Coal "provided the most resilient form of generation" to the country's largest electricity market during this winter's "bomb cyclone" of gale-force winds and record-setting low temperatures, according to the Department of Energy.

In the PJM Interconnection, coal provided "three times the incremental generation from natural gas and 12 times that from nuclear units" between Dec. 27, 2017, and Jan. 8, 2018, DOE's National Energy Technology Laboratory said in a new report (PDF).

It added that "without available capacity from partially utilized coal units, PJM would have experienced shortfalls leading to interconnect-wide blackouts."

The lab looked at activity within six regional wholesale power markets during the "bomb cyclone" that froze the eastern half of the country.

The report comes as the Federal Energy Regulatory Commission considers whether more action by regulators and operators of the power markets is necessary to ensure the resilience of the bulk power system.

FERC Chairman Kevin McIntyre told Congress on Jan. 23 that the system appeared "to have performed relatively well" during the recent cold weather event.

"There were no customer outages resulting from failures of the bulk power system, generators, or transmission lines," he said. "Overall peak load in the eastern market regions was slightly below levels during the 2014 Polar Vortex," the last epic winter weather event.

PJM, which directs transmission in 13 Mid-Atlantic states, examined the bomb cyclone's impact in a February report. "During the cold snap, the grid and the generation fleet performed well. Even during peak demand, PJM had excess reserves and capacity," the grid operator said.

FERC began examining grid resilience after it rejected a pricing proposal from Energy Secretary Rick Perry last September. Perry's plan for grid resiliency would have rewarded only merchant coal and nuclear power plants in certain electricity markets.

NRECA welcomed the commission's decision to evaluate how organized electricity markets compensate electric generation sources.

"Cooperatives support modernizing our nation's energy policy in ways that keep costs affordable, promote system reliability, and avoid imposing undue burdens," NRECA told the commission.

NRECA plans to file comments to FERC on the matter soon.