Last week, as temperatures plunged and energy consumption soared, electric customers in the country’s southeast were urged to turn off the lights and unplug appliances to avert potential blackouts.
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In Connecticut and across New England, where talk of electricity tends to turn on highest-in-the-nation rates, the potential cold weather energy emergency faced by customers elsewhere was averted, but that success comes with a warning.
Consumption peaked across the region and the energy grid underwent an extreme weather stress test as homes and businesses dialed up thermostats against historic cold. What kept electricity flowing across all six states were the old school, oil-burning, electric generation plants now under pressure for closure under aggressive state decarbonization targets.
Data produced by ISO New England, which manages the regional power grid and succeeded last month in keeping it energized, show that the percentage of electricity produced by oil-fired power generating plants shot up during the coldest days of late January, far exceeding the region’s predominant power source, natural gas.
At the same time, energy produced from renewables was near the bottom of the graph.
On cold days from January 24 to 28, the ISO data shows oil-generated power significantly exceeded that produced by natural gas and at times approached the maximum capacity of the region’s oil generators of around 8,000 megawatts. During the snowy morning of January 25, oil was responsible for the greatest percentage of ISO’s power production, at 7,753 megawatts, while natural gas was at 6,036 megawatts.
Oil-powered electric generators in Middletown and Milford called “peakers” and operated by GenCon, were dispatched or called into service by ISO and ended up running more during the month of January than the entirety of the previous year, according to operator Devang Patel.
Nuclear power purchased under contract from the Millstone and Seabrook power stations in Connecticut and New Hampshire remained constant through the period at around 3,300 megawatts. Renewables produced fewer than 2,000 megawatts. At one point, New England was getting more energy from burning wood and trash than it was from wind.
Analysts gave the New England power grid high marks for getting through what ISO has called “a complex array of challenges” and avoiding the imminent prospect of below freezing blackouts or brown outs that developed elsewhere
“Over the past two weeks, New England’s power system experienced its most challenging operating conditions since the winter of 2017/2018,” ISO said. “Prolonged cold temperatures drove consumer demand for electricity sharply upward, both at peak moments and in overall usage, placing sustained pressure on the power system.”
A pedestrian bundles up against the cold while walking along a shoveled path in Bushnell Park in Hartford, Wednesday, Jan. 28, 2026. (Aaron Flaum/Hartford Courant)
Looking ahead, pressure on the grid is expected to increase. There will be periodic jumps in power usage resulting from extreme winter and summer weather. But those spikes will be exaggerated by the power drain from expanding technologies like artificial intelligence and by government decarbonization policies such as those that promote electric vehicle use and electric home heating systems.
In the short term, ISO is planning for another stretch of unusual cold starting this weekend and, to meet it, has applied for an extension from the federal government of an environmental waiver to permit the continued operation of oil fired generators.
Over a longer period there is concern among groups outside of ISO over pressure in energy under-served places like New England to shut down so-called dirty generators that fill in the gaps during emergencies before they can be replaced by equivalent alternatives.
In its January 2026 Long-Term Reliability Assessment, the nonprofit North American Electric Reliability Corp, reports that New England ranks higher in energy supply reliability during extreme weather conditions than most of the country. The risk of failure is rated “elevated” in New England compared to “high” in parts of the mid Atlantic, mid West, Northwest and Texas.
But the assessment also warns of cold weather supply shortages everywhere based on the current movement toward replacing existing oil and gas electric generation with “weather dependent” renewables.
“The continuing shift in the resource mix toward weather-dependent resources and less fuel diversity increases risks of supply shortfalls during winter months,” NERC reports.
The regional trade group New England Power Generators Association is concerned that there is nothing currently available adequate to replace oil burning generation.
“The state laws and aspirations on clean energy development and emissions trajectory are not matching the reality of the physics on the grid today,” President Dan Dolan said. “We are still heavily reliant on traditional fossil fuel energy to meet a lot of these peaking needs. I think that is a challenging political message, but a really important one that we have seen play out over the last couple of weeks.
“A second subject with less sizzle — though I think equally important — is that this system works and works well. We did not have any reliability events despite arctic temperature and the coldest winter in nearly 10 years across New England.”
The cold keeps coming: Part of CT under dangerous, extreme cold watch for weekend
Connecticut’s energy picture is clouded by its inability to get an adequate supply of natural gas, the main source of energy in the state and wider region. Gas is cheaper than oil under all but extreme market conditions and cleaner to burn from an environmental perspective. Many in the energy industry consider it an effective means of generation during a transition to cost-effective renewable technologies or the across decades it will take to build a clean, nuclear generating plant.
The Marcellus Shale in Pennsylvania is one of the world’s most productive gas fields. But opposition from environmentalists, who consider gas little better than oil as a pollutant, have so far blocked completion of a pipeline that would carry gas through New York and into Connecticut and New England.
Should a pipeline be completed, it could save New Englanders $1 billion annually in energy costs and help eliminate the need to augment the region’s energy supply by burning oil during both extreme weather events and as demand on the grid grows.
A CT DOT snowplow travels along Washington Street in Middletown as snow falls Sunday, Jan. 25, 2026. (Aaron Flaum/Hartford Courant)
During the winter heating season, New England’s limited gas supply is allocated by priority. At the front of the line are homeowners and businesses who need it for heat. What is left, is distributed to power generators who use it to run turbines. When there is not enough gas to run the turbines, the price spikes and ISO dispatches the oil burning generators.
“I think more gas infrastructure is something that the region should have a conversation about,” said Pat Smith, Eversource vice president for energy supply. “If we had more gas infrastructure feeding New England, prices would have been lower, potentially much lower. And we would have been running less oil. And obviously oil comes at a higher emissions rate.”
