LITTLETON, Colorado, Jan 23 (Reuters) - Power generators have boosted output from high-polluting coal and oil-fired power stations this year to help battle an extended cold snap enveloping much of the country.

Coal-fired power production across the lower 48 states was the highest since at least 2019 during Jan. 1-22, and up 6% from the same period last year, data from LSEG shows.

Production from plants that burn fuel oil - used mainly as a backup to gas-fired plants - soared 170% from the same days a year ago to the highest in three years.

Output from natural-gas-fired plants - the primary power source in the U.S. - declined by 2% from last year's record levels, but is holding close to the highest production rate ever for this time of year.

The broad swell in fossil-fuel-fired output came just as large swathes of the country got slammed by an extended bout of below-normal temperatures, which forced power firms to lift output from every available resource.

But the fossil boom also took place just as the second administration of U.S. President Donald Trump vowed to step up output and use of fossil fuels in U.S. energy production.

That raises the question of whether power producers now feel they have a license to continue deploying high levels of fossil fuels for power; or will they continue to build up clean generation capacity and phase out fossil use over the long run?

COLD SNAP

Temperature readings across several parts of the United States plunged well below normal for several days so far in 2025.

Average recorded temperatures across the Midwest, Atlantic Coast, the Plains states and throughout the South all swooped far below the long-term averages recorded in those areas, according to LSEG.

To meet the resulting rise in demand for heating, power producers throughout the country cranked production from all available sources from Jan. 1-22.

Nuclear power plant output climbed by 3.7% from the same days in 2023 to 2.14 million megawatt hours and the highest since 2020, while wind output climbed 1.5% to a record 1.2 million MWh.

However, a nearly 3% decline in output from hydro plants - due to an enduring drought in key areas - ensured that power firms had to also lift production from fossil fuel facilities.

Coal-fired production was 2.5 million MWh during the Jan. 1-22 period, compared to 2.3 million MWh the year before, while fuel-oil-fired plants lifted output to 44,420 MWh from just 16,420 MWh over the same dates in 2023.

Gas-fired plants generated 4.38 million MWh of power from Jan. 1-22, down 2% from the year before.

Output from solar farms was 386,112 MWh over the first three weeks of 2025, up 51% from the same dates in 2023.

In all, the temperature plunge across such a large swathe of the country for such an extended period clearly necessitated the use of all power resources so far in 2025, including the use of some of the highest-polluting plants in the country.

Once temperatures return to normal, power trackers will be monitoring whether generation firms dial down fossil fuel use again, or if the strong support for fossil fuels in the White House results in a sustained rise in the burning of polluting fuels throughout the U.S. generation system.

The opinions expressed here are those of the author, a market analyst for Reuters.

Sign up here.

https://www.reuters.com/business/energy/us-power-firms-crank-up-dirty-fuel-use-fight-cold-snap-maguire-2025-01-23/