German grid operator dispute limits battery use at new solar-storage hybrid plant

hybrid power plant combining 69 MW of solar generation with a 76.5 MWh battery has entered operation in Brandenburg, Germany, southeast of Löwenberg, after roughly four years of development, permitting, planning, financing and construction. Technical approval for grid feed-in was granted in mid-August, with an official opening scheduled for Sept. 25.

The battery storage system consists of 17 containers, each with 4.5 MWh of capacity. Fourteen are located within the solar park, while three sit at a dedicated substation built for the project, Bergsdorf-West.

MHB Montage GmbH, based in Merkendorf, installed the battery systems, while MHB Energie GmbH, based in Dessau-Roßlau, served as general contractor for the solar park. Phono Solar supplied the PV modules, Huawei supplied the inverters and battery storage systems, and Zimmermann PV-Steel Group supplied the mounting structures.

The project is operated by Solarpark Löwenberger Land Betriebs GmbH & Co. KG. Solarpark Verwaltung I GmbH owns 96% of the operating company, with the remaining 4% held by the Pfitzmann-Freese farming family.

The 69 MW solar plant is split into two sections. A 33.6 MW portion has been fully sold under Germany’s investment asset business (IAB) model, according to Tobias Bertenbreiter, managing director of the operating company, with Finanzkonzepte Deutschland (FKD) and Von Feder Gruppe acting as sales partners.

The remaining 35.4 MW is currently retained by the project company. Bertenbreiter told pv magazine that slightly more than half of that capacity will likely be sold under the same model in the near term, with the rest kept as a long-term asset.

The battery’s future operating model remains unresolved because of a dispute over grid import capacity. Bertenbreiter said local distribution network operator Eon Edis initially offered a connection agreement providing 6.8 MW of import capacity, split between 800 kW for the solar plant’s own consumption and the remainder for battery operations and commercialization. Three of the battery containers were positioned at the project’s substation specifically to support that planned arrangement.

Eon Edis subsequently withdrew the agreed import capacity, restricting the battery to storing only electricity generated by the co-located solar plant. Suena Energy is responsible for optimizing and marketing the battery, with project revenues used to refinance the investment, Bertenbreiter said. The project currently has no power purchase agreement or flexibility purchase agreement in place. The operating company has sent a letter from its lawyers to Eon Edis seeking to restore the battery’s import capacity.

If the import capacity is restored, the battery could also operate as a grid-charged storage system, expanding its potential revenue streams.