Iron Mountain is installing a 23 megawatt-hour energy storage system at its New Jersey data center to reduce its reliance on the local electric grid and cut greenhouse gas emissions generated by the site.

The system, scheduled to be switched on before the end of 2026, uses standard lithium-ion batteries from Tesla. It will be integrated with an existing 7.2-megawatt rooftop solar array installed about six years ago, but Iron Mountain expects to manage the installations separately.

The primary justification for both investments is to improve the reliability of Iron Mountain’s power supply, along with electricity cost reductions when there’s increased demand on the local grid and large customers are asked to conserve power.

“The battery just creates economic value because it is getting paid by the grid to do frequency support, as an example, or it’s reducing our peak load on the grid during those critical grid times,” said Chris Pennington, senior director of energy and sustainability at Iron Mountain. “If it couldn’t do something that was worth money, then we wouldn’t be doing it.”

Utilities often switch on natural gas systems to handle increased electricity demand, and energy storage provides a lower-carbon option. Practically speaking, at least some of the power stored on the batteries was originally generated by fossil fuels, but peak demand is when the dirtiest sources are put into service, he said. 

No capital expense

Iron Mountain contracted with service provider Calibrant Energy to handle the project. It essentially rents the system, so the costs are included as part of Iron Mountain’s operations budget for the facility.

Calibrant has a similar relationship with another data center company, Aligned, for a larger storage system at an artificial intelligence facility in the Pacific Northwest. Google is using a variety of contracts to add energy storage at its sites, with the goal of more projects forward more quickly.

Energy storage installations at commercial and industrial sites grew 8 percent in 2025, on a per-megawatt-hour basis, according to new data from research firm Wood Mackenzie. The motivation for these companies is the same as Iron Mountain’s: access to a reliable, lower-carbon electricity supply.

Planning considerations

Iron Mountain has been talking about energy storage investments with Calibrant since 2023. It spent nine months evaluating projects before New Jersey’s energy storage incentives sealed the deal. Permitting took another nine months, and Iron Mountain expects to break ground in June.

The company’s facilities engineers and operations team at the site were consulted closely during planning, so they could assess potential risks to existing electrical systems. Iron Mountain’s finance team was also involved in the assessment, including how the installation would affect Iron Mountain’s insurance coverage.

The local community had a hand in choosing where the batteries are being placed. The site, which was a New York Times publishing facility before being converted in 2011, abuts a residential community. To minimize the impact on locals, Iron Mountain is using about a dozen spots in the existing parking lot to construct the system.

Iron Mountain is already designing its next potential energy storage installation in collaboration with Calibrant. It is likely to be in Virginia, where the company is part of a $10.5 billion grant program created by the Department of Energy in 2024. There, too, the focus is on improving electric grid flexibility.   

“The economics at every site will be a little different,” Pennington said. “And it’s important that there are market conditions that exist that enable batteries to step in and solve challenges, solve problems more cost-effectively than the way they’re being solved today.”