North American power grid faced extreme weather and cyberattack risks in 2021
Energize Weekly, July 27, 2022
The North American electric grid faced unprecedented challenges from severe weather, cyberattacks and problems with natural gas supplies in 2021, but with except one exception – in Texas – utilities and grid operators were able maintain reliability, according to the North American Electric Reliability Corporation (NERC).
“Throughout 2021, the North American electricity industry continued to weather cyber and physical attacks of varying degrees of sophistication and severity,” NERC said in its 2022 reliability assessment.
The most high-profile reliability challenge came in February 2021 when a sustained cold spell hit Texas. As generating units failed and there was difficulty obtaining natural gas, the grid operator was forced to issue rolling blackouts.
It was the third largest controlled load shed event in U.S. history, NERC said, following the 2003 Northeast blackout and Western Interconnection blackouts in 1996.
At least 210 deaths were directly or indirectly connected to the February 2021 cold weather outages along with an estimated loss to the Texas economy of between $80 and $130 billion.
“The impact of wide-area and long-duration extreme weather events, like the February 2021 South Central U.S. cold weather event and the August 2020 Western U.S. wide-area heat event, have underscored the need to consider extreme scenarios in resource adequacy and energy sufficiency planning,” NERC said.
Utility planning has focused on meeting projected peak demand, which had been seen as the prime risk, but NERC said that is no longer the only peril as the Texas combination of extreme weather and disputed fuel supplies showed.
The share of natural gas-fired generation has grown by 250 percent in the last 30 years and in 2021, accounted for 43 percent of the country’s generating capacity.
“With the continued retirement of coal and nuclear units and a growing reliance on natural gas-fired generation, the interdependency of the electricity and natural gas industries has become more pronounced,” NERC said.
During the Texas winter freeze, natural gas wells, compressor stations and pipelines were also hurt by the cold weather, limiting fuel supplies.
“It is now evident that these risks are no longer emerging; they are certain and expected to increase,” the agency said. “Natural gas-fired generators are now necessary balancing resources for reliable integration of the growing fleet of variable renewable energy resources and can be expected to remain so until new storage technologies are fully developed and deployed at scale to provide balancing.”
In addition to cold and heat, wildfire and hurricanes also posed threats to power system. Hurricane Ida, which hit Louisiana in August 2021 led to 210 transmission lines out of service and 1.2 million customers without power.
“While most wildfire impacts on the electricity system are at the distribution level, wildfires also pose a risk to the reliable operation,” NERC said. “These risks arise through damage to transmission infrastructure and through preemptive public safety power shutoffs.”
In 2021, there was at least one case where a wildfire – the Bootleg Fire in Oregon – led to a five-hour blackout when three 500-kilovolt lines were tripped.
Cyber and physical security threats were also challenges for grid operators and utilities in 2021.
“The North American electricity industry continued to weather cyber and physical attacks of varying degrees of sophistication and severity,” NERC said. “Notably, cyber-attacks routinely targeted the digital supply chain.”
In addition to digital supply chain attacks, there were increased reports of suspicious cyber incidents – including vulnerability exposure, phishing, malware, denial of service and other cyber-related assaults.
“Although the reliability of the BES [bulk electric system] was maintained, nation-state adversaries and organized cyber criminals have demonstrated that they have the ability and willingness to disrupt critical infrastructure,” NERC said.