Without the cap, the price would have been at least 58.8% higher at $529 MW/day driving electricity bills even higher.
Electricity demand has surged driven primarily by A.I. data centers, while generators have failed to bring new energy resources online fast enough.
As a result, capacity prices have skyrocketed.
PJM’s 2025–26 auction, held in July 2024, resulted in costs of $14.7 billion, an increase of more than 800 percent from the prior year.
The subsequent auction, held in July 2025, drove costs even higher — reaching $16.1 billion.
This December auction had a clearing price total of $16.4 billion.
"This auction leaves no doubt that data centers’ demand for electricity continues to far outstrip new supply, and the solution will require concerted action involving PJM, its stakeholders, state and federal partners, and the data center industry itself,” said Stu Bresler, Executive Vice President – Market Services and Strategy, who becomes chief operating officer on Jan. 7.
Gov. Shapiro said in a statement-- “I sued PJM because it is unacceptable for them to do nothing as consumers pay sky-high utility bills while getting nothing in return.
“My Administration has once again stopped billions of dollars in unnecessary and unjustified energy price hikes from being passed on to families and businesses.
“ PJM needs real reform and they are running out of time to protect consumers from their inaction.
“My Administration will continue to build more energy generation right here in the Commonwealth and push PJM to fix its broken process so we can lower costs, strengthen reliability, and keep more money in the pockets of Pennsylvanians.”
This is the last auction subject to the market cap settlement agreement.
On December 3, Gov. Shapiro and five other governors in the PJM service territory wrote to the PJM Board urging them to immediately extend the market price cap agreement for one further auction to be held in June 2026 to allow time for additional reforms to be adopted. Read more here.
Results Do Not Meet Reliability Standard
PJM said the capacity of the resources procured in the auction, plus Fixed Resource Required resources, is short of PJM’s reliability requirement by 6,623 MW, meaning that the committed supply is less than what would be required to meet the one-event-in-10-year reliability standard of a 20% reserve margin.
This does not necessarily mean, however, that the PJM system will be unable to serve load reliability in the delivery year.
PJM continues to hold a reserve margin of 14.8%, and there are several mitigating factors that could improve the reliability picture for the system in the 2027/2028 Delivery Year.
5,100 MW Of 5,250 MW Of New Demand Is Data Centers
PJM said the forecast peak load for the 2027/2028 Delivery Year is approximately 5,250 MW higher than the forecast used for the 2026/2027 capacity auction.
Nearly 5,100 MW of that increase is attributable to data center demand.
Energy Mix
The cleared resource mix in this auction includes: 43% natural gas, 21% nuclear, 20% coal, 5% demand response, 4% hydro, 2% wind, 2% oil and 1% solar, according to PJM.
The auction cleared 774 MW of new generation and generation uprates.
The total amount of supply in the PJM service area increased from 196,650 MW to 200,994 MW, or an increase in the total amount of supply by 4,344 MW installed capacity
Click Here for the PJM announcement.
Reactions
Tom Rutigliano, Natural Resources Defense Council, said "Summer 2027 will be the first time in PJM’s history it expects to not have enough power to reliably meet demand because of new data center forecasts and the ongoing risk of fossil fuel generators failing during winter storms.
"Data centers are applying to connect to the grid much faster than the grid can keep up. Right now, PJM and its member utilities are promising power they simply don’t have.
“Most troubling is that there was only 956 MW of new supply, even though this was the third year of very high prices. That’s less than a 1% increase in supply.
"Delays in building transmission, supply chain issues, barriers to siting new renewables, and PJM’s interconnection queue have combined to leave the region locked up and simply unable to build power plants. We’re throwing money in a hole right now.
“PJM must take action to protect the public from cost and reliability impacts by requiring new data centers that want to connect to the grid bring their own capacity.
"Otherwise, electricity bills will continue to rise and reliability will suffer. Worse, nearly all of the billions of dollars that customers will be charged will go to existing power plants, not to new supply and transmission infrastructure PJM desperately needs.”
The Reliable Grid Project issued this statement--
“Developers are literally waiting in line to build the energy projects states need, but PJM is really struggling to get this new supply connected to the grid quickly enough,” said Jon Gordon, Director, Advanced Energy United. “Reforms are in the works, but don’t go far enough, and in the meantime, some energy projects have been languishing in the PJM queue for four or five years.”
Nikhil Kumar, Program Director at GridLab, warned that these factors are creating a "perfect storm" of increased demand and limited supply, leading to higher costs for consumers and potential reliability risks.
“Data centers are being built at a pace that far outstrips the ability of the system to balance supply and demand,” said Clara Summers, Consumers for a Better Grid Campaign Manager, Citizens Utility Board of Illinois (CUB). “This auction result underscores the urgent need for reforms to ensure affordability and reliability across PJM.”
“While the price cap has provided short-term relief, it’s clear that PJM’s interconnection process is broken,” said Kumar. “Texas has demonstrated that adding energy resources like solar, wind, and batteries can significantly reduce grid risks and costs. PJM must act quickly to implement reforms and bring energy projects online to address the growing demand.”
The Clean Power PA Coalition said-- “The latest PJM capacity auction signals still more electric bill increases ahead for millions of Pennsylvanians.
“Even with Governor Shapiro’s effective intervention to cap PJM auction prices, electric bills will increase yet again with this auction.
“This will come after most Pennsylvanians were hit with annual electric bill increases of more than $100 this past year, with price hikes ranging from 12% to 27%.
“What’s worse, those higher prices don’t necessarily mean there will be enough capacity to meet demand during periods of extreme weather during 2027-28, which could increase the risk of blackouts.
“The backlogged PJM process to approve new energy sources to the grid, especially many backlogged cheap, clean energy projects awaiting approval, means that PJM is not keeping up with the rapidly growing demand for electricity, driven largely by huge data centers.
“This failure to bring new energy online quickly enough, combined with PJM’s outmoded design for purchasing energy and its failure to build out more electric transmission, is driving up prices for all of us.
“The auction price cap that Governor Shapiro successfully negotiated with PJM a year ago was intended to give PJM time to institute long-term solutions.
“Over that period, PJM has accomplished little to address the underlying problems that are driving up prices. Unless extended, the next auction will take place this summer without adequate cost protections for electric bill customers.
“PJM must act with urgency to put an end to these outrageous electric bill hikes. For starters, it must remove barriers to cheap, clean, and reliable clean energy by quickly clearing its huge backlog of new energy projects waiting to connect to the grid.
“It must continue reforming its process for purchasing energy to ensure that people are not overpaying for their electricity.
“Finally, it must improve its transmission planning to more quickly build out more long-range transmission lines.”
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]
-- 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 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]
-- 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]
-- 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]
-- 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:
-- 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
Related Articles This Week:
-- Pennsylvania BRIGHT Expands Statewide To Remove Barriers To Bringing Affordable Solar Energy To PA Homeowners Left Out Of Transition To Clean Energy Options [PaEN]
NewsClips:
-- Bloomberg: Latest PJM Power Auction Set To Deepen Affordability Concerns
-- KSDK: A.I. Data Centers Are Sucking Illinois’ Power Grid Dry, Official Report Warns [PJM Service Area]
-- PJM Outlines Long-Term Electric Transmission Plan In FERC Filing
-- Morning Call/Inquirer: Poll: How Pennsylvanians Feel About A.I. Data Centers: 70% Concerned About Water Use; 71% Concerned About Electricity Use
-- Altoona Mirror: Groups Urge Shapiro To Dial Back Support For A.I. Data Centers [PDF of Article]
-- Bloomberg: New York Utility Says Queue For A.I. Data Center Power Users Has Tripled
-- Post-Gazette: President’s Order To Block State Regulation Of A.I. An ‘Abuse Of Power,’ State Democratic Sen. Costa Says
-- PA Capital-Star: PA’s Republican Attorney General, Lawmakers Contend With President’s Order Blocking A.I. Regulations
[Posted: December 17, 2025] PA Environment Digest
