The U.S. interconnection queue for grid-scale generation and storage has reached 2,200 gigawatts, according to S&P Global Commodity Insights, leaving battery storage and hybrid solar-plus-storage developers facing multi-year delays even as federal regulators push structural reforms through compliance cycles across regional grid operators.
Background
The Federal Energy Regulatory Commission issued Order No. 2023 in July 2023, its most sweeping overhaul of generator interconnection rules in decades. The order adopted reforms to reduce backlogs for projects seeking grid connection, improve certainty in interconnection processes managed by dozens of transmission providers nationwide, and ensure transmission access for new technologies. The rule replaced the legacy first-come, first-served serial review process with a mandatory cluster study approach. Under this first-ready, first-served model, transmission providers conduct larger interconnection studies encompassing numerous proposed generating facilities rather than separate studies for each-an approach designed to increase efficiency and minimize delays.
The scale of the problem is significant. At the end of 2022, more than 2,000 gigawatts of generation and storage sat in interconnection queues nationwide-as much capacity as all operating U.S. power plants combined-with projects facing average wait times of up to five years. The timeline from interconnection application to commercial operation in PJM has risen from less than two years in 2008 to over eight years in 2025.
Details
Order 2023 compliance filings have progressed unevenly across regional transmission organizations. American Electric Power filed a petition with FERC requesting an extended compliance deadline and calling on regulators to address oversights the implementation process has revealed, though FERC has so far only responded to the deadline extension request. The interconnection backlog has grown to 2,200 GW, with 111 GW of hybrid solar-plus-storage projects added in the past year alone, according to S&P Global Commodity Insights.
Order 2023 also imposes firm study deadlines and financial penalties on transmission providers that miss them. AEP's FERC and RTO strategy vice president Stacey Burbure flagged that "the elimination of the Reasonable Effort Standard and the imposition of penalties is very fraught," raising concerns that the new penalty system could generate litigation and further delay interconnection processes.
Meanwhile, individual grid operators are implementing their own accelerated tracks. On November 20, 2025, PJM finalized new interconnection agreements and completed the first transition cycle of its reformed process; the participating projects are the second cohort to receive interconnection agreements, following the Fast Lane projects. Twenty-one battery energy storage projects received interconnection agreements in that cycle; if all become operational, they will add 1.9 gigawatts of storage capacity to PJM's network. PJM expects to finalize interconnection agreements for the remaining Transition Cycle 2 projects in the first quarter of 2027.
MISO and SPP have both received FERC authorization for Expedited Resource Addition Study (ERAS) processes. On December 1, 2025, MISO announced its second ERAS cycle, comprising 6.1 gigawatts of proposed new capacity, with battery storage as the primary project type. SPP's ERAS process is evaluating approximately 13 gigawatts of capacity, with hybrid solar-plus-storage projects as the leading project type after thermal generation.
For hybrid projects, SPP offers an additional shortcut: the Surplus Interconnection Process allows a new generator such as a battery to connect using existing unused interconnection capacity under a Surplus Interconnection Agreement, with no new transmission upgrades required and typical timelines of 6 to 12 months instead of several years.
The persistent backlog is reshaping capital allocation. Renewable platform M&A activity rebounded in 2025 with a specific focus on acquiring interconnection queue positions, which have emerged as a primary currency in the sector as wait times stretch to four to five years in PJM, MISO, and CAISO. Some independent power producers are acquiring legacy solar assets specifically to retrofit them with battery storage, using existing points of interconnection to bypass frozen queues.
On December 18, 2025, FERC directed PJM to overhaul its rules on co-located generation serving large loads-a proceeding with direct implications for hybrid storage configurations. The Commission found PJM's current tariff unjust and unreasonable, directing PJM to implement revisions clarifying steps entities must take to effectuate co-located load arrangements, establish three new transmission services, and create new behind-the-meter generation rules.
Outlook
Interconnection outcomes increasingly depend on regional ISO market structure and utility planning practices-not just queue position-creating materially different grid access risk profiles across U.S. regions, according to energy analytics firm Enverus' 2026 interconnection outlook. Processing the backlog and fully adopting new interconnection procedures will take several more years. While PJM has promised one-to-two-year wait times under its reformed system, the sector awaits evidence that these targets are achievable. For storage developers, the near-term strategic priority remains securing a validated queue position or an existing point of interconnection before entering project finance and procurement cycles.
