Dive Brief:
- New England’s grid is less reliable than what consumers pay for due to long power plant start-ups and it gives an unfair advantage to slow-to-start fossil fuel plants over renewable alternatives and storage, an environmental group said Thursday. The Sierra Club cited a report that criticized ISO-New England’s response to capacity problems last Christmas Eve when temperatures plunged.
- The report by Synapse Energy Economics, a public interest research and consulting firm, said the region’s power grid in recent years has “inched closest to blackouts during rapidly developing emergencies, including Winter Storm Elliott” in December. Coal, oil and biomass units included in the report took an average seven to 23 hours to start up, it said.
- ISO-New England spokesman Matthew Kakley said ISO-NE will not comment on the report, but that a short-duration capacity deficiency on Christmas Eve was due to unanticipated outages near the evening peak, leading system operators to use reserve resources to balance supply and demand. He compared it to a savings account that pays for unanticipated home repairs. “The ISO carries operating reserves for just this purpose and the region was several steps away from needing controlled power outages to maintain system reliability,” he said in an email.
Dive Insight:
The criticism coincides with ISO-NE’s Resource Capacity Accreditation in the Forward Capacity Market Key Project to find the best way to account for the reliability contributions of different resources in a grid of the future. Kakley said the project will consider factors such as the performance of intermittent resources, differences in storage resources’ maximum stored energy levels, the ability of gas-only resources to acquire fuel during very cold conditions and differences in resources’ expected outage rates.
Dan Dolan, president of the New England Power Generators Association, said lower than expected temperatures in New England and Quebec drove higher electricity demand Dec. 24, constraining imports. In New England, 2,000 MW less generation than expected was part of the problem, he said.
Hydro Quebec pulled back nearly 1,000 MW, he said, also contributing to a shortage in reserves, Dolan said.
Dolan said the report confuses the forward capacity market and capacity accreditation process. “They’re conflating that with the complex real time operations of the grid,” he said.
Casey Roberts, senior attorney for the Sierra Club’s Environmental Law Program, said a fossil fuel generator that takes 12 hours to start up is “useless for responding to urgent and unpredictable energy emergencies.”
“By making the illogical assumption that all units can start up at a moment's notice, ISO-NE overvalues slow-to-start fossil fuel resources like coal, oil and biomass,” she said in a news release.
Roberts urged ISO-NE to update its capacity market rules “to address this significant shortcoming” and improve grid reliability.
Christmas Eve was the coldest in New England since 1975, according to the National Weather Service. High temperatures were 17 degrees in parts of Connecticut and Providence, Rhode Island; 14 in Worcester, Massachusetts; and 20 in Boston.
The deep chill extended across much of the East. Duke Energy imposed rotating power outages Dec. 24 that left about 500,000 customers in the Carolinas without service as temperatures plunged and energy demand spiked. The Federal Energy Regulatory Commission and North American Electric Reliability Corp. launched an investigation into bulk-power system operations and said the winter storm “underscores the need for the electric sector to change its planning scenarios and preparations for extreme events.”
ISO-NE had just a few hours to prepare for an “unpredicted energy shortage” caused by a winter storm on Dec. 24, with 8,500 MW of available generation on the sidelines unable to start up in time, according to the report. ISO-NE declared a reserve shortage Dec. 24 and the region “got the closest it had been to rolling blackouts since 2018,” the report said.
“While the weather was considerably colder than average, it was not so extreme that the grid should have run out of available capacity,” it said. “Long start-up times prevent resources from showing up for the grid when New England needs them most.”
Loads peaked at more than 17,500 MW, far lower than winter peak loads from ISO-NE’s long-term load forecast, according to the report.
ISO-NE said Jan. 12 that 17,500 MW is a “typical winter peak.” Some generators experienced “unanticipated issues” that caused them to go offline or reduce their output, ISO-NE said. “These outages were caused by cold temperatures or mechanical problems, and not due to inadequate fuel supplies,” the grid operator said.
The Synapse Energy Economics report said the problem was that thousands of megawatts of generation and imports became unavailable during the day and too many of the remaining resources that were theoretically available would have taken too long to start up to respond in time.
