SUSI Partners has made its first investment in the US with the acquisition of a 50% stake in a portfolio of battery storage systems from Macquarie’s specialist green energy investment business.

The Swiss fund manager, through its SUSI Energy Storage Fund, is paying an undisclosed amount for the stake in the California-based portfolio of lithium-ion battery projects from Green Investment Group.

The diversified portfolio has a total storage capacity of 340MWh and comprises over 90 individual battery storage assets.

The portfolio was originally developed by AMS, a local developer who will continue to manage and dispatch the assets.

Marco van Daele, CIO at SUSI Partners, said: “This is SUSI’s first investment in the US, one of the most mature markets for energy storage globally.”

The State of California is formally pursuing a target of 100% carbon-free electricity by 2045 and is thus one of the trailblazers for the energy transition, Van Daele said.

“We are thrilled with this transaction in light of the role the portfolio has as a critical enabler of California’s long-term energy transition policy and look forward to continue investing in the US market.”

Gustavo Coito, investment director at SUSI Partners and transaction lead for this investment, said: “This transaction marks an important milestone for us and the SUSI Energy Storage Fund.

“This sizeable and mostly contracted portfolio is a perfect example of the infrastructure investment opportunities that exist in this market, which we expect will grow further significantly, and reflects SUSI’s core mission of financing the energy transition.”

Rob Kupchak, Macquarie Capital senior managing director and head infrastructure and energy in the Americas, said: “The Green Investment Group is focused on investing capital into development and construction of new Green Energy Infrastructure.

“As our portfolio reaches a more mature stage with projects entering the operational phase, we are delighted to bring in SUSI as a partner.”