Battery Storage
508.248 MW storage in Middlesex, MA · In queue since June 2021 · Proposed COD May 2028
508.248 MW
Capacity
1
Components
Battery
4y 11m
In Queue
IA Executed
IA Status
COD target: 2028
Total Duration
6y 11m
Interconnection request submitted to ISO/RTO
ISO-NE is transitioning to cluster studies per FERC Order 2023.
Typical: 25–30 months (recent)
Interconnection agreement executed — binding commitment to build
Typical: 30–60 days (negotiation)
Project under construction
Typical: 6–18 months
Proposed COD: 2028-05-31
The Battery Storage project is a proposed 508.25 MW battery storage development in Middlesex County, Massachusetts. It is located within the ISO-NE region and consists entirely of battery technology. The project entered the ISO-NE interconnection queue as queue ID ISO-NE-1143 on June 15, 2021, with a proposed commercial operation date of May 31, 2028. The interconnection agreement (IA) has been executed.
The project has been the subject of recent news coverage, with six articles focusing on deals and industry developments.
Generated from interconnection queue and public data sources
State
MA
County
Middlesex
Grid Region
ISO New England
Market
ISO/RTO Member
Developer
—
Utility
ISO-NE
Entity
ISO-NE
Service Type
—
Point of Interconnection
Mystic 345 kV between breaker 101, 106 and 107
Data Source
LBNL + Live
- ISO / RTO
- ISO-NE
- Trading Hub
- .H.INTERNAL_HUB
- Hub Confidence
- MEDIUM
This project's market context is estimated from its Point of Interconnection. Hub and node assignments are approximate and based on geographic inference from the POI substation name.
Last updated 2026-03-26
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