26MAY

75 GW added, PJM still hit an emergency

3 min read

11:34UTC

FERC logged 75 GW of new US summer generating capacity since 2025, with Texas operator ERCOT alone adding 26 GW, yet PJM still triggered emergency curtailment weeks before summer peak as data-centre load growth outpaced supply.

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Key takeaway

Seventy-five gigawatts of new capacity has not closed the gap opened by data-centre demand growth.

The Federal Energy Regulatory Commission (FERC) reported 75 GW of new US summer generating capacity added since 2025, with Texas grid operator ERCOT accounting for roughly 26 GW of it.⁠¹ Capacity rose at the fastest pace in years, and PJM still triggered its emergency curtailment in mid-May, weeks before the summer peak.

The supply addition lands against a demand overhang it cannot close. ERCOT's own large-load queue stood at 225 GW, and PJM's demand is now growing about 5 per cent a year after a grid that barely moved from 2005 to 2020. New load has raised the baseline so far that a routine May heat event trips emergency tools that used to belong to August. The headline 75 GW is real; the gap behind it is wider still.

The tally also covers the period in which FERC set end-June as the deadline to settle the RM26-4-000 permanent co-location rule. That the emergency arrived before the rule, and despite the largest supply response on record, is the clearest reading available that capacity additions are not keeping pace with data-centre demand.

Deep Analysis

In plain English

FERC (the Federal Energy Regulatory Commission) is the US federal agency that oversees electricity transmission and wholesale power markets. It reported that 75 gigawatts of new generating capacity came online across the US since 2025, roughly equivalent to 75 large power stations. Texas, managed by ERCOT (the Electric Reliability Council of Texas), added about 26 GW of that, mostly solar and wind. Despite this, PJM, the grid operator covering the US north-east, still triggered emergency procedures in May because data-centre load is growing so fast that 75 GW of new supply has not kept pace with demand. It is like adding 75 lanes to a motorway while traffic doubles: the motorway is still jammed.

Deep Analysis

Root Causes

The 75 GW addition is geographically concentrated in Texas, the Southwest, and the Midwest, driven by low-cost solar and wind land; PJM's grid covers the mid-Atlantic and Midwest where the new data-centre load is densest but where permitting, transmission constraints, and land costs slow new supply.

ERCOT's exemption from FERC jurisdiction means its 26 GW of addition cannot be dispatched to serve PJM load during emergencies, making the national headline figure structurally irrelevant to PJM's specific gap.

What could happen next?

Risk
PJM's structural capacity deficit, not resolvable by supply additions in other grid regions, means summer 2026 peak demand events carry a genuine rolling-blackout risk in the mid-Atlantic states.
Consequence
A PJM rolling blackout during summer 2026 peak that affects data centres and residential customers simultaneously would accelerate federal action on demand-side curtailment, effectively confirming the BTM-as-reserve posture before RM26-4-000 is settled.

Source Landscape

This story draws on neutral-leaning sources

Primary parallel: The 2003 Northeast blackout affected 55 million people across eight US states and Canada; it was caused by a software bug at FirstEnergy Ohio that cascaded through a transmission network not designed for the new load patterns of the early internet era; it triggered NERC mandatory reliability standards in 2007. The AI load surge is a slower-moving structural shift, but the mismatch between load growth and system design is structurally analogous.

Counter-parallel: California's 2020 rolling blackouts during a heat dome were attributed at the time to inadequate reserve margins, but subsequent CPUC investigation found the primary cause was an ERCOT import failure and misaligned resource adequacy accounting; the lesson was that geographic supply-demand mismatch, not pure capacity shortage, drove the failure, a risk PJM faces as its ERCOT-domiciled new supply cannot easily serve mid-Atlantic load centres.

Consensus view: Brattle Group economists Jurgen Weiss and J.

Michael Hagerty, in a 2025 grid adequacy report commissioned by PJM, found that the structural load-growth from AI data centres in the 14-state region is tracking at 4.8-5.3 per cent annually through 2030 versus 0.2-0.4 per cent historically, and that even a 75 GW national supply addition concentrated in solar and wind does not address PJM's specific capacity deficit because geography and intermittency mean most of the new ERCOT solar is not available to PJM's mid-Atlantic grid.

Counter-view: FERC commissioner Mark Christie dissented from the Commission's May capacity assessment, arguing the 75 GW figure is misleading because it conflates nameplate capacity with available capacity: intermittent resources count at 10-15 per cent of nameplate in PJM's capacity market, meaning the effective dispatchable addition is closer to 15-20 GW rather than 75 GW, and that the emergency was predictable given the maintenance scheduling that coincided with the heat event.

Key tension: Whether PJM's gap reflects a structural data-centre demand overhang or the compound of intermittent supply counting and poor maintenance scheduling determines whether FERC needs permanent demand-side controls or better maintenance coordination.

Sources:Utility Dive

Mentions:California →Canada →Texas →FERC →PJM Interconnection →FERC Docket RM26-4-000 →ERCOT →

First Reported In

Update #4 · Grid wins power to switch off data centres

Utility Dive· 26 May 2026

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