Alpiq acquires 103 MW/238 MWh BESS from Eco Stor

Alpiq has acquired Eco Power One GmbH, the project company behind the Bollingstedt BESS in Schleswig-Holstein, Germany, from Eco Stor. The companies did not disclose the purchase price. Eco Stor will remain responsible for the technical and operational management of the 103 MW/238 MWh battery.

The utility-scale battery has been operational since June 2025. Eco Stor said it developed one of Germany’s first flexible connection agreements (FCAs) for battery storage with grid operator Schleswig-Holstein Netz (SH Netz). The grid connection concept is designed to allow the battery to operate according to the network capacity available at any given time.

Based on this approach, Eon has announced plans to roll out a standard FCA across all of its distribution network operators in Germany by the end of the year. However, Eon told pv magazine that this will not be a single agreement with uniform parameters, but rather an arrangement that also takes regional specificities into account.

Eco Stor said the sale demonstrates that operating, marketing and grid connection concepts are becoming increasingly important in valuing battery storage projects, alongside installed capacity. “The Flexible Connection Agreement creates a reliable framework for operating the battery,” said Eco Stor CFO Jörn Rohland.

The company said Alpiq’s acquisition confirms this approach and reflects the increasing maturity of Germany’s battery storage market. It added that the transaction shows that predictability and grid-supportive operation do not have to be mutually exclusive when developing large-scale battery storage projects.

The transaction builds on an existing relationship between Alpiq and Eco Stor. At the end of 2025, the companies announced a cooperation on the Schuby battery storage project, where they signed a tolling agreement. With the Bollingstedt acquisition, Alpiq is now expanding its cooperation with the storage developer. Eco Stor said it will also use its experience from the ongoing technical operation of the Bollingstedt battery in developing further utility-scale storage projects.

From pv magazine Deutschland