More than 120 U.S. coal plants have either been replaced or converted to different fuels since 2011

Proof of the growing disuse of coal was put on full display this week by new data from the United States Energy Information Administration (EIA), which showed that 121 coal-fired power plants were repurposed between 2011 and 2019, most of them to natural gas.

The effects of that can perhaps be best seen in the energy they provided. As of 2010, 316.8 GW of coal-fired capacity existed in the United States. Within nine years, 42.9 GW of that energy were retired outright, 14.3 GW saw their boilers converted to burn natural gas, and 15.3 GW were swapped for natural gas combined cycle. The EIA credited a mix of stricter emission standards, low natural gas prices, and more efficient natural gas turbine technology for the switch.

Many of these conversions took place in the eastern half of the country, due to those plants’ age and smaller capacity. Of 104 plants over 50 years old, 86 converted their boilers to burn natural gas, although some plants did not entirely remove the capability to burn coal, in case it became economical again. Of those companies undertaking conversion, Alabama Power Co. swapped the most, altering 10 generators at four coal plants between 2015 and 2016 to bring them in line with the requirements of the U.S. Environmental Protection Agency. Those 10 generators amounted to 1.9 GW of capacity.

Going forward, the EIA expects coal-fired generation to continue to fall by the wayside and conversion to rise, particularly in the Midwest and Southeast. So far, eight more natural gas-fired combined-cycle plants are planned, five of which are already under construction to replace existing coal plants.

Conversion to natural gas-fired combined-cycle plants tends to be the less preferred method for switching coal plants to natural gas burners, the EIA noted, even though they provide greater generating capacity than the coal plants they replace. Instead, most plants have tended toward the approach to convert boilers of coal-fired steam plants to burn other types of fuel.