PJM Says the Reprieve of the Milder Seasons Used for Maintenance Is Not What It Used to Be

On October 15, 2026 PJM published an article on its own news site, Inside Lines, under the title "Providing Reliable Electricity in a New Reality." The end of summer and the transition into fall, it begins, "usually offers the electric grid a chance to catch its collective breath and prepare for the challenges to come in the winter season ahead." Parts of the article follow, not the whole.

The Shoulder Seasons

Owners of generators and transmission lines, the article says, use the milder weather of spring and fall, when demand typically moderates, to shut down for needed maintenance or upgrades. PJM has long relied on these "shoulder seasons" to plan and coordinate equipment outages with its member companies, "even with a significant portion of the generation fleet out of service for days or weeks."

"But the once-dependable reprieve is not what it used to be." One reason the article gives is that the profile of PJM's customers is changing. Most of the new, rapidly growing demand "is from data centers and other energy-intensive Large Load customers, and their consumption does not fluctuate significantly with the weather; it is a 12-month 24/7 phenomenon."

That expanding demand is outpacing new transmission and supply, PJM writes, and unseasonably hot or cold weather now arrives early and stays late. The result is that "periods the grid once relied on for maintenance and preparation can now become periods of significant system stress and reliability risk."

A plant still needs its outage, and a line still needs its upgrade. What the article describes is the season for that work meeting a load that runs around the clock, all year.

A Prime Example

The week the article was written, it says, "has been a prime example." It puts the generation outages at "about more than 61,000 MW," and says PJM was working with only 66% of its generating fleet's capacity. The outages were spread across all kinds of resources, from nuclear, coal and gas to wind, solar and hydro.

More than two-thirds of them were for planned maintenance or construction. About 15,000 MW were unplanned, according to preliminary data. PJM worked with member companies to recall about 10,000 MW "to get to that 61,000 MW number." Canceling more, it says, would risk those facilities not being able to properly prepare for winter.

On the Tuesday and Wednesday of that week PJM issued a series of emergency procedures, to have enough generation online for temperatures the article calls "unseasonably warm, but not extreme." The Energy Department, it says, "for the ninth time this year, issued an order to allow PJM to direct backup generation at data centers and other Large Load electricity customers to operate to avoid outages to other customers." PJM "did not use that authority and has not done so to date," and calls it a valuable tool to help protect regular customers.

An authority that has not been used is still an authority. For a campus, the question is what its backup plant is permitted, and fueled, to do on the day it is.

A New Reality

The emergency procedures and the Energy Department's orders are important tools, PJM writes, "but they alone may not be enough." Equipment outages will continue to be necessary in the shoulder seasons to build critical transmission projects. Much of the new construction upgrades or replaces existing lines, to bring energy into areas where generators are retiring and to serve load that is growing across PJM's footprint, "because Large Loads are not confined to one area." Building new generation it calls critical.

To that end, PJM says it has reformed and streamlined the engineering process for new generation to connect to the grid. It has "opened a process to match new Large Load customers with new supply resources." It has received conditional approval from the federal regulator for a "Reliability Backstop Procurement" process to secure more generation in the short term. And it has opened an accelerated process to connect large, state-sponsored projects.

PJM has also sharpened its forecasting, the article says, to understand "just how much proposed Large Load demand is likely to materialize and when, in addition to the approximately 11,000 MW of data center load already on the system."

Readers "may notice the extra activity and emergency procedures," the article says, until the necessary generation and transmission "can be placed in-service, which is not expected to occur in the immediate future."