FERC has ordered all six federally regulated regional grid operators to defend or reform their rules for connecting large electricity users. The outcome will shape who pays for grid upgrades, which projects receive protection, and how quickly AI infrastructure and advanced manufacturing can connect.
Signal Snapshot
What changed: On June 18, 2026, FERC issued tailored section 206 show cause orders to all six RTOs/ISOs under its jurisdiction – PJM, MISO, SPP, CAISO, ISO-NE, and NYISO – directing each to justify or reform the tariffs that govern how data centers, manufacturing facilities, and other large energy users connect to the electric grid. Each operator and its transmission owners have 60 days to respond across five reform categories.
Why now: The Commission frames the action as a response to load growth from hyperscale AI data centers, domestic manufacturing expansion, and electrification. DOE explicitly says the nation is transitioning from decades of stagnant demand to unprecedented, exponential load growth. Existing interconnection and transmission service frameworks were designed for an era of stagnant or slowly growing demand. The mismatch between legacy tariff structures and the speed, scale, and operational profile of new large loads has become a binding constraint on investment, national security, and the innovation economy.
Who is exposed: Every large-load developer – data center operators, advanced manufacturing facilities, electrification aggregators – with projects in the six RTO/ISO footprints now faces a compressed regulatory negotiation window that will determine the cost and schedule of grid access. Transmission owners within those footprints must justify their existing tariff structures or revise them. Investors with committed or pipeline large-load projects face tariff uncertainty during the 60-day response window and the FERC review that follows.
What to watch: Whether RTOs/ISOs defend or reform; generation-adequacy reports; FERC’s response to RTO/ISO filings; the September 7 DOE Needs Study comment deadline; and NERC’s December 31 reliability standards deadline.
The Five-Category Framework
The June 18 orders structure the tariff review around five categories, each targeting a governance gap in the legacy interconnection framework.
Study processes and alternative technologies
The first category demands efficient application and study processes, including consideration of alternative transmission technologies. The Commission’s instruction signals that business-as-usual queue management is not acceptable.
Cost shifting and transparency
The second category requires operators to prevent cost shifting and provide transparency into transmission costs. This is the central distributional question: who pays for the network upgrades new large loads require? In the author’s reading, “preventing cost shifting” implies an obligation to allocate costs to the entities that cause them rather than socializing them across all ratepayers. The orders stop short of specifying a particular cost-allocation methodology, leaving each RTO/ISO to propose its own approach within a cost-causer principle whose precise boundaries remain undefined.
Co-location and behind-the-meter generation
The third category addresses loads physically co-located with generation or served by behind-the-meter resources. When a data center connects adjacent to a power plant or uses on-site generation, what transmission services does it require, what charges should it pay, and what reliability obligations does it carry? In the author’s assessment, co-location is among the most contested areas of large-load interconnection policy. The December 2025 PJM co-location order and SPP’s High Impact Large Load initiative established initial precedents; the June 18 orders extend the question to all six operators.
Flexible large loads
The fourth category directs operators to provide transmission services for loads that can modulate consumption in response to grid conditions. Loads capable of demand response during system stress should face tariff structures reflecting their operational flexibility.
Electrically proximate generation studies
The fifth category requires a process for studying generating facilities that serve electrically proximate and co-located loads.
The Three-Regulator Convergence
The June 18 orders do not exist in isolation. Within four weeks, two additional instruments converged on the same problem.
On July 9, 2026, the Department of Energy released the draft National Transmission Needs Study, identifying a “pressing need for additional transmission infrastructure due to load growth” and finding that the majority of transmission congestion concentrates in just 5 percent of operating hours. Based on more than 120 published reports, it provides the demand-side evidence base for transmission investment. Its findings give geographic specificity: NYISO, NorthernGrid South, and MISO show the highest within-region congestion costs; interregional links between ISO-NE and NYISO and between NorthernGrid and WestConnect offer some of the highest congestion-relief value.
On July 16, 2026, the Commission directed NERC to develop Reliability Standards addressing computational-load integration risks and to create registry criteria for computational load entities – a new regulatory category that did not previously exist. Both are due December 31, 2026.
In the author’s assessment, tariff reform, transmission needs identification, and computational-load reliability standards address three dimensions that must be solved simultaneously for the investment case to hold: who pays, what is needed, and how it operates safely.
Investment Certainty and the 60-Day Window
For investors, the core question is what follows the 60-day window. Each RTO/ISO must either justify its existing tariffs as “just and reasonable” without large-load provisions, or file reforms. Both paths create uncertainty.
If an operator defends its existing tariffs, the Commission must decide whether the defense is adequate – a decision without a statutory deadline that could produce further proceedings, including potential section 206 hearings. If an operator files reforms, those reforms must be reviewed, contested by stakeholders, and approved before taking effect. In either case, developers awaiting interconnection cannot price the transmission component of their investment with confidence until the tariff framework settles.
In the author’s reading, Chairman Swett’s statement that FERC intends to “provide certainty for investors by directing the markets to protect existing deals” provides a directional signal, not an operational guarantee. The Commission has not specified what “protecting existing deals” covers – queue positions, executed interconnection agreements, or another category. The answer will determine which projects are insulated from tariff changes. The 30-day generation-adequacy reports may offer early visibility into whether RTOs/ISOs believe existing generation is adequate for committed and anticipated loads, but those reports are informational, not binding.
The DOE Needs Study adds a longer-horizon signal. In the author’s assessment, the finding that MISO approved the largest transmission portfolio in U.S. history in 2024, and that MISO, SPP, PJM, and ERCOT have all recently approved record-scale transmission plans, suggests that regional transmission investment is already accelerating. Whether the June 18 orders accelerate or redirect that investment, in the author’s view, depends on RTO/ISO responses and the Commission’s subsequent rulings – a question that turns on an outlook, not on a source-confirmed projection.
What to Watch
FERC also required generation-adequacy reports within 30 days of the orders. Their filings and conclusions should be reviewed alongside the tariff responses because they may reveal where committed demand is already outrunning available generation.
FERC’s 60-day tariff-response requirement: RTO/ISO tariff justification or reform filings are due under FERC’s 60-day requirement following the June 18, 2026 order. RTO/ISO responses will define the scope of the next phase.
September 7, 2026: Public comment period closes for the DOE National Transmission Needs Study. The final Study will inform federal transmission policy, including DOE’s authority to designate National Interest Electric Transmission Corridors.
Q3-Q4 2026: FERC review of RTO/ISO responses. The Commission may accept filed reforms, set them for hearing, reject them, or initiate further proceedings.
December 31, 2026: NERC deadline for computational-load reliability standards and registry criteria.
Cross-cutting watch item: Whether tariff reform, transmission needs assessment, and reliability standard development are coordinated or run in independent silos. Investment certainty depends on progress across all three dimensions.
Sources
- FERC: Large Load Integration Action (June 18, 2026)
- FERC: July 2026 Commission Meeting Summary
- Department of Energy: National Transmission Needs Study
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