PJM’s $8.7 Billion Interconnection Cost Drop Shows Transmission Planning Is Becoming a Generation Cost Story

PJM’s June 16 planning update clears the bar for publication because it gives a hard number to something power-market participants often discuss too vaguely: transmission planning can materially change the cost of getting new generation online. In the second study phase of PJM’s last transition cycle to the new interconnection process, the grid operator says network-upgrade costs dropped by $8.7 billion across the projects studied.

The headline facts are concrete. PJM says Phase II covered 270 projects representing about 30 gigawatts of new generation at full output. It also notes that 180 projects withdrew after Phase I, which explains part of the cost change. But PJM says the bulk of the reduction came from broader transmission work approved by the PJM Board in February across eastern, southern, and western parts of the footprint.

Transmission planning is becoming part of the generation cost stack, not just a background engineering exercise.

That is the important Grid Report angle. This is not just a queue-cleanup story. It is a transmission-economics story. When backbone upgrades are planned through the regular regional expansion process instead of being loaded onto individual interconnection studies one project at a time, the cost to connect new supply can fall sharply. That matters for developers, for states trying to add capacity, and for consumers who ultimately care whether new generation can come online without endless delay and cost inflation.

It also matters because PJM is trying to solve two timing problems at once. The region needs more supply as older generation retires and demand rises, and it is also under pressure to integrate large new loads including data centers. AI demand does not connect directly to this study, but the operator implication is clear: load growth looks much harder to manage when the supply side stays trapped behind expensive and fragmented upgrade bills.

PJM’s own framing is unusually direct. The operator says proactive planning should help more generation get built, make better use of planned transmission rights of way, and support lower prices as supply catches up with growing demand. That does not mean every cost problem disappears. It does mean transmission planning is becoming one of the most important levers in whether the region can add capacity on an economically credible timeline.

There is also a policy angle beyond PJM itself. The announcement lands ahead of PJM’s implementation work for FERC Order 1920, which is meant to push long-term regional transmission planning and cost allocation forward. In practice, this June 16 study update is a live example of the core argument for doing more planning earlier: if the system waits for each project to shoulder every network need alone, connection costs can stay bloated and supply can arrive too slowly.

The publishable conclusion is straightforward: in the current market, transmission planning is no longer a back-office engineering topic. It is becoming part of the generation cost stack, the affordability conversation, and the timetable for how fast regions can serve both ordinary load growth and AI-linked power demand.

PJM Inside Lines, “Proactive Planning Lowers Connection Costs by $8.7 Billion, Paves Way for More Generation,” published June 16, 2026: https://insidelines.pjm.com/proactive-planning-lowers-connection-costs-by-8-7-billion-paves-way-for-more-generation/

PJM Inside Lines, “PJM Board Approves Transmission Improvements Needed for Grid Reliability,” February 2026: https://insidelines.pjm.com/pjm-board-approves-transmission-improvements-needed-for-grid-reliability/

PJM Inside Lines, “PJM Outlines Long-Term Transmission Plan in FERC Filing,” 2026: https://insidelines.pjm.com/pjm-outlines-long-term-transmission-plan-in-ferc-filing/