Macquarie’s Green Investment Group sold the stake for an undisclosed sum. : 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.