ENGIE strengthens the resilience of the Belgian electricity system with new flexible capacities

ENGIE is reaching major milestones for Belgium’s electricity security of supply—one of the Group’s historic markets—by commissioning and developing strategic infrastructures that enhance grid resilience and support 24/7 renewable energy integration.

Flémalle: a state-of-the-art gas-steam power plant
Selected during the first auction of the Belgian Capacity Remuneration Mechanism (CRM) in 2021, the Flémalle combined-cycle gas turbine plant (875 MW) is now available for the grid. Designed to keep emissions as low as possible and ultimately become CO₂-neutral, it will achieve an efficiency above 63%, making it one of the most efficient plants in the world. Thanks to its fast start-ups and modulation capability, the facility provides high flexibility to respond to demand fluctuations and supply more than one million households.

Vilvoorde: one of the largest battery storage projects in Europe
ENGIE has commissioned, two months ahead of schedule, its Battery Energy Storage System (BESS) in Vilvoorde, one of the largest in Europe. With a capacity of 200 MW / 800 MWh, BESS Vilvoorde can store and deliver for four hours the equivalent of the daily electricity consumption of nearly 100,000 households. An extension to 300 MW / 1,200 MWh is under study. With Vilvoorde, Kallo and Drogenbos, ENGIE will have 380 MW / 1.5 GWh of battery storage capacity installed in Belgium by 2027.

Coo: modernizing a historic infrastructure
A cornerstone of the Belgian electricity system for over fifty years, the Coo pumped-storage plant has been undergoing an extensive expansion and modernization program since 2021. Following the raising of the upper reservoir dams, works are continuing to increase capacity by 79 MW / 450 MWh, reaching a total output of 1.16 GW / 6.45 GWh, while extending the lifetime of the facility.

A European ambition
Beyond Belgium, ENGIE is accelerating the development of flexible assets across Europe. With 531 MW of BESS capacity in operation and under construction in Europe as of June 2025, the Group has since announced the construction of two battery projects in Romania (85 MW / 170 MWh) and the acquisition in Italy of three projects totalling 250 MW / 1 GWh. These initiatives support ENGIE’s global objective of reaching 95 GW of renewable and storage capacity by 2030.

“Flexibility is at the heart of the energy system. It plays a crucial role in maximizing the full potential of renewable energy around the clock and ensuring grid stability at all times. In Belgium and elsewhere, our strategy is built on complementarity: renewable generation, storage, and dispatchable assets to deliver a reliable, low-carbon, and competitive electricity system,” said Paulo Almirante, ENGIE Senior Executive Vice President in charge of Renewable and Flexible Power