U.S. grid ready for winter, NERC says, New England and California may face fuel pinch
Energize Weekly, December 1, 2021
Winter electricity-generating resources across the North American grid are forecast to be adequate, although weather and fuel access issues may create challenges for New England, California and parts of Canada.
Those regions were highlighted by the North American Electric Reliability Corp. (NERC) in its annual winter reliability assessment.
Texas, the scene of a major grid failure last February as frigid temperatures caused both fuel and generation failures that led to blackouts, should have adequate resources for the coming winter, NERC said.
The grid operator, the Electric Reliability Council of Texas (ERCOT), “anticipates no reliability issues for the upcoming winter season and should have sufficient generation resources available to meet system-wide peak demand,” the report said.
Utilities and energy developers are projected to add 5,424 megawatts (MW) of natural gas, wind and solar capacity to the ERCOT system by the start of the winter season, bringing total winter capacity to 84,861 MW.
However, a review by NERC and the Federal Energy Regulatory Commission (FERC) of the grid failures last winter found weak spots in the grids in Texas and South Central U.S. that still need to be addressed.
The two regions facing potential fuel supply challenges, according to the winter assessment, are New England and California.
“New England generation continues to be limited by the availability of natural gas,” the NERC report said.
While under most winter scenarios, even abnormally cold conditions, the grid can meet demand, the assessment said, “under a more severe and prolonged winter event— similar to what was observed in January 2018—limited oil inventories can lead to the eventual loss of generation and firm load shed.”
In California and the Southwest, natural gas-fired generation capacity provides more than 60 percent of the capacity to meet on-peak demand, but the region has limited natural gas storage and lacks backup supply chain infrastructure.
“As a result, electric generators face risk of fuel supply curtailment or disruption from extreme events that impact natural gas supplies,” the report said. Examples of the risks are natural gas pipeline disruption or freezing temperatures at natural gas production wellheads that reduce the flow of natural gas into the area.
Weather remains the wild card in the winter projections.
“Extreme winter weather can challenge system operators and limit the availability of resources (e.g., wind generation blade icing, frozen coal piles, curtailment of natural gas pipelines),” the report said.
“Harsh conditions characterized by extreme or prolonged cold temperatures over a large area of North America, such as those experienced during the cold snaps in January 2018 and 2019, create special challenges in maintaining grid reliability in many parts of the North American BPS [Bulk Power System].”
One result of widespread and prolonged periods of cold temperatures can be the reduced availability of capacity or energy transfers – a key backup mechanism for maintaining reliability – and that in turn can lead to operating shortfalls for a grid.
Grid operators in the Canadian Maritime provinces and Quebec “anticipate that electricity imports would be needed to meet extreme peak demands,” the report said. A portion of the Southeast U.S. may also need rely on imports.
In January 2018, for example, extreme winter weather in South Central U.S. led to season-high loads and increase in generator outages over a nine-state area.
The grid operator – the Midcontinent Independent System Operation (MISO) – required transfer assistance using neighboring systems to assist with generation shortages in portions of its system.
Texas’ ERCOT grid, however, has limited links to other regional grids, and when a severe winter storm hit the state in February 2021, importing electricity wasn’t an option.
An arctic front moved through Texas and South Central U.S. and roiled natural gas supplies and electricity generation between Feb. 8 and Feb. 16.
There was a loss of 61,800 MW of generation with 1,045 generating units experiencing 4,124 outages, derates [or operating at less than full capacity] and failures to start. As wellheads and pipeline compressors froze, natural gas daily production in Texas, Oklahoma and Louisiana dropped by 50 percent or 20 billion cubic feet a day.
The NERC-FERC report found that even though there had been “multiple prior recommendations” by the two agencies, dozens of generating units had not developed weatherization plans.
In its recommendations, the report said some operators must still identify and protect cold-weather-critical components and develop corrective action plans for units that experience freeze-related outages.
“This is a wake-up call for all of us,” FERC Chairman Richard Glick said in a statement when the report was released. “We can’t allow this to happen again. This time, we must take these recommendations seriously, and act decisively, to ensure the bulk power system doesn’t fail the next time extreme weather hits.”