Calibrant closes $145M debt facility for solar and storage

Calibrant Energy has begun site mobilization for a 120-megawatt-hour battery storage project serving a hyperscale data center customer in PJM. The money behind it closed on November 10: Calibrant, the on-site energy developer backed by Macquarie Asset Management, announced a $145 million debt facility led by Investec, with Citi, Liberty Bank and Siemens Financial Services also participating. The facility covers solar and battery storage projects across several U.S. power markets, according to the company's announcement, which POWER and North American Clean Energy carried.

The battery is the part worth studying. Calibrant says it is designed to give the data center more control over how and when it pulls power from the grid. That matters in PJM, the regional electricity market spanning parts of the Mid-Atlantic and Midwest, where PJM and federal regulators are still working out how very large electricity users connect to a grid with limited room. For the person who signs a data center's power deals, this deal tests whether that flexibility can be bought as a service and financed by banks instead of built on the owner's books.

How a battery shortens the wait for power

citybiz, which covered the close, explained the reasoning. A data center that manages its demand with on-site storage can cut its peak power requirement, shrink the transmission and distribution upgrades the utility would otherwise have to make, and improve its chances of getting new capacity connected. Calibrant's announcement, carried by POWER Magazine, said this flexibility helps projects interconnect more quickly. The company added that it lowers the need for expensive upgrades to grid infrastructure, a cost that would otherwise fall on other ratepayers.

The stakes are not abstract. Hyperscale data centers support cloud computing and AI infrastructure and need large amounts of reliable electricity, and citybiz noted that delays in securing grid connections and the cost of required upgrades have become significant considerations for the developers and operators building them.

The "grid citizen" phrasing ties back to the ratepayer argument. If flexibility avoids upgrades that other customers would otherwise fund, the battery becomes part of the case for connecting a very large load at all, rather than only a speed play for the owner. Martin went further, saying the financial close and site mobilization show large-load flexibility is "not just possible but a commercial reality today."

According to Energy-Storage.news, Aligned Data Centers called an earlier Calibrant battery project at its Pacific Northwest campus "first-of-its-kind." The company said it would mark the first US case of a battery system designed specifically to speed up interconnection and get a large-scale data centre up and running. Calibrant announced that project in October 2025, roughly a year before the PJM close.

Calibrant chief commercial officer Matt Barnes told Energy-Storage.news Premium that the building was already finished but faced a wait for utility power that could have run years. He said the delay stemmed from the facility's load during peak hours, and that the battery would let the utility, PGE, serve the customer on a faster timeline by making the data center "a more flexible form of load."

The building was ready. The grid's peak hours were the problem. For operators in a similar position, the case suggests storage could help a finished facility get connected sooner, because it targets the specific hours that held up the utility's ability to serve it.

The difference between the two cases is the market. Aligned's battery answered one utility's peak-hour constraint in the Pacific Northwest. The PJM battery enters a multi-state market where the rules for connecting large loads are still in motion, which makes it a broader test of whether the approach travels.

Inside the $145 million package

The facility does two jobs. According to IndexBox, it refinances assets already in operation and also provides capital for new construction. So the new data center battery, still in site mobilization, sits in the same facility as assets with an operating history. Calibrant has not named the hyperscale customer, the project locations, or the facility's interest rate and maturity, citybiz noted.

Investec's lead role came with its own statement. Fred Petit, co-head of Energy & Infrastructure North America at Investec, said the bank was proud to support Calibrant and Macquarie and valued the chance to provide financing for "the critical infrastructure needed to meet growing power demand across the U.S." IndexBox notes that Investec Bank plc is the banking subsidiary of Investec plc, a FTSE 100 listed company.

For the customer, the ownership model is the practical point. Calibrant develops, finances, owns and operates the on-site equipment, so the business using it skips the initial capital outlay; the company markets this as turnkey and zero-capex. For operators that would rather put capital into buildings and compute than into grid equipment, the battery arrives as a service contract instead of a line in the capital budget.

Energy-Storage.news describes Calibrant as an energy-as-a-service platform. The company's own announcement attributes its growth partly to customers' preference for an experienced partner that can develop, own and operate these systems, which puts the bank debt underneath that promise rather than on the customer's balance sheet.

Read those totals carefully. They fold in projects held under exclusive development agreements, so they describe a pipeline as much as a fleet. Calibrant's development portfolio also includes additional battery storage sites associated with the same hyperscale data center customer. For buyers weighing the model, a customer coming back for more sites could say more than any gigawatt total.

Batteries or engines on the data center site

The same Energy Storage News report covered Energy Vault's $137.5 million senior secured credit facility from Eagle Point Credit Management, announced October 29, to buy 275MW of reciprocating engine generation using Rolls-Royce MTU technology for hyperscale AI and data center projects. Equipment deliveries are expected from the second half of 2027 through the first half of 2028.

Energy Vault is not a pure engine play, though. In August it announced it would supply grid-forming BESS, power conversion systems and AI infrastructure control software to an undisclosed data center customer, an agreement it expects to generate roughly $500 million to $600 million in revenue across the second half of 2026 and 2027. In September it acquired a 15-project BESS portfolio of more than 2.3GW from Goshe Energy Storage, supported by a $40 million credit facility commitment from S2G Investments.

The company made headlines around 2019 with gravity-based storage, listed on the NYSE in 2022, and has since pivoted to BESS integration and build-own-operate development. That is the same broad ownership model Calibrant sells, which makes the two financings a useful pair: similar business structure, different hardware answers to the same power problem.

A battery reshapes when a site draws grid power; it still depends on a grid that can serve the facility most of the time. For operators whose utility can serve them outside peak hours, the Aligned case suggests storage could be a faster route to power. For sites where the grid cannot supply enough power, on-site generation such as Energy Vault's engines could be another option. Energy Vault's own mix of batteries and engines suggests the choice is not either-or at the developer level.

A Research and Markets report published in October projects the global data center energy storage market growing from $5.17 billion in 2026 to $10.48 billion by 2032, a 12.5% compound annual rate, with peak shaving and load management expected to be the second-largest application. The same report names high upfront capital as a notable restraint, which is the cost a third-party owner like Calibrant takes on.

The report also says grid constraints in established data center hubs are encouraging operators to strengthen on-site power infrastructure. It lists the other jobs storage does at these sites, from extended backup alongside UPS systems and power quality conditioning to renewable integration and black start, and flags integration with existing data center infrastructure, along with safety and thermal management, as challenges.

Questions for the team buying power

For a data center energy or development lead weighing a similar arrangement, the Aligned and PJM projects suggest where to focus the diligence:

• How many megawatts of peak reduction does the battery deliver, for how many hours, and will the utility count it in the interconnection study?
• Who owns, operates and finances the system, and what does the service contract commit the site to over its life?
• Which grid upgrades does the flexibility avoid, and would those costs have landed on the project or on other ratepayers?
• How will the system integrate with the site's existing power infrastructure, and who handles safety and thermal management?

The next signal is the follow-on work. If Calibrant's additional sites for the same hyperscale customer move from development into construction while PJM and federal regulators work through how large power users connect, that could suggest buying batteries to speed up connections is moving beyond first-of-its-kind projects.