Winter storms Gerri and Helen, which swept across the United States this week, highlight the need to add transmission capacity in the country, according to Federal Energy Regulatory Commission Chairman Willie Phillips.
The Southwest Power Pool, which runs the grid from North Dakota to north Texas, imported a record 6.8 GW to help keep power flowing in its footprint, Phillips said Thursday at FERC’s monthly meeting.
In a move that could bolster the U.S. grid, Phillips said he expects in the “coming months” that the agency will revamp its requirements for transmission planning and cost allocation.
A new transmission planning rule would build on FERC’s updated interconnection requirements — issued in July — for connecting generator and energy storage projects to the grid, he said.
A new transmission planning rule would help ensure the grid remains robust, reliable and responsive to future energy needs, Phillips said.
“I'm confident that the collective expertise and commitment of FERC will lead us to equitable and forward-thinking transmission solutions that will stand the test of time,” he said.
During a media briefing, Phillips said he had “extreme confidence” that FERC’s commissioners have the working relationships needed to move a regional planning and cost allocation rule forward in the “very near future” and that “there's nothing that I know … that can make me believe that we can't get this work done.”
FERC is also exploring the possibility of taking steps to bolster transmission capacity between regions, Phillips said. Those efforts are running alongside a North American Electric Reliability Corp. study on the issue, he said, noting the study has started and may not take 18 months, the amount of time Congress gave NERC to do it.
“We are working on these two projects in parallel so that when NERC concludes its study, FERC is ready to act immediately,” he said.
Interregional transmission appeared to help grid operators deal with bitterly cold weather in the past week, according to FERC Commissioner Allison Clements, who noted the PJM Interconnection exported about 12 GW on Wednesday morning.
“It is worth taking a moment to consider the encouraging aspects of this week’s experience,” Clements said. “We can meet the challenges of extreme weather with proactive steps.”
Based on initial reports, it appears that lessons learned from Winter Storm Uri in 2021 and changes that have happened since then contributed to supporting the grid this week, according to Clements.
Since Uri led to rolling blackouts across Texas, the Electric Reliability Council of Texas, which runs most of the state’s grid, tripled its battery storage to 5 GW and doubled its demand response capacity to 4 GW, according to Clements.
Initial reports suggest that the Texas thermal power plant fleet performed better during this week’s bad weather compared to previous years, and wind farms provided 30% of ERCOT’s peak demand while solar farms produced a record 14 GW, she said. Also, batteries helped keep wholesale power prices relatively low during the morning ramps in ERCOT on Monday and Tuesday, according to Clements.
Christie warns on power plant retirements
While grid operators and utilities generally managed to keep the lights on during this week’s extreme weather, FERC Commissioner Mark Christie said that was only possible because they had enough dispatchable power supplies provided by gas- and coal-fired power plants and nuclear generating stations.
On Wednesday morning, during PJM’s peak demand period, gas-fired power plants produced 41% of the grid operator’s electricity, nuclear plants produced 25% and coal-fired generators produced 24%, according to Christie.
During the Midcontinent Independent System Operator’s peak, gas and coal power plants each generated 34% of MISO’s electricity, followed by wind at 20% and nuclear at 9%, he said.
Those numbers indicate the danger posed by the loss of dispatchable generation through power plant retirements without adequate replacements, according to Christie.
“If the pace of retirements continues at the pace it is, the numbers just aren't going to add up,” Christie said. “This is not a commentary against some form of resources. It is simply stating what NERC has been telling us over and over … that if you don't maintain these dispatchable resources until you have an absolutely adequate replacement, we're not going to have the success we had in the last three or four days.”
PJM talks up GETs
Separately, PJM in a Wednesday filing at FERC touted the operational benefit of “grid enhancing technology” during Winter Storm Elliott. FERC is exploring “dynamic line ratings,” which can be used to safely maximize the load on power lines.
PPL Electric Utilities had installed dynamic line rating sensors to measure conductor and environmental data in real time on its Cumberland-to-Juniata transmission line and the DLR ratings on the line during Winter Storm Elliott were higher than the ambient adjusted ratings PJM would have operated to otherwise, the grid operator said.
“Had PJM not had the higher dynamic line ratings, PJM would have had to take action to re-dispatch the system to maintain reliability,” the grid operator said. “Such action would have been very difficult under the critical operating conditions.”
