US-based energy optimisation service provider Stem closed the $12m first tranche of its series C round today, with the tranche led by diversified conglomerate Mitsui.

Founded in 2009 as Powergetics, Stem has developed an energy storage system linked to a cloud-based big data and predictive analytics platform that enables businesses to store energy on-site and source it at off-peak times, reducing their electricity costs in the process.

The company plans to use the funding to further develop its technology and…