A 900 MW battery storage project is being planned at the former Isar 2 nuclear power station in Bavaria, Germany, with the state government highlighting the site’s existing grid infrastructure as a key advantage, according to a report by Clean Energy Wire.
Munich-based investment firm Advisum is developing the project at Niederaichbach, where a substation is being expanded to accommodate electricity transported through the SuedOstLink transmission connection. The underground link is being built to move renewable electricity from northern Germany towards major demand centres in the south.
Bavaria’s economy minister Hubert Aiwanger described the proposed battery facility as an important element of the state’s energy transition. He said the location could help manage periods of high solar generation, when output can exceed local grid demand and create network constraints.
The planned storage facility would be significantly larger than most existing battery projects in Germany. The country added more than 2 GWh of storage capacity during the first quarter of 2026, bringing total installed capacity to around 30 GWh. Large-scale storage capacity increased by 290% year on year during the quarter, reaching about 6 GWh.
According to the Bavarian authorities, around 1,300 large battery projects are currently connected to Germany’s transmission and distribution networks.
The Isar 2 site could offer further opportunities for grid-connected infrastructure. Its existing substation is being expanded, with scope for additional connections for battery storage and other facilities. Advisum is also planning a 100 MW data centre at the location, adding another potentially large electricity consumer to the site.
The proposed development illustrates how former power station sites can be repurposed as Germany transitions away from conventional generation. Germany completed its nuclear phase-out in 2023, and the dismantling of the remaining plant infrastructure is continuing.
For Bavaria, combining storage with existing transmission infrastructure could help address the changing flow of electricity as solar and wind generation expand. Batteries can absorb surplus generation and discharge during periods of higher demand, reducing pressure on local networks and providing additional flexibility.
The 900 MW project remains at the planning stage, with further development dependent on cooperation between the developer, municipalities and relevant infrastructure operators.
