Fluence and LEAG move forward with plans for a 1 GW / 4 GWh battery complex in Europe

Energy
December 6, 2025 · 8:40 PM3 min read

The future of storing power in the European region is about to get its most ambitious undertaking to date, as two giant players in the sector plan to transform the power grid on the continent. The latest alliance between Fluence Energy and LEAG Clean Power signifies much more than merely having another source of sustainable power in the European region; it symbolizes a paradigm shift in how the power requirements in the continent are treated.

GigaBattery Jänschwalde 1000 sets new European standards

LEAG Südfenster and LEAG itself are investing in the construction of what will be the largest battery storage in Europe, corresponding to 1 GW in power and 4 GWh in capacity. It will be implemented in Jänschwalde, Germany, using the innovative Smartstack™ battery storage technology developed by Fluence Energy, which marks the largest individual battery storage contract in the company’s history.

The GigaBattery Jänschwalde 1000 scheme is part of the overall GigawattFactory initiative developed by LEAG, which ensures the integration of solar power and wind farm solutions with flexible power stations and storage facilities. In fact, the availability of power irrespective of weather conditions has long remained an issue in the area of renewable power sources. The four-hour storage facility ensures optimal use of the grid connection.

Strategic partnership leverages complementary expertise and technology

To this historic cooperation, Fluence can contribute many years of global know-how in intelligent energy storage solutions, services, and optimization software. An impressive list of successfully contracted, implemented, and delivered gigawatts can already be ticked off in close to 50 global markets. Also, the strong in-country expertise in Germany makes the company an ideal partner in helping LEAG fulfill its ambitious vision.

LEAG Clean Power is part of Germany’s second-largest power company and second-largest private employer in eastern Germany, thereby tapping into in-depth knowledge of the region and its infrastructure. The company concentrates its portfolio on battery storage and innovative power plants and accelerates the change from traditional energy supply to future-oriented energy transition projects. Their GigawattFactory concept embodies an all-encompassing roadmap towards the integration of different power technologies in several locations in Germany.

Technical design optimizes grid integration and operational efficiency

The four-hour storage design of the project allows optimal usage of the already existing grid connections while at the same time playing an essential role in the stabilisation of the power grid in Germany, increasingly relying on renewables. Maximization of efficiency through reliance on the existing grid connections, rather than laying new ones, is the main idea of the technology applied in the construction of the facility.

German government support reinforces energy storage importance

The government in Germany has reiterated the importance of energy storage in achieving a secure, affordable, and sustainable power supply and has thus provided policy support to large-scale projects such as GigaBattery Jänschwalde 1000. Government support ensures conducive environments for private sector investment in the construction of such energy-infrastructure projects, and hence the government’s dedication to climate target success through innovation.

“We are honored to collaborate in such a large-scale and significant project and congratulate LEAG Clean Power on achieving such an important milestone for the future of the energy landscape in Germany and in Europe. It shows that when know-how, vision, and boldness come together, fundamental change is possible.” Julian Nebreda, President & CEO, Fluence

The collaboration between Fluence and LEAG is historic in the development of the European energy infrastructure, where technology and knowledge from the region come together to offer historic storage capacity. This new technology sets the pace in terms of storing energy at the grid scale level and can help faster the adoption of sustainable power through collaboration. The GigaBattery Jänschwalde 1000 Project will help in setting up future large-scale storage in Europe and other parts of the world.