COO-Trois-Pont Pumped Storage

The Challenge

Increase the storage and power performance of the existing Coo pumped‑storage plant by 7.5% while safeguarding reliable operations for the next 40 years. The upgrade had to be conceived and delivered on a live, grid‑critical asset, balancing stringent technical, scheduling and regulatory requirements.

The Solution

Tractebel supported the modernization and capacity enhancement of the Coo 1 pumped-storage plant through a targeted upgrade of its key electromechanical equipment. The project increases the plant’s power output by 79 MW through the replacement of turbines, guide vanes, and transformers, as well as the adaptation of the generators across the three Coo 1 units. In parallel, Tractebel contributed to increasing the plant’s energy storage capacity by 450 MWh through the expansion of the upper reservoir, enabling greater operational flexibility and supporting the integration of renewable energy into the grid.

The Impact

The modernization of the Coo pumped-storage plant increases both its power output and energy storage capacity, enhancing Belgium’s ability to balance variable renewable generation and respond to fluctuations in electricity demand. By extending the operational lifetime of the facility by approximately 40 years, the project secures the long-term reliability of a strategic grid asset while delivering greater flexibility and resilience to the national power system.