Huge 4-Hour Battery Storage System with 2,000 MWh Planned in Germany: 500 MW Large-Scale Battery Storage Project to Be Presented to the Municipal Council
Bühl (Germany) – The market for large-scale battery energy storage systems is increasingly moving toward systems with longer discharge durations of around four hours. These storage systems can supply renewable electricity with a time shift and are considered an important building block for integrating wind and solar energy as well as stabilizing power grids.
Large-scale battery storage as an infrastructure component of the energy transition
The large-scale storage facility planned in Bühl is designed for an output of 500 megawatts (MW) and a storage capacity of 2,000 megawatt-hours (MWh). This makes the project one of the largest battery storage projects currently planned in Germany. The four-hour storage duration reflects a system design that is becoming increasingly common in the market, aimed at making electricity from wind and photovoltaic systems available over several hours and feeding it into the grid during peak demand periods.
Large-scale battery storage systems are increasingly taking over functions that were previously reserved for conventional gas-fired power plants. They compensate for weather-related and daily fluctuations in electricity generation and provide grid services. Due to their short implementation times and longer discharge durations, they reduce the need for flexible conventional power generation.
The site in Bühl was selected because of its proximity to the existing high-voltage infrastructure. According to the city of Bühl, this is intended to avoid additional transmission routes and reduce environmental impact.
Project partners develop BESS projects in the german market
Copenhagen Energy and Akaysha Energy have launched a cooperation for the joint development of battery energy storage system (BESS) projects in Germany. The project in Bühl is part of this development pipeline.
Copenhagen Energy is an internationally active developer of renewable energy projects and supports energy projects across the entire value chain – from early-stage planning to implementation. One focus area is the integration of flexibility solutions such as battery storage into existing energy systems.
Akaysha Energy specializes in the development, construction, and operation of large-scale battery storage systems. According to the company, its portfolio includes around 1,400 MWh in operation as well as a development pipeline of more than 30 GWh across Australia, Japan, and the United States. One reference project is the Waratah Super Battery (850 MW / 1,680 MWh) north of Sydney, Australia, which is considered one of the world’s most powerful grid-stabilization batteries.
The cooperation aims to advance the development of large-scale battery storage in the German market and combine complementary technical and project-related expertise.
Municipal involvement and economic prospects
For the city of Bühl, the project offers potential economic benefits, including possible business tax revenues and regional value creation effects. At the same time, the project will be reviewed as part of the standard approval and participation procedures, particularly with regard to environmental, agricultural, and emissions protection aspects.
During the municipal council meeting on May 20 in the Friedrichsbau, the technical, legal, and scheduling framework conditions will also be explained alongside the project presentation.
Conclusion and outlook
The project in Bühl is representative of the expansion of large-scale battery storage within the German energy system. With 500 MW of power output and a four-hour storage duration, the project joins a growing development pipeline. The further development of the large-scale battery storage market in Germany will depend in particular on approval and coordination processes at the municipal and regulatory levels.
Source: IWR Online, 19 May 2026
