U.S. battery storage projects wait 3-7 years in interconnection queues because grid rules treat storage like generation instead of a grid asset

Over 2,600 GW of generation and storage capacity is stuck in U.S. interconnection queues as of 2025, and battery storage projects face median wait times of 4+ years from interconnection request to commercial operation -- double the timeline from a decade ago. The core problem is that Independent System Operators (ISOs) and Regional Transmission Organizations (RTOs) classify battery storage as 'generation' in their interconnection study processes, subjecting it to the same serial queue studies designed for power plants, even though storage can actually reduce grid congestion rather than cause it. Why it matters: Because storage is treated as generation in interconnection studies, each new battery project triggers expensive and time-consuming system impact studies that assume the battery will inject power at maximum output simultaneously with every other queued project, producing unrealistic upgrade cost allocations. So developers receive interconnection cost estimates in the tens of millions of dollars for projects that would actually reduce local congestion if operated correctly. So developers withdraw -- withdrawal rates have increased sharply -- and the projects that could help integrate renewables and defer transmission upgrades never get built. So the 11 GW of battery storage that reached commercial operation in 2024 (a record) represents a fraction of the pipeline, and Wood Mackenzie projects an 11% contraction in utility-scale storage in 2026 due to these barriers. So regions with the highest renewable penetration and the greatest need for storage (CAISO, ERCOT, SPP) face the longest queues, creating a paradox where storage is most needed exactly where it is hardest to connect. The structural root cause is that interconnection processes were designed in the 1990s-2000s for one-directional power flow from large thermal generators. The study methodology assumes worst-case simultaneous injection from all queued resources, which produces absurd results when applied to batteries that charge and discharge at different times. FERC Order 2023 attempted reforms but left implementation to individual ISOs, resulting in fragmented rules, and no ISO has fully implemented storage-specific interconnection pathways that model the bidirectional, time-shifting nature of batteries.