Thermal energy storage company Rondo Energy has completed a US$60 million fundraising round from investors including Rio Tinto, Microsoft, Aramco and Energy Impact Partners.

Utility Xcel Energy has received a US$20 million grant commitment from VC firm Breakthrough Energy for projects using Form Energy’s iron-air battery, while a sodium ion battery firm has secured bridge financing.

The past week has seen thermal energy storage solution companies strike or execute on commercial deals across Norway, Greece, Israel and South Africa.

Bill Gates-founded Breakthrough Energy, The European Associate for Storage of Energy (EASE), Solar Power Europe and Wind Europe have together called on the European Commission to recognise energy storage’s crucial role for the security of energy supply in Europe.

Breakthrough Energy Ventures was among investors in a Series C funding round for Reactive Technologies, a company which has developed a means to measure “fundamental grid stability parameters in real-time,” offering visibility to renewable energy and energy storage asset developers and system planners. 

Two startups seeking to disrupt the energy sector with novel long-duration energy storage technologies have formed partnerships with established industry players.