Trend Toward Long-Duration Storage: Eku Energy Enters German Market with 4-Hour Battery Storage System
London — Germany's battery storage market is shifting toward longer discharge durations, with new projects increasingly moving from the roughly two-hour standard toward four hours. The "Dion" battery storage project in Lamspringe is following this trend, marking the entry of British storage developer Eku Energy into the German market.
Acquisition of Nion's Project Company
Eku Energy acquired the project company behind the Dion storage facility from Hildesheim-based Nion Energieprojekte GmbH. Nion has spent several years developing regionally rooted energy projects in cooperation with landowners and municipalities. Alongside the sale, the two companies signed a development services agreement under which Nion will remain responsible for further project development until the facility is ready for construction, while Eku Energy takes strategic control of development, design and technology. Fluence, a long-standing supplier of lithium iron phosphate (LFP) batteries, is also involved in the project.
"Eku Energy’s core strength lies in combining technological expertise with deep commercialisation experience," said Erin Lee, Chief Financial Officer at Eku Energy. "In our multi-use projects, we combine long-term offtake agreements with the participation of our battery assets in power exchange markets. This expertise in contracts and storage technology delivers greater revenue resilience and visibility for our projects.”
Germany Strategy
With its entry into Germany, Eku Energy is expanding into its sixth global market, with the Lamspringe storage facility marking the first step. The London-based company was founded in 2022 by Macquarie Asset Management's Green Investment Group and has been jointly owned since 2023 by the British Columbia Investment Management Corporation (BCI), one of Canada's largest institutional investors, and a fund managed by Macquarie Asset Management (MAM).
According to the company, Eku Energy is currently developing storage projects with more than 25 GWh in Australia, Japan, New Zealand, the United Kingdom and Italy. For Germany, the company plans to build a long-term project pipeline and intends to open a German office in 2027. Eku Energy is seeking further partnerships along the energy value chain, particularly for storage projects and long-term power offtake and commercialisation models.
Trend Toward Multi-Hour Storage
Germany's battery storage market is structurally shifting toward larger capacities and longer discharge durations, driven mainly by significantly falling system and battery costs. Eku Energy's Dion project now joins this trend alongside projects by Swedish provider Flower Infrastructure Technologies in Hamburg-Bergedorf and in Döllnitz, Saxony-Anhalt, which are likewise designed for four-hour discharge durations.
Unlike short-duration systems designed for frequency regulation, multi-hour storage systems are increasingly focused on arbitrage trading, balancing fluctuations in generation, and integrating high shares of renewable energy — factors that raise the requirements for storage duration and flexibility.
At the same time, project sizes in Germany are also growing in terms of power output. In early July 2026, operator BW ESS began construction of a storage facility with 1,000 MW of power and up to 5,700 MWh of capacity in Klostermansfeld, Saxony-Anhalt — according to the company, the largest battery storage facility in Germany to date. The large-scale battery storage market is thus developing along two dimensions simultaneously: greater capacity per project and longer discharge durations.
Source: IWR Online, 15 Jul 2026
