'Routine black swans' | North American grids face heightened risk of extreme weather

As more than 90% of US defence sites rely on private power, reliability is also a national security issue

Group silhouette of transmission towers (power tower, electricity pylon, steel lattice tower) at sunset in Humble, Texas, US.
Group silhouette of transmission towers (power tower, electricity pylon, steel lattice tower) at sunset in Humble, Texas, US.Foto: Trong Nguyen/Shutterstock

More of the North American grid is now at risk of failure during severe winter storms than in the past due to rising demand, insufficient generation, and inter-regional connectivity, but also increasing severity of winter storms, according to a report by North American Electric Reliability Corporation (NERC).

The areas at risk extend over much of the eastern two-thirds of the continent, “a much bigger area than we've seen in the past,” said Mark Olson, manager of reliability at NERC.

“Even though nearly all of the areas we have set have adequate resources for a normal winter peak demand, the risk from a prolonged wide area cold snap is very challenging,” Olson added, speaking during a webinar hosted by the American Council on Renewable Energy (Acore) Tuesday.

The report, 2023-2024 Winter Reliability Assessment, was released by NERC to help policy makers and regional transmission operators plan for future demand needs.

“These black swan events are a little bit more routine because it's now just about every season, whether it's winter or summer that we have these prolonged events and we have areas that are really stretched in terms of being able to meet peak demand,” said Thomas Coleman, executive director of grid security project at consultancy SAFE.

These risks have been on full display over the past few years as winter storms Uri in 2021 and Elliott in 2022 left wide swathes of the country without power, resulting in hundreds of deaths and damaged infrastructure. Last summer’s heat wave likewise pushed grids in Texas and US Southwest to the brink.

National security concerns

Risks of grid failure are also a national security issue, as over 90% of Department of Defence (DoD) installations rely on the private sector for power.

As Winter Storm Uri slammed Texas, it knocked out power at 12 of the 15 primary military installations within the ERCOT grid. One Texas military base paid $30m in power prices during the several days of the incident, more than its entire annual electricity bill.

“In the modern threat environment, critical infrastructure is very much on the battlefield,” said Jonathon Monken, principal at research consultancy Converge Strategies and a veteran of the US Army.

“The planning processes that we have, certainly at the bulk electric system level, do not take DoD or national security loads into account,” said Monken.

Grid operators need to ensure that critical customers such as the military are “getting the levels of reliability resilience that they need,” Monken added.

HVDC bolsters grid

Transmission, especially high voltage direct current (HVDC) that can carry bulk power across regions can be a significant reliability asset, said Elise Caplan, vice president of regulatory affairs at Acore.

Inter-regional transmission “can really capture the variation in resource output, the variation in consumer demand and that can be both from renewable energy but also conventional resources that may be experiencing for example, difficulty accessing fuel supplies in one region and not in another,” said Caplan.

Tying reliability to defence, Missouri recently issued its approval of Invenergy’s 800-mile (1,287km) HVDC Grain Belt Express, the first time ever that I'm aware of that national security was specifically cited as a reason,” said Monken.

While much of the US East is at risk, added wind and strong hydropower resources in the Midwest and West have alleviated winter reliability concerns, NERC's report said.

Texas has made substantial improvements in generator readiness and operating reserves, but strong load growth has undermined these advances and the Lone Star state remains at risk of “having insufficient dispatchable resources and generation in wintertime,” said NERC.

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Published 5 December 2023, 22:52Updated 6 December 2023, 14:08
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