Storage is no longer a side category in US interconnection queues — it's the largest one. Of the roughly 2,061 GW sitting in US interconnection queues at the end of 2025, 749 GW was storage, more than any other single resource type, according to Lawrence Berkeley National Laboratory's "Queued Up" tracking. Yet almost all the public attention on grid connection delays goes to data centers and generation, not to the battery projects competing for the exact same queue slots.

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WHERE THE QUEUE ACTUALLY SITS, BY MARKET

BESS in US Interconnection Queues — 2026 MISO: ~50 GW of BESS capacity within a 650 GW total queue
NYISO: backlog doubled from 176 to 350 projects (2018–2025); only ~9% of BESS submissions reach commercial service
ERCOT: fastest process of any US market, but BESS applications fell roughly 50% in H2 2025 vs H1, driven largely by policy uncertainty
Median wait time across US queues: 4–5 years, per LBNL's Queued Up 2026 edition

WHY THE BATTERIES ARE RARELY THE PROBLEM

A BESS project's interconnection delay is almost never about battery cell availability — global utility-scale BESS deployment grew roughly 36% year-over-year through the first three quarters of 2025, and cell supply has scaled to match that growth. The constraint sits elsewhere: interconnection studies, grid-code compliance, and — as with every other category we track — the step-up transformers and switchgear that connect the storage system to the grid, which face the same multi-year lead times as every other power equipment buyer right now.

REFORM IS UNEVEN ACROSS MARKETS

Different grid operators are handling the storage queue very differently. CAISO has moved to a "first-ready, first-scored" system that prioritizes projects aligned with state resource planning. NYISO's reformed process aims to get projects from application to construction roughly 50% faster than before. ERCOT remains the fastest process of any major US market on paper — but BESS-specific application volume there fell sharply in late 2025, tied to policy uncertainty rather than grid capacity.

For a developer comparing markets, "fastest interconnection process" and "fastest realistic path to energization" are not the same question — and the gap between them is almost always equipment lead time, not paperwork.

WHAT THIS MEANS FOR PROJECT SEQUENCING

Because BESS queue timelines now run 4–5 years in the median case, and step-up transformer lead times can run 20–48 months on their own, equipment procurement for a storage project increasingly needs to start well before the interconnection study is even complete — not after, once a queue position is secured. Waiting for grid certainty before ordering equipment is, in practice, the sequencing mistake that turns an already long queue into an even longer one.