Coal-fired power plants are king again as sub-zero temperatures sent demand for heating and electricity soaring on the East Coast Friday in the largest energy market in the nation.

Coal outpaced both natural gas and nuclear power plants in the PJM market, which extends from the Midwest to Washington, according to real-time updates provided by the grid operator PJM Interconnection.

Coal provided nearly 20,000 megawatts more electricity throughout the day Friday than its primary rival natural gas and over 10,000 megawatts more than nuclear power plants.

One megawatt of electricity can provide 750-1,200 homes with power, depending on how much demand there is on the system, according to experts.

The PJM breakdown looked like this: Coal at 45,842 MW; nuclear power at 35,514; and natural gas at 25,927. Renewables provided 3,086 MW. Coal, nuclear and natural gas are the three dominant sources of 24-hour power on the grid.

The surge in coal electricity production is expected to remain high going into next year because of a bump in the price of natural gas, which has become the dominant source of electricity in recent years.

The current cold snap could provide a much-needed boost for the Trump administration's proposal to provide market-based incentives in PJM and other markets to ensure coal plants are not pushed out of the market by natural gas.

The proposal is being considered by the Federal Energy Regulatory Commission, which intends to vote on the proposal in January. The proposal was supposed to be approved this month, but the commission's newly appointed chairman, Kevin McIntyre, said he required an additional 30 days. The plan is being adamantly opposed by scores of industry groups from the oil sector to renewables.

Energy Secretary Rick Perry, who sent the proposal to FERC, cited the January 2014 cold snap, called the "polar vortex," to underscore the need for the coal plant incentives. He often recalls that if it were not for coal, the grid would have failed during a critical time when natural gas supply became constrained.

Adding to the administration's support for the coal industry, new federal data released Thursday showed that coal ended on a high note during the last week of 2017.

U.S. coal production for the year totaled 760.4 million short tons, which is 6.4 percent higher than a year ago, according to the Energy Information Administration's last weekly coal report for 2017. The agency is the Energy Department's statistical and analytical arm.