Gresham House has completed the acquisition of Swiss-based energy transition investment manager SUSI Partners AG.
As a result, the company’s assets under management have reached £10.7 billion. Integrating SUSI Partners will also create a £2.7bn energy transition platform, something that was noted when Gresham announced it would acquire the business in September last year.
The newly created entity is now one of the ten largest investors in Europe’s energy transition.
Tony Dalwood, CEO of Gresham House, commented: “This transaction is a significant milestone for Gresham House, strengthening our leadership in the energy transition and significantly expanding our global capabilities.
When the merger was announcedThe companies said it combines Gresham House’s market leadership in the UK battery energy storage systems (BESS) market, through the Gresham House Energy Storage Fund (GRID), with SUSI’s equity and credit expertise in global energy transition infrastructure.
Now that the transaction has been completed and all required approvals have been obtained, all SUSI Partners employees have joined Gresham House.
It extends Gresham House’s reach across continental Europe and Asia. The announcement makes it clear that the existing SUSI strategies, including the Southeast Asia-focused strategy, will continue to be led by the current portfolio managers.
SUSI’s CEO Marco van Daele will take charge of the integrated Energy Transition division. Ben Guest, director of Gresham House, will continue to oversee the UK’s battery storage efforts, including the management of GRID.
In 2026, the platform will launch a new global energy storage strategy, a new private credit infrastructure strategy and an expansion of its Southeast Asia-focused energy transition strategy. Gresham House has also opened a new sales office in Frankfurt.
In November 2025, about a month after the SUSI merger was announced, GRID announced this The net asset value (NAV) in the third quarter was 7.4% higher than in the previous quarter. The fund’s operating assets are valued at an average of £706/MW operational capacity of the fund at the end of the third quarter the capacity was 1,072 MW/1,701 MWh.
Although SUSI was one of the pioneers in the UK BESS market and a joint venture (JV) with developer Eelpower to roll out seven UK projects, the focus is primarily on overseas (as reflected in the merger’s focus on expanding Gresham’s global reach).
