On-site energy solutions provider Calibrant Energy has turned on three front-of-the-meter battery energy storage systems (BESS) in New York in collaboration with CoreSite.

The BESS will provide 13.5MW, or 55.7MWh, of dispatchable capacity to the Con Edison grid in New York, and will be used by CoreSite and a leading hospital institution via Value of Distributed Energy Resources (VDER) credits.

Macquarie Asset Management portfolio company Calibrant Energy announced the energization on LinkedIn, noting that the BESS deployment will play "an important role in stabilizing the grid during peak summer demand—when electricity is most expensive and grid reliability is most critical."

The BESS deployments are located in Westchester County. According to Calibrant, they demonstrate a "novel commercial approach" and enable customers to enjoy the financial benefits of distributed energy without hosting infrastructure on-site.

The deployed battery systems were developed by New Leaf Energy, and are fully owned and operated by Calibrant.

“We’re proud to be a trusted partner in New York, delivering flexible grid assets that strengthen local communities,” said Phil Martin, CEO at Calibrant. “Limited physical space at some customer sites can make on-site energy solution infeasible. In this case, we delivered an off-site configuration that still drives meaningful savings—a testament to our ability to find and deliver significant value, no matter the circumstances.”

“CoreSite is pleased to collaborate with Calibrant through a long-term energy agreement that supports our energy management objectives while enhancing the reliability of the local electric grid serving our data centers in the New York area,” said Ben Garrard, VP of power and energy management at CoreSite.

CoreSite, part of American Tower, operates 30 data centers across the US. The company has one data center in New York, and two facilities across the New Jersey border in Secaucus. In late July 2025, CoreSite launched a data center in Santa Clara, which had been in the works for five years.

BESS, like UPSs, rely on batteries but are much larger - capable of scaling to the hundreds of megawatts and offering longer term storage durations of between two and six hours, or longer in some cases. Because of this, they are increasingly being used in grid balancing roles, and can also be tied to intermittent renewable assets.

BESS has been deployed in a myriad of ways across the data center sector. In 2023, Microsoft, in partnership with Saft, deployed a BESS system at its Stackbo data center in Sweden to displace the use of backup diesel generators. The system provides 16MWh of storage and provides 80 minutes of backup power.

Last year, Keppel announced it would install BESS systems at two of its Dublin data centers to improve power quality on site.

BESS is even being explored as a prime power option for data centers. Last year, Energy Vault partnered with RackScale Data Centers (RSDC) to deploy its proprietary B-Nest BESS at RSDC-operated data center sites. B-Nest is a modular multi-story structure designed to house stackable lithium-ion BESS units. The company claims the technology can store up to 1.6GWh per acre, providing data centers with full primary power for more than ten hours.

In June of this year, FlexGen and Rosendin signed an MoU to develop utility-scale BESS solutions for data centers.

DCD did a deep dive into the use of BESS within the data center sector in our latest magazine, available here.