Plus Power energises 150-MW Cranberry Point battery in New England

• Plus Power’s 150-MW/300-MWh Cranberry Point battery in Carver, MA—New England’s largest standalone BESS—is online, supporting ISO-NE capacity and Clean Peak goals.

Plus Power has placed its 150-MW/300-MWh Cranberry Point Energy Storage facility into commercial operation in Carver, Massachusetts, now the largest standalone battery on the New England grid. The plant consists of 82 Tesla Megapack 2 XL units and holds a Capacity Supply Obligation with ISO-NE, committing the project to provide firm capacity into the regional market. It also participates in Massachusetts’ Clean Peak Standard program.

Beyond capacity, the asset time-shifts surplus energy into evening peaks and delivers fast-acting ancillary services, a growing need as the region integrates more intermittent renewables and faces higher loads from data-centre growth and electrification. During a June 24 heat wave—the region’s highest demand day since 2013—Cranberry Point supported the system amid a scarcity event, underscoring storage’s role in maintaining reliability and moderating price spikes. 

The project interconnects via a substation on a north-south transmission corridor that feeds demand centres around Boston, positioning the battery to respond where grid stress is acute. Plus Power notes the system helps Massachusetts advance its target of 1,000 MWh of storage by 2025; at 300 MWh, Cranberry Point accounts for a substantial share of that goal.

Commissioned on a relatively compact footprint compared with conventional generation, the project illustrates how standalone batteries can be sited near load and integrated into transmission-constrained areas to improve resilience. With New England coal and oil units retiring and extreme-weather events intensifying, flexible storage capacity is increasingly central to regional planning and market design.