German start-up Sonnen Group has rolled out it lithium ion-based sonnenBatterie smart energy management home system, which the company describes as a smart power system for renewable energy. Through its sonnenCommunity, homeowners throughout Germany can produce, store and share their own electricity. The latest development, sonnenFlat, allows thousands of sonnenBatteries to be aggregated into one large storage pool as a virtual power station.

The sonnenbatterie provides an AC output of 3kW to 8kW from 4kWh to 16kWh storage in 2kWh steps and is guaranteed for 10,000 cycles or 10 years. The power management software stores excess energy from a renewable source such as a photovoltaic array or wind turbine and switches over to the battery to maintain a constant supply.

Recently, the start-up raised ₹569.97 crore ($85 million) from new and existing investors to expand the development of new products such as sonnenCommunity and further expansion in the U.S., Australia, UK and Italy.

The investment includes two new backers, Envision Energy and Thomas Putter, former CEO and ex-Chairman of Allianz Capital Partners and a leading investor in renewable energy technology, joining existing investors that include eCAPITAL, MVP, SET Ventures, Inven Capital and GE Ventures.

"We want to become the energy supplier of the future, and fast growth and leadership in innovation are the keys to reaching this goal," said Christoph Ostermann, CEO of sonnen Group. "With Envision Energy, we have gained a strategic investor who shares our vision, supplements our technology and has a strong presence in both the US and Asian markets."

In addition to its high-quality wind turbines, Envision Energy also develops software for decentralized energy sources and devices. Envision is represented worldwide and maintains numerous research and development centres in Asia, Europe and the US, including Silicon Valley, Houston, Texas and Boulder, Colorado.

The Sonnen Group was listed in the top 50 companies by MIT in early October, one of only two German companies in the list. "MIT has added Sonnen into the mix with companies like IBM and Bosch, acknowledging the innovative power of storing and managing the sun in a unique way," says Philipp Schröder, Chief Sales and Marketing Officer of Sonnen.