Activate Capital led the round's first close, Stem's previous investors including General Electric, Total, Iberdrola, Exelon, Mitsui and RWE.

Stem, a US-based energy storage system provider that counts a host of corporates as investors, secured $80m yesterday for the first close of its series D round.

Growth equity firm Activate Capital led the tranche, investing together with Singaporean government-owned investment firm Temasek and Ontario Teachers’ Pension Plan, which took part the day after Canada Pension Plan Investment Board bought a $144m stake in renewables developer ReNew Power.

Stem develops and produces artificial intelligence-equipped, battery-based energy storage systems that…