Energy storage systems company Stem raises $15m series B funding from investors including GE Ventures and Iberdrola, to back its expansion into the rapidly growing energy storage market.

Stem, a US-based energy storage systems company which makes lithium-ion battery devices connected to cloud analytics, has raised $15m series B funding from GE Ventures, the corporate venturing unit of industrial conglomerate GE, Spain-based energy company Iberdrola, and existing investor Angeleno Group, a clean energy-focused growth capital investment firm.

The series B funds will enable Stem to expand into to new commercial and industrial sectors and geographies.

Previously, in September 2011, Stem raised $10.2m series A funding from Angeleno Group…