With a capacity of 100 MWh and 40 lithium-ion battery units, the Deux-Acren energy storage facility stabilises the Belgian electricity grid by adjusting transmission frequency in real time.
Thanks to this facility, energy produced during solar or wind generation peaks can be stored and then reinjected during periods of high demand, thereby strengthening the country’s security of supply.
An industrial brownfield transformed into future-ready energy infrastructure
Built on the site of a former 25 MW oil-fired thermal power plant, this industrial brownfield has been fully rehabilitated to host a next-generation energy storage installation.
Beyond its technical advantages, the Deux-Acren energy storage facility is a cornerstone of the European energy transition. By reducing reliance on fossil-fuelled thermal power plants, it directly contributes to lower CO₂ emissions and to Europe’s energy sovereignty.
Commissioned in 2022, it became, at the time of its inauguration, the largest energy storage facility in continental Europe, demonstrating that large-scale battery deployment is now a reliable, fast-to-build and sustainable solution.
A vital role in grid stability
Energy storage ensures the continuous balance between electricity generation and consumption — a role historically fulfilled by oil- or gas-fired power plants, but now increasingly delivered by more sustainable and significantly more responsive solutions.
The batteries at the Deux-Acren facility can adjust grid frequency within fractions of a second, providing an essential service to maintain a stable and secure electricity supply.
The facility fulfils several key functions: stabilising the Belgian grid frequency, storing surplus renewable electricity generated during solar or wind peaks, and reinjecting energy when demand rises.
By replacing thermal power plants traditionally used for grid balancing, it reduces dependence on fossil fuels and accelerates the integration of renewable energy into the electricity mix.
A benchmark model for Europe
This project represents a major milestone for both Belgium and the European Union.
Developed in collaboration with Tesla, InnoVent and aggregator Yuso, it demonstrates the operational reliability and economic viability of large-scale energy storage solutions.
Financed without public subsidies, it confirms that an electricity system based on renewable energy combined with storage is not only possible, but already underway.
Revitalising a former industrial site
The dismantling of the former thermal power plant made it possible to remediate the site and replace a polluting technology with a modern, quiet and low-impact infrastructure. This reconversion addresses the challenge of reusing industrial brownfields — a key lever in limiting land take and soil artificialisation.
This project represents a major milestone in the development of electricity storage solutions in Europe. By demonstrating that large-scale batteries are economically viable, we show that it is possible to build a world based on renewable energy combined with storage. With Deux-Acren, we are helping regions to harness their natural resources and achieve energy sovereignty.
