Battery Storage up to 230 MWh: SEAC Group and Sunotec Launch Multi-Stage Large-Scale BESS Project in Germany
Munich/Münster (Germany) - Battery storage systems play a central role in increasing the flexibility and dispatchability of electricity generated from renewable energy sources. The market for large-scale battery storage is developing with increasing momentum. This is also confirmed by the new large-scale storage project between SEAC Group and Sunotec.
Project Launch with a Clear Roadmap Through 2028
SEAC Group has commissioned Sunotec Germany to implement the first construction phase of a large-scale battery storage program in Germany. SEAC Group acts as the client and project owner, while Sunotec Germany is responsible for the turnkey construction and maintenance of the facilities. Construction for the first phase of the project is scheduled to begin at the end of the first quarter of 2026.
The section now awarded marks the start of a multi-phase project with a planned total capacity of up to 230 MWh. In total, four construction phases are planned, to be implemented gradually and depending on project progress, market conditions, as well as regulatory and grid-related requirements. Full completion is scheduled for 2028.
Specifically, the first confirmed construction phase comprises a capacity of 20 MWh. An internal approval has already been granted for the second construction phase with an additional 20 MWh, with the contract award expected in the first quarter of 2026. The third phase, with a capacity of 30 MWh, has also received a positive internal assessment but remains subject to the conclusion of a final grid connection agreement. The fourth and largest expansion stage, with up to 160 MWh, is currently under review and depends on the results of grid compatibility studies.
“With the awarding of the first construction phase, we are setting an important milestone in the implementation of our storage strategy,” explains Abdelilah Zaafarane, CEO of SEAC Group. Sunotec brings the necessary experience for the turnkey realization and reliable operation of the facilities.
Sunotec Germany also emphasizes the long-term nature of the partnership. “We are pleased to implement the first construction phase of the battery storage projects for SEAC Group and to support the facilities throughout their entire lifecycle,” says Christian Salzeder, Managing Director of Sunotec Germany.
Battery Storage in Germany on a Record Growth Path
The project between SEAC Group and Sunotec aligns with the dynamic market development in Germany. Battery storage systems are increasingly regarded as a key building block of the energy transition, as they can store solar power, smooth generation profiles, and help support grid stability. Their economic value is increasing with growing volatility in electricity markets and rising grid congestion.
The expansion of battery storage accelerated significantly again in 2025, and Germany appears to be at the beginning of a rapid growth cycle that will increasingly establish battery storage as a central pillar of the energy transition. According to the Federal Network Agency’s Market Master Data Register, new storage systems with a capacity of around 7.7 GWh were commissioned in 2025. This represents an increase of 22 percent compared to 2024 (6.3 GWh).
As a result, the total battery storage capacity in Germany has risen to 26.6 GWh. Since 2020, growth in the storage market (2020: 0.91 GWh) has accelerated significantly. Key drivers include declining system costs, higher market volatility, and a growing need for flexibility in the power grid. Currently, the locations of the ten largest battery storage systems in Germany are in North Rhine–Westphalia, Brandenburg, Thuringia, Schleswig-Holstein, and Bavaria.
Source: IWR Online, 22 Jan 2026
