When a distribution transformer blows in a neighborhood today, the replacement may not arrive for two years. When a heat wave pushes air conditioning demand past what the grid can deliver, operators have one last tool: cutting power to some customers so the rest don’t lose it, too. This summer, both problems are converging across five major U.S. electricity regions, raising the odds that millions of households could face controlled, rolling blackouts during the hottest weeks of the year.
The Federal Energy Regulatory Commission’s 2025 Summer Assessment, the most recent federal reliability outlook available heading into summer 2026, flagged five grid territories where generation capacity may not keep pace with peak demand: NPCC-New England (the six northeastern states), MISO (much of the Midwest and parts of the South), ERCOT (the independent Texas grid), SPP (the central Great Plains), and PJM (the nation’s largest interconnection, stretching from the mid-Atlantic into the Midwest). Together, these regions serve well over 150 million people.
Why the grid is stretched thin
FERC’s assessment traces the risk to several forces hitting at once. Electricity demand is climbing as data centers, electric vehicles, and building electrification add load that did not exist a decade ago. At the same time, conventional coal and gas generators continue to retire faster than new firm capacity comes online. Wind and solar installations are growing, but their output drops during the calm, hazy conditions that often accompany the worst heat waves, precisely when demand peaks.
Wildfires compound the problem. Smoke can suppress solar generation across wide areas, and fires regularly knock out the high-voltage transmission lines that let neighboring regions share emergency power. FERC specifically noted that wildfire activity could disrupt inter-regional power transfers, a scenario that played out repeatedly during recent western fire seasons when utilities had to de-energize lines preemptively.
In Texas, the stakes are amplified by ERCOT’s near-isolation from the two major national grids. Unlike utilities in PJM or MISO, Texas operators cannot easily import large volumes of emergency electricity from neighbors when local supply falls short. That structural limitation leaves ERCOT with a thinner margin for error during sustained heat. In the Midwest and Great Plains, long transmission corridors and heavy dependence on wind generation mean that a multi-day lull in wind speeds can tighten supply fast, especially if extreme heat is driving demand at the same time.
The transformer bottleneck
Underneath the generation crunch sits an equipment crisis that has been building for years. Distribution transformers, the gray canisters on utility poles and green boxes in suburban yards that step high-voltage power down to household levels, have become one of the hardest pieces of grid hardware to procure.
The U.S. Department of Energy’s supply chain analysis documented lead times ballooning from three to six months before the pandemic to 12 to 30 months by 2023. Industry groups, including the American Public Power Association, have reported that unit costs have roughly quadrupled over the same period, driven by a global shortage of grain-oriented electrical steel, limited domestic manufacturing capacity, and surging worldwide demand as countries electrify transportation and heating. No single federal price index tracks transformer costs with precision, but the quadrupling estimate is consistent across multiple utility surveys and trade publications.
A separate report prepared by the National Renewable Energy Laboratory for DOE examined the age profile of the nation’s installed transformer fleet and the demand drivers that will shape replacement needs going forward. The findings are sobering: many units already in service have exceeded 40 years, well past their designed lifespan. Meanwhile, the forces requiring new transformers, from EV charger installations to data center construction to new solar and wind farm interconnections, show no sign of slowing. The shortage is not a temporary supply-chain hiccup. It is a structural mismatch between what the grid needs and what manufacturers can produce.
In 2022, the Biden administration invoked the Defense Production Act to accelerate transformer manufacturing, and federal funding has since flowed toward expanding domestic production. But building new factory capacity takes years, and utilities heading into summer 2026 are still competing for limited inventory. Many have resorted to refurbishing old units that would previously have been scrapped, cannibalizing parts from decommissioned equipment, and delaying non-critical upgrade projects to preserve stock for emergencies.
What a controlled blackout actually means
When grid operators like ERCOT or MISO declare an energy emergency, the sequence typically starts with voluntary conservation appeals and activation of demand-response programs that pay large commercial and industrial customers to curtail usage. If those steps are not enough, operators order utilities to shed load in rotating blocks, cutting power to sections of the grid for periods that usually range from 15 minutes to a few hours before rotating to another area. The goal is to prevent a cascading, uncontrolled blackout that could leave entire regions dark for days.
Critical facilities like hospitals, water treatment plants, and emergency services are generally on protected circuits and are the last to be cut. But residential customers, small businesses, and traffic signals in affected blocks go dark without individual warning. For people who depend on powered medical equipment, refrigerated medication, or air conditioning to manage heat-sensitive health conditions, even a short outage during a heat wave can become dangerous.
What could change the outlook
Weather remains the single biggest variable. Seasonal forecasts from the National Centers for Environmental Prediction point toward above-average temperatures across much of the continental U.S. this summer. If those projections verify, electricity demand in the five flagged regions could exceed the planning assumptions grid operators used when scheduling generation. But temperature forecasts are probabilistic, not deterministic. A cooler-than-expected stretch in any region would significantly reduce the chance of emergency conditions.
The timing and severity of wildfire season, the location of major storms, and the pace of unplanned generator outages will also shape how close any region comes to its breaking point. ERCOT, for its part, has added battery storage and tightened market rules since the catastrophic failures of Winter Storm Uri in 2021, changes that have improved its reserve margins. Whether those improvements are enough to handle a worst-case summer heat event remains untested at scale.
Federal policy responses, including new efficiency standards for transformers, manufacturing incentives, and grid resilience grants, are in various stages of implementation. But rulemakings and factory construction operate on timelines measured in years, not weeks. For summer 2026, the practical impact of those longer-term investments will be limited.
What households and businesses can do now
For people living in the five flagged regions, the most effective short-term steps are straightforward. Signing up for local utility alerts ensures advance notice when grid conditions tighten. Reducing electricity use during peak afternoon and early evening hours, typically 3 p.m. to 7 p.m., directly lowers the strain on the system when it matters most. Pre-cooling homes in the morning, running major appliances before or after peak hours, and setting thermostats a few degrees higher during demand spikes can collectively shave enough load to prevent an emergency from tipping into a blackout order.
Basic outage preparedness also matters more than usual this year: charged backup batteries for medical devices, a supply of water and non-perishable food, flashlights, and a plan for reaching a cooled public space if power goes out during extreme heat. None of these steps guarantee uninterrupted service, but in a summer when federal regulators are publicly warning that the grid is running closer to its limits than normal, they represent a reasonable hedge against a risk that is no longer hypothetical.
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*This article was researched with the help of AI, with human editors creating the final content.
