EXECUTIVE SUMMARY
German residential battery manufacturer sonnen GmbH has filed for insolvency following its acquisition by TIVEN, while sonnen USA reports doubled sales and tripled production. The restructuring affects its German operations, with customer support expected to continue. Meanwhile, the US business is expanding residential battery storage manufacturing and virtual power plant participation.
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German residential battery energy storage manufacturer sonnen GmbH has filed for insolvency, while its US subsidiary, sonnen USA, has reported significant growth in battery sales, manufacturing and virtual power plant (VPP) operations. The developments follow investment group TIVEN's acquisition of sonnen's global business from Shell approximately two months earlier.
According to Germany's Handelsblatt, sonnen GmbH confirmed its insolvency filing and informed approximately 400 employees at its headquarters in Wildpoldsried, Bavaria, on 22 October 2026. The restructuring is expected to involve substantial changes to the company's German operations, including the winding down of several subsidiaries or their entry into insolvency proceedings under self-administration.
The company reportedly plans to retain only one production facility, although the location has not been disclosed. Despite the restructuring, sonnen intends to continue providing services to its existing customer base of more than 150,000 customers. Further clarification regarding long-term battery maintenance, software support and service arrangements remains necessary.
In contrast, sonnen USA has announced strong growth across its residential battery storage business. The company reported that sales doubled and production tripled year over year, supported by expanded manufacturing operations at its Stone Mountain facility in Georgia. It expects to deliver more than 180 MWh of residential battery storage during 2026.
Virtual power plant participation has contributed to this expansion. VPP technology enables distributed residential battery systems to operate collectively, supporting electricity grid management while creating additional value opportunities for homeowners with solar and storage installations.
In Texas, sonnen's SOLRITE offering serves more than 6,000 homes, integrating rooftop solar generation, battery storage, energy management and VPP participation. The company also operates its sonnenCommunity program in Massachusetts, offering cash rewards to participating homeowners within National Grid and Eversource service territories.
Additionally, sonnen reported increasing sales through its Wattsmart program in Utah, reflecting continued activity in residential battery storage and grid-connected energy management.
TIVEN acquired sonnen's entire global business, including its US operations. sonnen USA CEO Blake Richetta stated that the investment group remains committed to supporting the company's long-term development in North America's VPP market. TIVEN also expressed its intention to strengthen the company's growth.
However, sonnen USA's announcement did not address the German insolvency proceedings. The company also declined to comment on developments in Germany when contacted by pv magazine. The implications for manufacturing continuity, software services and customer support across the wider business remain unclear.