Coo-Trois-Ponts Hydroelectric Power Station

The Mission

The objective was to increase the energy storage and power capacity of the existing Coo Pumped Storage Plant by 7.5%, while also extending the plant’s operational lifetime by an additional 40 years. This required a technically complex upgrade of critical infrastructure without compromising ongoing operations.

The Solution

Tractebel conducted a comprehensive feasibility study, including Finite Element Analysis (FEA) and fatigue calculations of key components. We prepared tender documents for construction and equipment procurement/erection, evaluated bids, and supported contract negotiations. As Owner’s Engineer, we provided end-to-end services throughout the design, manufacturing, construction, and commissioning phases—covering detailed design reviews, factory inspections, construction supervision, and technical and contractual assistance.

The Impact

The upgrade resulted in a 7.5% increase in energy storage capacity (+450 MWh / 600,000 m³) and power output (+3 x 26.5 MW → 79 MW). This enhancement enabled the plant to qualify for an 80% grid cost exemption over five years, reinforcing its role in grid stability and energy transition.