In Summer Of Record Heat, U.S. Power Grid Is Holding Up–So Far

Despite earlier warnings from grid operators and power grid reliability experts, this summer’s unprecedented heat waves have not caused rolling blackouts in the U.S.—at least not so far.

While residents in several states, including Texas, Indiana, Illinois and Iowa, have been encouraged to reduce their energy consumption during peak hours to avoid rolling blackouts, few have had to endure them at this stage.

Residents of Grosse Pointe, Michigan, just north of Detroit, lost power late July because of a transmission outage. DTE Energy’sDTE
vice president of distribution operations told the local ABC-affiliate that the outage may have been caused by aging infrastructure but that “certainly, the high temperatures could have played a part.” Elsewhere, residents of New York City and central California faced outages caused by the heat.

Most blackouts are still the result of a local event, like a car running into a utility pole, according to professor Jay Apt, co-director of the Carnegie Mellon Electricity Industry Center. “Very few outages are caused by insufficient power generation and transmission lines failing…the biggest single cause is storms that will blow a tree into an electrical line,” he said.

“In general, I’d say the grid has held up fine, but it’s very early in the summer,” North American ElectricAEP
Reliability Corporation (NERC) CEO and President Jim Robb said on the Public Power Now podcast in July. “The real strain period for the grid is going to come in August and early September, particularly in the west. So I would by no means say that we’re out of the woods, but so far, the grid operators have been able to arrange their generation fleets to be able to meet the demand that they’ve seen.”

An assessment by NERC in May found that the Electric Reliability Council of Texas, all of the 14 U.S. states under the Western Electricity Coordinating Council and the central U.S. states under the Southwest Power Pool were at elevated seasonal risk — meaning they faced the “potential for insufficient operating reserves in above-normal [weather] conditions.” The Midcontinent Independent System Operator — which manages generation and transmission of power across 15 states including Illinois and Michigan — was at “high risk” and could face “potential for insufficient operating reserves in normal peak conditions.”

Robb told Forbes in a statement that this summer’s assessment “is among the most sobering NERC has published to date.”

“Since 2018, we’ve seen an increasing number of risks to bulk power system reliability that are occurring at an accelerating rate,” Robb said. “As the grid undergoes fundamental transformation, managing the pace of change is the central challenge for assuring reliability and resilience to increasingly frequent and extreme events.”

Predicted high temperatures and drought was a large factor in NERC’s grim outlook, with the National Weather Service in May saying the probability of nearly all of the U.S. experiencing above-normal temperatures this summer was “leaning” or “likely” above normal. The NWS also found that most of the Northwest, most of the central U.S. and most of Texas were facing “leaning below” and “likely below” normal levels of precipitation.

The weather forecasts have proved true: most of the West and Southwest are experiencing droughts and several cities across the country have recorded record temperatures.

That kind of weather “does something on the demand side [and] it does something on the supply side,” according to Apt. Increased demand from a heatwave is usually manageable for the first few days through demand response programs, which allow institutions and companies to earn revenue by reducing their power usage during peak periods. But the effectiveness of those programs peters out after a few days because of “demand response fatigue.” In other words, after a few days, businesses tire of mapping out their energy consumption ahead of time.

However, the bigger implication on the grid from high heat and low rainfall is not the increased demand, but lowered capability. Hydroelectricity is reduced when less water is available and “when you have an extreme hot day, you’ve got limitations on coal plants and on natural gas plants,” Apt says. “The air that supplies the oxygen for the combustion is less dense when it’s 100 degrees out than when it’s 20 degrees out. And so the natural gas plants…have to reduce their output because they’re not getting so many atoms of oxygen as they are when it’s colder out. With a coal plant, the cooling water that cools the big tea kettle, the coal plant, isn’t as cool as it was. So they’ve got to back off their output in order to not melt their equipment.” The same is true for many nuclear plants not positioned near the ocean.

While the worst case scenario of nationwide blackouts and brownouts caused by heat has not come to fruition, lawmakers and officials have heeded utilities’ dire warnings and have pushed for grid modernization and increased reliability in a number of ways.

Rep. Jerry McNerney (D-Calif.), a member of the House Committee on Energy and Commerce, said that the power crisis in Texas in February 2021 in which at least 200 people died made several lawmakers realize grid reliability is an “initiative we all need to worry about.”

McNerney introduced the Grid Resilience Act in July, which would require the federal government to conduct a study about the need for and feasibility of standards that would ensure thermoelectric power plants are able to operate during droughts. It passed the House as part of the Wildfire Response and Drought Resiliency Act on July 29 with a vote of 218-199. That bill also includes other lawmakers’ legislation to invest in energy storage and microgrids as well as allow regions to share power in case of an energy emergency.

McNerney said that he supports plans to keep the Diablo Canyon nuclear power plant in southern California open. The plant accounts for 9% of the state’s energy production and had been slated to shut down in 2025, but Gov. Gavin Newsom (D) has pushed for the timeline to be extended in the face of rising energy demand.

“With the drought, we’re not only facing wildfires and threats to our grid, but we’re facing less ability to produce hydropower,” McNerney said. “We have extreme events, we can’t make up for that…Keeping Diablo Canyon open makes a lot of sense at this point, at least for a few years. Now, we have issues with regard to nuclear power that I think need to be addressed. But it is a low-carbon energy source and it can produce a lot of power, so we need to be open-minded about how we can produce that power.”

While the Wildfire Response and Drought Resiliency Act still has to make its way through the Senate, it is not the only time Congress has considered grid resiliency measures recently. The Inflation Reduction Act, which passed the Senate on Sunday in a party-line vote and is expected to breeze through the Democrat-controlled House on Friday, contains numerous climate provisions that would support grid reliability, such as subsidies for solar and other renewable energy. And the bipartisan infrastructure deal, signed into law by President Joe Biden, contained numerous provisions related to strengthening power grid infrastructure and managing load.

As part of the infrastructure law, the Department of Energy announced in July a $2.3 billion grant program designed to support state and tribes’ efforts to modernize the grid. The grant program will provide $459 million annually for an expected five-year period across states and tribes to support things like integrating microgrids, adding fire resistant components and undergrounding equipment.

“We need to put as many of the power lines underground as possible, that’s certainly going to make a difference in terms of reliability in wildfires and other key related issues,” McNerney said. Extreme temperatures compromises the stability of power lines and causes, among other structural issues, drooping, he adds.

But McNerney, Apt and other experts are in agreement that $2.3 billion is nowhere near the amount needed to make a real upgrade in the infrastructure. “$2 billion, while helpful, is a drop in the bucket,” says Apt. McNerney similarly noted that that amount would be insufficient to upgrade the grid in California alone, but is hopeful that it could “encourage public-private partnerships and [utilities] to plan ahead and understand what’s going to be needed before that before it’s too late.”

Paul Alvarez, CEO of a distribution grid planning and investment consultancy firm called Wired Group, says some of the strains the grid faces during peak times could be offset with proper energy use management, such as through smart meters. However, he thinks some utilities may be unmotivated to promote smart meters because lowered electricity use would translate into lower profits. “Rather than just always building the system to meet the peak, well shoot, what if we can manage the peak to meet the system? It makes a ton of sense, it should absolutely be able to reduce the number of calls for those rolling blackouts and brownouts and it should absolutely improve our ability to take more solar and wind on the system. But the distribution utilities really don’t have the motivation to do it, so we’re in a little bit of a pickle here.”

With continued investment in the grid, one could expect reliability to improve — but Alvarez and Apt suggested much of the issues surrounding grid modernization will remain unless market incentives and oversight of utilities’ spending improve.

While Alvarez does not oppose certain investments, such as to accommodate wind and solar power, he cautions that utilities are motivated to keep seeking capital, which could lead to excess investment. “We need to have more pushback, we need to have more qualified examination of what the utilities are telling us,” he said, noting that it’s particularly challenging given frequent lack of knowledge from legislators and the small number of qualified experts not working for a utility.

Apt views lack of market incentives as a potential roadblock to improved reliability, noting that companies were not financially motivated to build natural gas plants in the upper midwest after several planned coal plant retirements over the past few years.

“Now this summer, we have a situation where the reserve margins in the upper midwest are pretty skosh, they’re kind of low,” he said. “Until we get adequate price signals to entice other people into the market, that’s a vulnerability, just like the fact that the market didn’t send any signals in Texas to winterize their plants and indeed winterize the natural gas infrastructure. There wasn’t a price reason to do that so people didn’t do it.”

In part because of a lack of market incentives and in part because of climate change, the conversation on grid reliability is far from new — but this summer has brought even more attention to the issue. “We’ve been issuing warnings about the grid for a number of years,” Mark Denzler, chief executive of the Illinois Manufacturers’ Association told the Washington Post. “But the swiftness with which this has happened has caught people by surprise. They didn’t think we would be having these issues for a couple of years.”

While worries expressed earlier this year about grid modernization have somewhat subsided, as the U.S. made it through July without any major reliability issues, the problems prompting the concerns in the first place have lingered. And assuming the grid makes it through the summer intact, winter is just around the corner.