Each region of the United States is facing its own mix of climate-related grid reliability challenges, but arguably the Northeast must deal with the most diverse batch of threats. Summer heat waves can stretch resources, hurricanes destroy grid equipment, wind and winter storms snap power lines, and flooding is a flip-side challenge of undergrounding equipment.   

And the impacts of these threats on utilities are getting more severe.

Take Consolidated Edison (ConEd), for instance, which delivers electricity to more than 3 million customers in New York City and Westchester County. Prior to 2011, no storm had ever caused 200,000 outages on the utility's grid. 

Then came Hurricane Irene in August of 2011, which caused 204,000 outages on ConEd's system. Then a year later, Hurricane Sandy caused 1.1 million outages. In March 2018, the utility experienced winter storms Riley and Quinn, which caused a combined 210,000 outages. And in August 2020, Tropical Storm Isaias caused 330,000 outages.

ConEd is spending billions of dollars to strengthen its system, and earlier this year it published a report laying out how it will incorporate climate change into its planning and operations. Fundamentally, the utility concluded its energy infrastructure is vulnerable and the impacts of climate change on the grid are accelerating. Beginning this year, the company will incorporate projected climate change-driven increases in load, and reductions in power equipment ratings, into load relief plans that look out 10 and 20 years.

"The future is not going to look like the past," Patrick McHugh, ConEd senior vice president of electric operations, said. "The next 20 years is not going to look like the last."

The planning ConEd is doing is essential to maintaining reliable service, said Hector Artze, a partner with Guidehouse's energy, sustainability and infrastructure practice. And it is a process more utilities will soon undertake.

"Utilities need to start paying attention to climate change and how to bring that into their planning for resilience," said Artze. "And they are going to uncover, no doubt, that there will be need for adaptation."

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"[I]n my view as distributed resources start to increase in penetration, that planning process for reliability gets challenging."

Hector Artze

Partner, Guidehouse

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Climate models are a key aspect of utility planning now, said Guidehouse's Artze.

"There are very well researched models out there, climate models that that indicate over time, and very locally, what is the likelihood of certain perils," Artze said. "And they can be modeled from now, for the next 50 or 100 years."

State lawmakers and regulators are increasingly directing utilities to consider the impacts of climate change on their systems, but Artze warned utilities need to plan for it in an integrated fashion. Transmission and distribution planning are often not considered together, he said, which will become a more significant issue as distributed energy resources are added to the system.

"Transmission and distribution planning is highly focused on meeting customer capacity, demand, and maintaining certain levels of reliability," said Artze. "But in my view, as distributed resources start to increase in penetration, that planning process for reliability gets challenging."

As utilities examine climate data and get a clearer picture of what impacts they must mitigate, spending is rising. ConEd spends about $3 billion annually to keep its entire system safe and reliable, said Nelson Yip, director of strategic planning for the utility. Within that, the utility is spending $2 billion over 10 years to address the impacts of intense weather.

Undergrounding power lines not simple or cheap

ConEd's largest system hardening investments came after Hurricane Sandy, when the utility spent $1 billion over four years, and it is now in the midst of investing another $100 million in Westchester County.

"And we continue to get really positive feedback from the regulator and intervenors, to spend more on hardening the overhead system," McHugh said. About 86% of ConEd customers are served by one of 64 underground network systems, which tend to be far more resilient. The remaining electric customers are predominantly served by overhead lines, which are more vulnerable to climate change-related disasters.

ConEd this year launched a pilot program to underground more power lines, a trend among utilities, said McHugh. Florida Power & Light, Pepco in Washington, D.C., and Dominion Energy in Virginia and North Carolina, are taking similar approaches.

It is not always simple, however. ConEd found that customers on Staten Island did not want to have power lines undergrounded because of the disruption the work would create. Cost is another issue.

"It is expensive, but we don't look to underground the entire system," said McHugh. "We think the right approach is going after the areas that have frequent storm damage. And we also have to approach this in an environmental justice way, where lower income areas that can least afford to lose power for long durations would be a higher priority than other areas."

The utility's storm hardening efforts are already paying dividends. Since 2014, ConEd estimates its investments have reduced the number of storm-related customer outages by over 680,000. 

"There will be a cost to build climate resilience," said Yip. "But really, the potential cost of inaction is much higher. ... Undergrounding is a big task for our energy infrastructure, but we have to start somewhere."

Stronger poles, multiple modeling scenarios boost National Grid’s reliability

National Grid delivers electricity and gas to more than 20 million people across New York, Massachusetts and Rhode Island, and is currently working on a study of its system to identify sections that have historically been prone to failure. Across the region, it spends almost $1 billion annually on resilience, said company officials.

"We definitely are looking at resilience and climate impacts. It's a major part of what we are focusing on for the future," said Carol Sedewitz, National Grid's vice president of electric asset management and engineering.

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"We're actually modeling our infrastructure and what the impacts might be under two degree and four degree warming scenarios..."

Carol Sedewitz

Vice President of Electric Asset Management and Engineering, National Grid

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The utility wants to achieve an 80% carbon free electric supply by 2030, but it has begun examining planning scenarios as far out as 2070.

"We're actually modeling our infrastructure and what the impacts might be under two degree and four degree warming scenarios, so that we can then develop long term plans for how we need to change our infrastructure," Sedewitz said. "So do we need to do certain amounts of flood mitigation in the next 20 years? And will that change in the next 30 or 40 years, depending on those two scenarios?"

Like other utilities, National Grid is doing targeted undergrounding, flood mitigation and coastal hardening. The utility is replacing assets that may be half a century old or more, and rebuilding them to more stringent standards. Certain utility poles in its distribution system, for instance, are built closer to transmission standards to ensure durability in extreme weather.

"Any location on our distribution system that is a tie point between circuits, or if it has a recloser or switch on them, we want to make sure that those poles don't come down in any kind of storm," said Sedewitz. National Grid now uses what is essentially a transmission size pole, she said, which is still wood but with a larger circumference, compared to what was used in the past.

"We call them critical locations," Sedewitz said. "These are poles that we think can withstand the more severe weather that we're expecting."

In Massachusetts, that means more frequent and severe "minor storms," said Sedewitz, along with hurricanes tracking up the coast. National Grid is spending $350 million annually in that state to bolster its transmission and distribution system, and close to $1 billion across its upstate New York and New England businesses.

PSEG's flood mitigation efforts keep substations dry

In New Jersey, Public Service Enterprise Group (PSEG) recently announced plans to spend $900 million from 2021-2025 to boost reliability, while the utility's past investments have already paid dividends. More than two dozen substations flooded during Hurricane Sandy and Hurricane Irene, but none flooded in Hurricane Ida this year.

"When Ida came in, we saw great benefits from our previous investments," said Michael Schmid, PSEG's vice president of asset management and centralized services. The utility rebuilt substations and raised assets above flood lines, added reclosures to limit outages in the event of a disruption, and is collecting climate studies to compare with its own historical data to better understand future system needs. 

PSEG sees flooding, hurricane winds and extreme heat as threats to its system, and load flow studies account for rising demand as temperatures rise and vehicle electrification takes hold. 

The utility's reliability investment will grow its overall 2021-2025 capital spending plan by almost a billion dollars, to the $14 billion to $16 billion range. And in September, PSEG filed an Infrastructure Advancement Plan with regulators that calls for improvements to last-mile reliability along with electric vehicle infrastructure and modernizing electric substations.

"As you start upgrading that last mile investment, you're doing two things," Schmid said. "You're making it more reliable for the customer on a blue sky, normal day ... but you're also preparing for storm events, or any kind of climate change.

Cost is an issue, as it is for all utilities, said Schmid. The key is in planning.

"There are going to be incremental costs," he said. "So you have to make sure that you have the best available data in front of you, to estimate when you should be making the system improvements. But you don't want to do them too early and you don't want to make too large of an investment. You want to be just in time, or just ahead of the curve."