LEAG Clean Power and Fluence have announced a joint venture to build the largest battery energy storage system (BESS) project in Europe with a 1 GW/4 GWh capacity in Janschwalde, Germany. The 1 GW battery storage project will use Fluence’s Smartstack platform. The Janschwalde battery storage project will be up against mega installations like the 700 MW/2800 MWh GIGA Green Turtle battery park in Belgium.
Factsheet for the Largest Battery Storage Project in Europe: GigaBattery Janschwalde 1000
Location: Janschwalde in Lusatia, Germany.
Developers: LEAG Clean Power and Fluence Energy
Capacity: 1 GW of power and 4 GWh of storage capacity.
Technology: Fluence Smartstack modular battery and PCS system.
Status: Final approvals and construction pending.
Estimated Timeline: Permitting in 2026. Construction through 2028.
Significance: Largest battery project in Europe. Also, a major milestone in Germany’s energy transition.
Timeline for the Largest Battery Storage Project in Europe
2024: LEAG’s GigawattFactory strategy publicly expanded. Large renewable and storage plan also announced.
November 2025: LEAG and Fluence partner for the largest battery storage system in Europe with 1 GW/4 GWh capacity to be built in Germany.
Q2 2026: Final permitting and planning expected.
2027-2028: Construction and commissioning of the storage facility.
Outlook on Europe’s Largest BESS in Germany by LEAG and Fluence
Germany’s transition from coal towards renewables creates a need for large scale battery systems to store excess wind and solar output. The battery systems are also going to be key in stabilizing the grid. They are also important for the reuse of existing infrastructure like transmission lines and brown coal power plant sites. Germany is also home to a 1 GW/2GWh battery storage installation by ADS-TEC that expects completion by mid-2026.
LEAG’s GigawattFactory initiative in Lusatia also proves to be an important regional transition program. The initiative aims to convert legacy coal sites into renewable hubs. These will incorporate wind, solar, hydrogen and storage projects. The 4 GWh battery project poised to be the largest in Europe is emblematic of this shift. It is expected to make scalability flexible, support higher renewable penetration and encourage industrial development in a former coal region.
The involvement of Fluence, who is a global leader in storage systems, also underscores the how batteries are becoming a cornerstone of Europe’s energy transition infrastructure.
