Wärtsilä Begins Construction of a 50 MW / 100 MWh Energy Storage System to Bolster Grid Stability in Belgium

­Technology group Wärtsilä has been selected by Gramme Storage 1 to deliver a 50 MW / 100MWh battery energy storage system in central-eastern Belgium. Through the Gramme 1 project, Wärtsilä and Gramme Storage 1 will support Belgium’s transition toward a more sustainable, efficient, renewable energy system. Construction is now underway and the site is expected to be completed by Q2 2027. The order was booked in Q2 2025.

“This project with Wärtsilä underscores our commitment to dependable, flexible energy in Belgium”, said Guillaume Poncelet, Managing Director at Kallima Energies – the Liège based developer of the project. “This collaboration highlights the growing role of battery energy storage in supporting Belgium’s electricity system. By delivering essential ancillary services, the system will play a vital role in balancing the grid.”

Gramme 1 represents Wärtsilä’s first energy storage project participating in Belgium’s Capacity Remuneration Mechanism (CRM). This framework is designed to ensure Belgium’s energy supply security by enabling assets to deliver essential grid services such as frequency and voltage support that contribute to electricity system resilience and dependability.

“This project in partnership with Gramme Storage 1 reflects our shared focus on supporting Belgium’s energy security and grid stability during the transition to a more renewable power system,” said David Hebert, Vice President of Global Sales Management, Wärtsilä Energy Storage. “Wärtsilä’s advanced technology will enable the site to provide critical ancillary services that support a resilient, future-ready grid.”

Gramme 1 will utilise Wärtsilä's GridSolveTM Quantum2 energy storage system together with its control and optimisation software, GEMS, to deliver a standalone, fully integrated solution that enhances grid flexibility, reliability, and sustainability. Wärtsilä will also deliver the project under an engineered equipment delivery (EEQ) contract, with guaranteed asset performance under a separate long-term service agreement. With this project underway, Wärtsilä’s energy storage portfolio in Europe now exceeds 2.7 GWh.