to its price. For example, the cost of coal for electric generation in 2019 was 2.02 U.S. dollars per million British thermal units, compared to 2.89 U.S. dollars for natural gas. In the same year, one metric ton of thermal coal cost approximately 80 U.S. dollars. The cost of coal depends on the carbon content which can change the energy density that coal contains. Coal consumption is rapidly decreasing in the United States due to increased availability of renewables and natural gas, as well as stronger environmental regulations. The U.S. Environmental Protection Agency has regulated coal plants due to mercury pollution, smog, and climate change.
Coal plants in the United States have been the focus of recent energy policy under the Trump administration. A large majority of coal plants in the U.S. where regulators set rates have operating expenses that exceed revenue. In these regions, utilities and regulators often force plants to stay open in order to maintain grid stability. Despite this, many utilities are planning to retire coal plants while replacing them with natural gas and renewables.