sonnen GmbH has reportedly filed for insolvency, less than two months after its acquisition by TIVEN
The German company plans to continue operating one production site and serving more than 150,000 customers
Meanwhile, sonnen USA reported doubled sales and tripled production output year-on-year
Less than two months after the investment firm TIVEN's family office took ownership, sonnen GmbH has reportedly filed for insolvency. The decision will affect nearly 400 employees at the German residential energy storage system (ESS) manufacturer and supplier. Meanwhile, sonnen USA has announced plans to expand.
German business daily Handelsblatt said the company has confirmed the development, saying that the German battery company officially filed for insolvency on October 22, 2026. It plans to liquidate several of its subsidiaries or place them under self-administered insolvency. According to the report, the German manufacturer had been ‘burning through money like crazy’.
sonnen GmbH will continue to operate a single production site while continuing existing business and services for its more than 150,000 customers.
The news follows sonnen’s sale by global oil and energy giant Shell plc to TIVEN in August 2026, three years after it put the company up for sale. TIVEN had been planning to restructure the business before reselling it (see Shell Sells sonnen To Tiven In Major Storage Deal).
Earlier, Enersol, a German subsidiary of sonnen, shut down its operations in 2024 citing lack of demand for solar and storage in Germany as one of the reasons (see Yet Another German Solar Company Going Down).
Meanwhile, sonnen USA says it doubled sales and tripled production output year-on-year (YoY) and expanded its manufacturing capabilities in Stone Mountain, Georgia, following strategic VPP partnerships with SOLRITE in Texas, New England, California, and other emerging markets.
Under TIVEN's ownership, sonnen USA plans to deliver more than 180 MWh of residential energy storage by 2026. “TIVEN is firmly committed to the long-term success of sonnen USA as a strong, market-leading company in the North American VPP energy market,” stated sonnen USA CEO Blake Richetta.
TIVEN also pledged support for sonnen saying, “The North American market for residential VPP solutions is significant, and we are pleased to enter it with sonnen, a true pioneer of the sector.”
sonnen GmbH’s reported insolvency follows similar decisions taken by several solar and storage companies calling it quits over the last two years (Bosswerk in 2024 and BSH GmbH & Co. KG in September 2026) as financial woes mount (see Solar Installer BSH GmbH & Co. KG Files For Insolvency).
Even ENERPARC, with close to 5.5 GW of installed capacity and a €1 billion financing announced in March 2026, filed for insolvency proceedings (see Germany’s ENERPARC AG Files For Insolvency In Hamburg).
Bloomberg attributes the situation to higher borrowing costs and weaker returns on new projects, which are worsening project economics, a situation that’s weighing on the industry across Europe, it added.
