A major blackout in 1965 left over 30 million Americans and Canadians in the dark in the northeast for days if not longer. Following the usual postmortem inquiries of what went wrong, why and who to blame, the electric power industry proposed to essentially self-regulate the reliability of North America’s high voltage grid. This led to the formation of the North American Electric Reliability Council or NERC in 1968, which later changed the “council” to “corporation” leaving the NERC acronym unchanged. It has done a reasonable job ever since, but portions of the grid occasionally experience embarrassing blackouts, which can easily cascade to neighboring regions. Obviously, there is always more that can be done to improve the grid’s performance and resilience yet 100% reliability 100% of the time everywhere is more than anyone can expect or afford.
Speaking at an industry gathering in mid 2024, NERC’s CEO Jim Robb, outlined a few issues that keep him up at night. One can suspect that similar issues are on the minds of all grid operators and utility CEOs everywhere and these not unique to North America.
As Robb sees it, the main challenges facing the industry stem from a rapidly changing generation resource mix which requires us to “… rethink a lot of things,” noting that,
“Historical planning approaches are not as effective as they once were, as weather has become more extreme. Physical and cyber-attacks are on the rise, while generation retirements are threatening reliability. Utilities see electricity demand rising for the first time in years.”
Robb highlighted several challenges that probably have parallels in other parts of the world. First on his list is what many believe to be too fast a pace in retiring old and inefficient thermal generation units, particularly polluting coal-fired plants. The UK, for example, closed its last remaining coal-fired plant last year. The lights have stayed on so far. The same is happening across the rich world in the US, Europe, Australia and elsewhere to the delight of the environmentalists.
Robb says the scheduled retirement of some 83 GW of fossil fuel and nuclear generation over the next decade may lead to higher risks of shortages – or blackouts – in certain vulnerable parts of the US. Every year, NERC updates its Long-term Reliability Assessment (LTRA) in which it identifies where supplies may be inadequate to meet the demand as global warming increases demand for cooling during the summer months and especially as extreme weather events become more extreme, more frequent and longer lasting. Extreme weather makes historical trends and traditional forecasts less reliable.
These concerns are amplified by the projected rise in electricity demand from data centers which some expect to double by 2030 consuming as much as 9% of US demand according to the Electric Power Research Institute (EPRI) as noted in the preceding article.
NERC’s long term reliability assessment highlights grid vulnerabilities
Source: 2024 Long term reliability assessment, NERC, Dec 2024
A second area of concern is the fact that some 2 TW of mostly renewable or hybrid capacity is currently stuck in interconnection queues, waiting to be connected to the high voltage transmission network. Robb notes that the amount of capacity in the interconnection queues are “now twice the size of the existing resource base of the country.”
While nobody is happy about the current 2-to-1 ratio, the aggregate capacity in the interconnection queues has historically been about half to a third of the installed base. It suggests that there is a high level of interest in developing new generation resources, particularly renewables and storage, but also natural gas-fired plants. There is no question that investment in transmission networks has lagged generation in recent years.
The third issue – not a concern per se – is that the rapid transition to a renewables-heavy resource mix will require more natural gas generation and greater coordination between the gas and electric systems – which historically evolved and operated independently. Robb says, “It’s not that I love natural gas so much, but I really love natural gas generation,” highlighting its “ability to operate reliably and flexibly on a dispatchable basis.” This becomes even more critical as more variable solar and wind resources are added to grids across the US and elsewhere.
“We need to be paying close attention to securing the balancing resources to integrate variable resources reliably.”
Acknowledging the growing role of storage and hydrogen in the “long term” Robb says currently we must rely on natural gas to complement variable wind and solar generation.
“That means the gas and electric systems must work in tandem.”
He has a valid point, The two systems historically evolved in parallel, but the time has arrived to link them together. Currently the utility sector accounts for roughly 40% of US gas consumption. Until long duration storage, hydrogen and other approaches to firming the variability of renewables become feasible and cost-effective natural gas must make up for the variability of renewables.
NERC flagging grid vulnerabilities across the North American continent
Source: 2024 Long term reliability assessment, NERC, Dec 2024
Like everyone else, NERC is paranoid about the threats posed by cyber security, “driven by the fact that we have software embedded everywhere [but] we rarely know exactly where the coding came from.” Robb points out that the National Institute of Standards and Technology (NIST) publishes a list of grid cyber vulnerabilities averaging about 60 entries per day.
Finally, NERC, at the request of the US Congress, has examined the interregional transfer capabilities of the high voltage grid in a study delivered to the Federal Energy Regulatory Commission (FERC) in December 2024 and is expected to release the results of its analysis in the first quarter of 2025 on the interregional transfer capabilities of the grid connecting the US and Canada as well as between Canadian provinces, which are poorly connected. Many Canadian provinces are better integrated to the US than amongst themselves. A casual look at the Canadian high voltage transmission network shows more lines going north to south rather than east to west.
Given the issues highlighted above, interregional linkages are becoming even more pressing in the future than they have been in the past.
NERC is focused on increased interregional transfer capabilities
Source: 2024 Long term reliability assessment, NERC, Dec 2024
The challenges highlighted by NERC may be found on the priority lists of other grid operators and coordinators in Europe, Australia and anywhere else with large interconnected high transmission networks.
Being paranoid and vigilant is a necessity if your responsibility is to maintain a reliable grid. The more executives like Jim Robb stay awake at night worrying about such issues, the better the rest of us can sleep knowing that the lights will come on whenever we flick the switch.
This article originally appeared in the February 2025 issue of EEnergy Informer, a monthly newsletter edited by Fereidoon Sioshansi who may be reached at [email protected]"