PJM Interconnection: 2025 Year In Review Part I - Operations Improvement See Regional Electric Grid Through Record Peaks, Growing Demand

This is the first in a series of three articles from the PJM Interconnection covering the top events, developments and trends impacting PJM's Operations, Markets and Planning in 2025.

PJM maintained reliability through peak weather conditions amid growing demand and tightening reserve margins.

As 2025 began, PJM’s generation and transmission fleet supported reliable operations and notched new winter demand records during a week-long January freeze. 

An Arctic Outbreak that started on Jan. 18 brought single-digit temperatures to much of PJM and neighboring grids.

By Jan. 22, PJM demand swelled to an hourly peak of approximately 143,700 MW between 8 a.m. and 9 a.m. At the same time, PJM kept exporting 8,000 MW to support surrounding grid stability. 

That successful performance surpassed PJM’s prior all-time cold season record of 143,400 MW peak set in 2015.

PJM also served its fifth highest and sixth highest winter loads on Jan. 21 and Jan. 23, the last of the six-day event.

PJM’s reliable operations were made possible by improved preparations for wintry weather and notable collaboration between PJM and member companies. 

Actions taken included generator testing prior to freezing weather, early commitment of gas-fired units, reliable short-term load forecasting, and temporary return-to-service of vital transmission facilities from maintenance or construction outages.

New Winter Preparedness Measures

PJM entered the winter of 2025/2026 with an operational capacity of 180,804 MW, a slight decline in available resources from the year prior but sufficient to meet reliability standards.

In October 2025, new cold weather readiness standards for generators formulated by the North American Reliability Corp. (NERC) became effective. 

NERC oversees reliability for the grid operators in North America on behalf of the Federal Energy Regulatory Commission (FERC).

The new mandatory NERC standards require that generation resources:

-- Implement freeze protection measures and other steps to prepare units for winter [natural gas-fired units in particular].

-- Disclose any operational constraints that impact their operations in freezing weather to dispatching grid authorities [in particular, natural gas-fired units] and submit corrective action plans for such constraints. This information enhances PJM’s existing database of minimum operating temperatures for each of the resources in its generation fleet.

Beyond new mandatory standards, PJM has long required generators to follow a specific mandatory cold weather checklist and is constantly improving winter preparedness. 

Steps like these enhance collaboration with, and readiness of, critically needed generation during extreme cold--

-- For the winter of 2025/2026, PJM planned to double the number of winter preparedness site visits to 30 generator facilities in tandem with staff from ReliabilityFirst.

-- PJM urged generators to self-schedule for testing, particularly when temperatures are forecast to fall below 35 degrees. Leading up to and throughout winter, PJM also conducts unannounced Operational Tests of dispatchable generation units.

-- PJM enhanced the Cold Weather Operating Limit Data Request to better align with NERC Standards for determination of a unit’s minimum operating temperature and startup temperature from a cold state of operation.

-- During critical periods, PJM units will regularly update their dynamic [natural] gas supply availability via a new Markets Gateway data field.

-- PJM continued weekly, and daily as necessary, communication and coordination with [natural] gas pipeline operators to improve situational awareness of possible supply limitations.

Milestone Summer Performance

When temperatures arrived at the other end of the thermometer in summer, PJM kept air conditioners and fans going for the 67 million people in its footprint. 

The early summer heat wave, June 22–June 26, gave rise to PJM’s third- and fourth-highest all-time summer peaks, approximately 162,400 MW and 161,800 MW, respectively, on June 23 and June 24. June 29 peak load of approximately 157,500 was the ninth highest.

While using all generation available, PJM tempered late afternoon electricity demand by calling on customers who receive compensation in exchange for trimming power use. 

Customers like these, enrolled in what is known as load management or demand response programs, participated to ease load during critical periods. 

In all, PJM initiated six load management events last summer.

Major Substation Failure Prompts Coordinated Response To Avert Widespread Outages

PJM Operations’ response to a predawn critical substation outage on Aug. 11 mitigated the risk of up to 1,200 MW load loss around Baltimore. 

As equipment failures multiplied in the dawn hours before the morning peak, PJM implemented emergency procedures in the BGE transmission zone and returned to service some generating units from maintenance outages.

Daylong relief measures included a call on all Demand Response resources in the BGE zone. As studies showed risk of widespread urban outages near the afternoon peak, 

PJM initiated a Load Shed Directive to interrupt approximately 20 MW of system load for 28 minutes.

Solar Additions Highlight Changing Resource Mix

Contributions by solar resources serving PJM energy needs reached an all-time PJM high on April 18 of nearly 12,000 MW. 

This growth in solar output coincided with continuing solar growth in the PJM fleet. In 2025, 2.2 GW of solar generation was added, while PJM also netted 55 MW of new wind and 29 MW of new coal resources.

Preparedness for Peak Conditions and Load Growth

PJM coordination with member generation and transmission owners was enhanced in multiple ways during 2025. Actions included--

-- Expanded Demand Response Availability: PJM expanded its demand response (DR) availability window from limited windows (10 a.m. to 10 p.m. in summer, 6 a.m. to 9 p.m. in winter) to availability 24 hours daily. This change improves grid reliability by including DR resources during all hours of risk and takes effect for the 2027/2028 Delivery Year. 

-- Expanded Transmission Outage Studies: PJM broadened study and coordination of the operational impacts of transmission outage events long beyond prior analyses, which looked six months ahead. A new joint PJM planning and operations project now models substations and facilities up to two years in the future to identify and mitigate conflicts caused by major transmission construction required by growing demand and generator retirements, particularly in the AEP, BGE, PEPCO, FE South and Dominion transmission zones.

-- Inverter-Based Resource Alert: In May, PJM issued an alert to communicate critical readiness actions to be taken by inverter-based resources. Steps included required unit adherence to NERC reliability standards for voltage stability and ride-through settings. In addition, PJM Manuals outline steps required for a Wind and Solar Unit Dispatchability Checklist and the need to accurately report and update reactive capability and provide active voltage regulation.

-- Wildfire Procedure: PJM stakeholders endorsed a Manual 13 revision to create the first PJM Wildfire Procedure. This codifies coordination and preventative measures PJM undertakes with Transmission Owners prior to and during wildfire events.

U.S. Department of Energy 202(c) Orders

PJM supported U.S. Department of Energy orders in 2025 to defer retirements of select dispatchable generation units in light of growing resource adequacy concerns. 

Beginning last spring, DOE directed the continued operation of Constellation’s Eddystone Generating Station units 3 and 4, both 380 MW steam plants in Pennsylvania, past their previously planned retirement dates.

In July, a DOE order approved a PJM request and directed Talen-owned Wagner Unit 4 in Maryland to run beyond emissions limits during reliability emergencies to help maintain voltage stability and prevent thermal overloads.

PJM collaborated with stakeholders to arrive at unit compensation guidelines to support continued operations of these facilities, rules that were approved by FERC late in 2025. 

Throughout the year, PJM continued efforts to assist stakeholders, states and unit developers in overcoming hurdles beyond its control to bringing dispatchable generation online.

Storage as a Transmission Asset

PJM picked up stakeholder work on how to integrate storage facilities as transmission assets into PJM operations. This work continues in the stakeholder process and is expected to enhance needed flexibility for PJM dispatch.

GridEx VIII

PJM practiced systemwide crisis response at the semiannual GridEx drill event Nov. 18–20. The exercise drew industrywide participation and, for the time, direct participation or observation by representatives from six states.

Click Here for a copy of the article.

Visit the PJM Interconnection website for more information.

Resource Links:

-- PJM Electricity Auction Prices Again At Cap Imposed By Gov. Shapiro’s Lawsuit Settlement, Without It Prices Would Be 59% Higher Driven By A.I. Data Center Demand; Grid Reliability Now Questioned [PaEN] 

-- PA Energy, Environmental, Citizen Advocates Call On PUC To Protect Ratepayers, Communities From Costs, Impacts Of A.I. Data Centers [PaEN]

Resource Links - Energy Affordability:

-- PUC: Most PA Electric Utility Consumers To See 3.7% To 10.6% Increase In Electricity Prices During The Next 3 Months Starting Dec. 1  [PaEN] 

-- Morning Call - Elizabeth Deornellas: How A.I. Data Centers Are Driving Up The Cost Of Electricity And What Grid Operators Can Do [PDF of Article]

-- Scranton Times - Chris Kelly Opinion: PPL Proposed 7% Rate Hike A.I. Data Center Driven  [PDF of Article] 

-- PJM Electricity Auction Prices Again At Cap Imposed By Gov. Shapiro’s Lawsuit Settlement, Without It Prices Would Be 59% Higher Driven By A.I. Data Center Demand; Grid Reliability Now Questioned  [PaEN] 

-- PA Capital-Star: Energy Market Watchers See Electric Bills In PA, Other States Rising As A.I. Data Center Demand Continues 

-- PaGasSwitch.com: Natural Gas Costs Increased From 9.26% to 57.5% Over The Last Year For Natural Gas Utility Customers Not Shopping For A Fuel Supplier  [PaEN] 

-- Post-Gazette - Anya Litvak: PUC Approves Columbia Gas Rate Increase - 13th Since 2008

-- PUC Highlights Ways Natural Gas Customers Can Manage Winter Energy Use, Costs, Explore Energy Affordability Options  [PaEN] 

-- PUC Publishes Updates To Low-Income Natural Gas, Electric Utility Usage Reduction Program Regulations  [PaEN]

-- PUC Chairman Highlights 'Extraordinary Challenges' Pennsylvania Families Are Facing This Winter With Energy Bills And His Appreciation For Groups Providing Assistance  [PaEN]

-- Post-Gazette - Anya Litvak: What’s Important In Affordable Energy?  A Conversation With A Carnegie Mellon Energy Justice Professor

-- Data Center Stampede Trampling PA Ratepayers Part I:  PA Utility Law Project - Utility Terminations Up 30% Already; Prioritize Existing Loads; Centers Need To Help Pay For Utility Assistance  [PaEN] 

-- Data Center Stampede Trampling PA Ratepayers Part II: PA Consumer Advocate - PUC Should Set Conditions For Centers To Be Served By The Grid; Set Power Curtailment Priorities [PaEN]

-- Data Center Stampede Trampling PA Ratepayers Part III:  PJM Market Monitor - Data Centers Have Cost Existing Ratepayers $16.6 Billion Already; Centers Should Bring Their Own Power Generation To Prevent More Large Price Spikes  [PaEN] 

-- PJM Electric Auction Impacts: 1 In 5 PA Households Report Problems Now Paying Energy Bills; Electric Utility Shutoffs Up 38.1% So Far This Year  [PaEN] 

-- PJM Electricity Auction: PJM Lost 2.8 Gigawatts Of Power Due To Reduced Reliability Rating Of Natural Gas Power Plants; Could Gain 12.2 Gigawatts By Increasing Reliability From Less Than 75% Now To An Achievable 90%  [PaEN] 

Resource Links - Who Pays:

-- PUC Invites Comments On Proposed Model Tariff To Balance A.I. Data Center Growth And Ratepayer Protection  [PaEN]

-- PUC Votes To Develop Rulemaking To Modernize Electric Interconnection Regulations; Proposed Rule Due In March  [PaEN] 

-- PUC Commissioners Agree On Need To ‘Get It Right’ On Reforming Grid Connection Process For Solar, Renewable, All Energy Sources To Protect Consumers, Grid Reliability  [PaEN]

-- Post-Gazette - Anya Litvak: PUC Proposes Special Treatment For A.I. Data Center Power Connections To Contain The Cost Burden On Existing Ratepayers [PDF of Article]

-- Federal Energy Regulatory Commission Orders PJM To Allow A.I. Data Centers To Connect Directly To Power Plants, Expedite Connections For Shovel-Ready Projects, Enhance Load Forecasting  [PaEN] 

-- WESA - Rachel McDevitt: PJM Grid Operator Covering PA Failing To Plan For Responsible A.I. Data Center Load Growth, Observers Say

-- PJM Market Monitor Files Complaint With FERC Saying PJM Is Proposing To Allow A.I. Data Centers To Connect To Grid That It Cannot Reliably Serve, Will Require Blackouts To Maintain Service  [PaEN]

-- NRDC: PJM Grid Members Fail To Recommend Any Of 12 Proposals To Prevent Existing Electric Ratepayers From Bearing The Costs, Reliability Risk Of Soaring A.I. Data Center Energy Demand  [PaEN] 

-- On The Eve Of New PJM Capacity Auction: Gov. Shapiro, 5 Other Governors Say PJM's Efforts To Deal With A.I. Data Center Demands Have Failed; Urge 'Decisive Action' To Avoid 'Extraordinarily’ High Prices  [PaEN] 

-- PA Capital-Star: Shapiro Urges FERC To Consider Consumer, State Regulator, Power Company Comments On A.I. Data Centers Connecting To PJM Grid Proposed By PJM’s Market Monitor To Protect Reliability, Affordability

-- The Center Square: Consensus For Soaring A.I. Data Center Power Demands Still Elusive Among PJM Members

-- PA Capital-Star: PJM Grid Operator Weighs Proposals To Manage A.I. Data Center Impact On Electricity Affordability And Reliability 

-- WITF/LancasterOnline: Mild Forecast For PA Winter Heating Bills In Peril As Natural Gas Prices Surge

-- PUC Directs Staff To Develop Rule On Winter Terminations, Payment Arrangements, Other Consumer Protections

Resource Links - Grid Reliability:

-- Utility Dive: FERC Members Raise Alarms About PJM Failure To Meet Reliability Target; Next Load Forecast Could Be Significantly Lower Due To Stricter Vetting Of Data Center Projects

-- North American Electric Reliability Corp: Electric Grid At Elevated Risk Of Insufficient Energy Supplies During Extreme Weather Due To Rising A.I. Data Center Demands, 'Precarious' Natural Gas Supplies  [PaEN] 

-- Utility Dive: North American Electric Reliability Corp: Winter Peak Demand Is Rising Faster Than Resource Additions

-- Reuters: US A.I. Data Center Demand Raising Power Risks This Winter, NERC Says

-- Bloomberg: US Faces Winter Blackout Risks From A.I. Data Centers’ Power Needs, NERC Says

-- WGEM: Illinois State Regulators Warn Of Impending Energy Shortfalls As PJM Capacity Prices Rise Again 

-- KSDK: A.I. Data Centers Are Sucking Illinois’ Power Grid Dry, Official Report Warns [PJM Service Area]

Related Articles This Week:

-- PA House Committee Approves Legislation Giving Local Officials Greater Say Over Regional-Scale Developments Like A.I. Data Centers, Warehouses  [PaEN] 

-- Sen. Boscola, Sen. Vogel Introduce Bipartisan Legislation To Promote Development Of Much-Needed Solar Energy Electric Generation Facilities And Lower Costs For Consumers  [PaEN] 

-- DEP: Seneca Resources Still Experiencing Spills, Releases While New Well Development Continues At Taft Shale Gas Well Pad In Middlebury Twp., Tioga County For 426 Days And Counting  [PaEN] 

-- Environmental Hearing Board Denies DEP Motion To Dismiss BCD Properties Appeal Over Its Illegal Disposal Of Oil And Gas Wastewater By Road Dumping; Case To Proceed On Its Merits  [PaEN]  

-- Spotlight PA: Map Shows Growing Number Of A.I. Data Centers Planned Across Pennsylvania 

NewsClips:

-- Altoona Mirror: PA House Moves Legislation Giving Local Governments Authority Over Projects Of Regional Significance [House Bill 1764] 

-- WHYY - Susan Phillips: New Financing Available For Philly-Area Homeowners Seeking To Install Rooftop Solar Energy Generation 

-- Warren Times: Don’t Count On Lower Electricity Prices In 2026 [Data Centers Driving Increases]

-- PennLive Letter: President’s War On Wind Energy Will Make Your Electric Bill Higher - By David Kyle, New Columbia

-- Wall Street Journal: Be Prepared To Keep Paying More For Electricity - A.I. Data Center Demands, Rising Natural Gas Prices, Grid Infrastructure Costs [PDF of Article]

-- Reuters Commentary: Five Energy Market Trends To Track In 2026 - The Year Of The Oil, LNG Natural Gas Glut 

-- PennLive Guest Essay: The Public’s A.I. Power Problem Is Not Electricity, It’s The Failure To Protect Ratepayers From Costs They Did Not Choose- Matt Hasan, Ph.D, CEO of aiRESULTS

-- TribLive: What To Look For In 2026 In Western PA [Data Centers, 4.5 GW Homer City Power Plant]

-- Scranton Times: A.I. Data Center Proposed In Ransom Twp., Lackawanna County [86th Data Center Building In The County]  [PDF of Article]

-- Scranton Times: Abandoned Mine Subsidence Sinkhole That Swallowed Car Filled, Patched In Blakely, Lackawanna County

-- Reuters Commentary: The 2025 Energy Transition In 8 Charts - Clean Wins, Dirty Setbacks 

[Posted: January 1, 2026]  PA Environment Digest

Delaware Currents Guest Essay: When Local News And Science Go Dark, The River Loses Its Voice

By Stroud Water Research Center

As Delaware Currents prepares to shut down, many of us who work in and care for the Delaware River Watershed feel the loss personally.

For years, editor Meg McGuire and her team offered something rare: journalism that listened to the river, explained its science, held institutions accountable, and connected people to the water that sustains them. 

DC’s departure is more than the end of a publication: It is a warning.

Because at the very same moment that DC’s doors are closing, the science that protects the Delaware River is facing an existential threat.

Across the country, federal funding for scientific research — especially environmental, water quality, and climate-related work — is being reduced or redirected at a scale that has stunned even seasoned policy analysts. 

Many of these cuts affect fields that rely on long-term, nonpartisan data collection. In the Delaware River Watershed, this means fewer stream monitors, fewer research technicians, fewer trained scientists, and more gaps in the record that tells us whether our rivers are getting cleaner or more polluted.

Science and Journalism: Twin Guardians of the Public Interest

Remember the Flint [Michigan] water crisis? It became a national reckoning because researchers refused to let data be dismissed, and local reporters refused to let residents’ concerns be ignored. 

Their work forced accountability, policy change and the protection of human health.

This is the power of science and journalism working together: 

They hold those in power to account and inform the public with facts rather than speculation.

Yet both fields face a crisis of trust and political polarization. 

NSF’s [National Science Foundation] Science and Engineering Indicators 2024 highlights a public that values research, but a Pew Research Center survey shows declining trust in scientists.

Journalism faces similar challenges. Research from Press Forward shows local newsrooms aren’t failing because people don’t care; they’re failing because people don’t fully understand the cost, labor and civic importance of the work.

Both science and journalism suffer from a kind of mystique: When done well, they appear effortless because most of the effort happens out of sight. 

But it is precisely this unseen work — this daily, careful, rigorous labor — that keeps our communities safe.

A River Protected by Both Science and Storytelling

Here in the Delaware River Watershed, we have witnessed how journalism and science can illuminate each other. 

When Chris Mele and Lauren Yates, reporting for DC, covered Stroud Water Research Center’s Cut the Salt campaign last winter, they helped thousands understand a growing crisis: road salt infiltrating our streams, threatening ecosystems, and corroding infrastructure.

Dozens of groups and hundreds of local residents waded into streams to collect chloride data last January during Winter Salt Week and again in October. 

They weren’t just participating in science; they were demonstrating something more profound: 

Even as national funding shrinks, local communities can still rise to meet an urgent challenge.

It is a hopeful story. And yet volunteer energy and grassroots collaboration cannot replace sustained, long-term scientific investment. 

Nor can they replace a professional newsroom whose full-time mission is to shine light on public issues.

The Gravity of This Moment

The Delaware River supplies drinking water to 15 million people. It supports economies, ecosystems, and communities across four states. 

But we can’t protect what we can’t measure, and we can’t act on dangers we can’t see.

Right now, we are at risk of losing both the measurements and the messengers.

If long-term scientific monitoring is halted or reduced, we might not detect contamination until it is too late. 

If local journalism fades, communities might not know when policies or decisions put their water at risk. 

And when misinformation fills the silence left by both, the public loses its ability to hold anyone accountable.

Where We Go From Here

The solution will not come solely from Washington or major philanthropies. It will come from the communities who depend on the Delaware River and the institutions that serve them.

Supporting local journalism and local science is not charity. It is an investment in our own protection — in the data, transparency, and accountability that keep our freshwater resources safe.

As DC closes, we should honor its work by refusing to let silence replace it.

 Support the newsrooms that keep the public informed. 

Support the research organizations that monitor our rivers. 

Join community science efforts like Cut the Salt. 

Ask local leaders what they are doing to safeguard long-term water quality data.

Because the river will remain. The question is whether we will still hear what it’s telling us.

Click Here for a copy of the guest essay.

Visit the Delaware Currents website for more information, for the last time.

Resource Link:

-- Blue Ridge Cable News13: The Delaware Currents Is Shutting Down

[Posted: January 1, 2026]  PA Environment Digest

PA Resources Council Suggests 5 Green New Year's Resolutions For 2026

By Mary Beth Mueller, PRC

If you’re ready to adopt a “greener” lifestyle in the New Year, the Pennsylvania Resources Council – recognized as a state and national leader in waste reduction and recycling – suggests adopting the following 5 habits for becoming more environmentally friendly in 2026.

1. Get Creative In The Kitchen & Reduce Food Waste

Learn how to eat well, save money and waste less while preventing and reducing food waste.  Simple strategies such as planning meals, freezing food before it spoils, eating leftovers, donating excess catered meals and making shopping lists can result in a significant reduction of the amount of food tossed each year.  Learn more here.

2. Roll Up Your Sleeves - Compost

Take part in a PRC “Backyard Composting” workshop or webinar to learn how to turn kitchen scraps and yard debris into a valuable resource for your garden.  Learn more here.

3. Protect Your Watershed - Install A Rain Barrel

Rain barrels are a great way to conserve water, supplying non-chlorinated water for gardening by collecting and storing rainwater from your roof through a connection to your downspout.  

Take part in a PRC “Watershed Awareness/Rain Barrel” workshop or webinar to learn about problems associated with stormwater runoff, discover watershed-friendly landscaping techniques and hear how to conserve water at home.  Learn more here.

4. Expand Your Recycling Effort - Recycle Glass In Particular

Glass is amazing.  It’s 100% recyclable and can be recycled endlessly, and recycling glass uses 70% less energy than creating glass from raw materials.  In a landfill glass takes one million years to degrade – yet a glass bottle can go from a recycling bin back to a store shelf in just 30 days.  Learn more here.

5. Don't Just Walk By - Focus Your 'Lens On Litter'

Photos help to heighten litter consciousness by showing how it threatens public health and safety, scenic beauty, property values, the environment, pets and wildlife. Since exposure leads to prevention, take pictures of blight and then organize a small clean up effort at the site.

PRC’s annual “Lens on Litter” photo contest launches in January (all entries due by October 31).  Amateur photographers can win prizes of $500 in adult and student categories. Learn more here.

Pennsylvania Resources Council envisions a Pennsylvania where nothing is wasted.  

Click Here for PRC’s resolutions.

Visit PRC’s Resources webpage for a wealth of recycling information including best practices, municipal resources and online brochures.

For more information on programs, initiatives and special events, visit the PA Resources Council website.  Click Here to sign up for regular updates, follow PRC on Twitter or Like them on Facebook.  Click Here for PRC’s Events Calendar.  Click Here to support their work.

[Posted: January 1, 2026]  PA Environment Digest