Battery Storage — Fleet & Pipeline Analysis

Key Finding: The US battery storage fleet, while broadly distributed, exhibits significant concentration in key states like Texas and California and in several large-scale projects, with a median plant vintage of 2023 indicating recent rapid expansion.

Geographic Distribution and Concentration

Deployment of battery storage is widespread across 48 states, yet certain regions lead substantially in both plant count and total capacity, indicating varied adoption rates and market drivers across the US.

• Texas (TX): 406 plants, representing 62.8 GW of capacity, leads the nation in both plant count and total capacity.
• California (CA): With 348 plants and 45.7 GW, California is the second-largest market by both metrics.
• Massachusetts (MA): 146 plants for 1.8 GW demonstrate a high number of projects relative to capacity, suggesting smaller-scale deployments.
• Arizona (AZ): 76 plants contribute 22.4 GW, indicating larger average project sizes compared to Massachusetts.
• New York (NY): 65 plants account for 1.5 GW, reflecting a moderate number of plants with lower individual capacities.

Leading Projects by Capacity

The battery storage fleet includes several exceptionally large projects, with the top facilities demonstrating multi-gigawatt capabilities. These projects significantly contribute to the overall installed capacity.

1. Hop Hill Solar Generation and BESS (WA): At 2,600 MW, this is the largest battery storage plant identified.
2. Pepper Hammock Solar and Storage (GA): This facility in Georgia ranks second with 2,500 MW.
3. Sunstone Solar (OR): Located in Oregon, it is the third-

The battery storage sector is experiencing strong investment and construction activity, yet faces growing regulatory and permitting challenges at local levels.

Development Momentum and Financial Commitments

• Recent news signals highlight significant construction starts, with Eolian beginning work on a 1.06 GWh Ohio BESS, noted as the largest system in PJM, and the 1+ GWh Flint Grid BESS near Columbus, Ohio.

• Project financing continues to flow into the sector, exemplified by Spearmint Energy securing nearly $450 million for a 600 MWh BESS.

Regulatory and Permitting Headwinds

• Regulatory constraints are emerging, including a notice of intent to prepare an environmental assessment by Green Mountain Power Corporation.

• Local permitting challenges are evident, with Johnstown considering a one-year battery moratorium and reports of at least one Virginia county banning battery storage.

While significant development and financial commitments underscore rapid growth in the battery storage sector, the rise in local permitting challenges and moratoriums suggests increasing scrutiny that could impact project timelines and deployment velocity.

The interconnection queue shows an overwhelming pipeline for battery storage, with proposed capacity more than doubling the current operational fleet, driven by a concentration of large-scale projects.

Battery Storage Dominates Development Pipeline

• The interconnection queue for battery storage currently includes 2,072 projects, representing a substantial 412.7 GW of proposed capacity.

• This pipeline capacity for battery projects significantly exceeds the 194.4 GW currently operational fleet capacity, indicating robust future growth.

• A large majority of these projects, 1,947, are listed as 'active', suggesting strong developer intent, while only 125 projects are marked as 'suspended'.

Concentration of Large-Scale Battery Projects

• The five largest proposed battery projects are all located in Oregon and are solely battery technology, totaling 9.3 GW of capacity.

• The largest single proposed project is a 3,600 MW battery facility in Oregon, followed by an 1,800 MW project, also in Oregon.

• Three additional projects in Oregon are each proposed at 1,300 MW, highlighting a concentration of very large-scale developments in a single state.