Battery Storage in Germany Enters Gigawatt Class as BW ESS Breaks Ground on 1-GW Battery Project
Klostermansfeld/Zurich — BW ESS has broken ground on a 1,000 MW battery storage system in Saxony-Anhalt, Germany, marking the start of construction on the country's largest battery storage project to date.
1,000-MW Storage System to Strengthen Key Grid Node in Saxony-Anhalt
The battery system will connect to the grid via the nearby Klostermansfeld substation, a key node in Germany's extra-high-voltage transmission network. The storage facility is designed to absorb surplus electricity from renewable sources, offset peak loads and contribute to grid stability.
“We’ve made a long-term commitment to help realise the potential of energy storage in Germany and Klostermansfeld BESS will be our first German asset to enter construction,” said Roberto Jiménez, Executive Director of BW ESS.
German Storage Market Expands Rapidly in First Half of 2026
Germany's battery storage market is expanding rapidly in 2026. According to data from the Marktstammdatenregister at the Bundesnetzagentur (as of June 27, 2026), around 2,250 MW of battery storage capacity with more than 5,100 MWh of storage capacity was newly commissioned in Germany in the first half of 2026.
The planned 1,000 MW BW ESS system alone corresponds to nearly half of the battery capacity additions registered in Germany during that period. With a storage capacity of up to 5,700 MWh, the project has a discharge duration of around 5.7 hours at full output of 1,000 MW — a range previously achieved mainly by pumped-hydro storage plants. The project illustrates how battery storage systems are increasingly moving into capacity ranges that were previously the domain of conventional large-scale storage.
The Klostermansfeld facility exemplifies the expanding role of large battery systems in the power market. Beyond storing electricity, such systems are increasingly used as flexibility assets to help integrate renewable energy, offset peak loads and stabilize the power grid.
Large-Scale Batteries Help Smooth Power Prices
The growing deployment of large battery storage systems is creating additional ways to make use of renewable energy surpluses, helping to reduce price spikes on the power market. Large batteries also add flexibility during extreme situations such as prolonged heat waves, when thermal power plants may have reduced availability due to high temperatures or limited cooling capacity while electricity demand rises because of increased use of cooling equipment. In such cases, storage systems can offset short-term generation gaps.
By supplying electricity during periods of high demand, battery storage systems help ease morning and evening peak loads, contributing to smoother price fluctuations and a more stable power system.
Fewer Operating Hours for Costly Fossil-Fuel Plants
In addition to their impact on the power market, large-scale storage systems are changing the role of conventional power plants. During periods of high demand or low renewable output, battery storage can supply power on short notice, reducing the operating hours of peak-load power plants.
This particularly affects costly fossil-fuel plants such as gas-fired power plants, which have traditionally been used when additional capacity is needed at short notice. As large battery storage capacity expands, storage systems are expected to take over part of this flexibility function in the future.
Battery storage is thus becoming an increasingly important component of a power system with a growing share of renewable energy. The 1,000 MW BW ESS project reflects the broader shift toward large-scale, commercially significant storage facilities in the German storage market.
Source: IWR Online, 02 Jul 2026
