In a major boost for the UK’s renewable energy infrastructure, First Hydro Company—a 75:25 joint venture between ENGIE and La Caisse—has selected GE Vernova to modernize the first two generating units at the iconic Dinorwig pumped storage hydropower plant in North Wales. This strategic contract marks a critical milestone in a long-term replanting program designed to extend the facility’s operational life by at least 25 years, ensuring it remains a cornerstone of UK grid stability for decades to come.
The Powerhouse of Dinorwig
Commissioned in the early 1980s, Dinorwig is Europe’s largest pumped storage hydropower plant and a true marvel of engineering. Housed within the largest man-made cavern in Europe, the plant is renowned for its blistering rapid-response capability. It can deliver up to 1,320 MW of power within just 12 seconds from standby, and ramp up to 1,800 MW in under a minute. This immense flexibility provides a capacity equivalent to powering roughly one million UK homes, making it an indispensable asset for grid resilience and frequency response.
What’s Being Upgraded?
The modernization project targets two of the plant’s six 315-MW generating units. GE Vernova’s comprehensive scope of work includes:
- New Core Components: Supply of upgraded motor generators and pump turbines, engineered at GE Vernova’s Centers of Excellence in Grenoble, France, and Birr, Switzerland, following rigorous model test validation.
- Embedded Refurbishment: Overhaul of critical embedded parts, including the spiral case, stay ring, and draft tube.
- Advanced Control Systems: Installation of a state-of-the-art station control system, alongside new low-voltage, medium-voltage, and DC power supply systems.
- Cross-Border Expertise: The project leverages GE Vernova’s global network, featuring Variable Frequency Starting Equipment from Germany, a protection system from Spain, and generator shaft manufacturing from Switzerland.
Securing the UK’s Energy Future
As the UK’s electricity system evolves to accommodate higher penetration of intermittent renewable energy, the need for long-duration, flexible energy storage has never been more critical. Pumped storage remains the undisputed workhorse of grid-scale energy storage, and upgrading aging 1970s and 1980s fleets is now a top priority for operators worldwide.
Delphine Cherel-Sparham, Managing Director of ENGIE Hydro UK, highlighted the strategic importance of the investment: “This contract marks an important milestone in our long-term investment programme at Dinorwig. As majority owner and operator of the plant, ENGIE is committed to ensuring Dinorwig continues to provide the flexibility, resilience, and energy storage capabilities that the UK electricity system increasingly depends upon.”
Emmanuel Mercier, GE Vernova’s Hydro Power EMEA Leader, echoed this sentiment: “This project is a strong example of how GE Vernova can bring innovation and engineering expertise to a landmark hydro asset. Dinorwig is a highly strategic facility for the UK power system, and we are proud to support First Hydro Company in strengthening the reliability and performance of this important plant.”
Looking Ahead
With First Hydro Company already operating 2.1 GW of installed capacity across Dinorwig and the Ffestiniog stations (representing roughly 74% of the UK’s total pumped storage capacity), this modernization is a vital step in safeguarding the nation’s energy security. By breathing new life into this 40-year-old giant, GE Vernova and ENGIE are ensuring that Dinorwig will continue to deliver fast, flexible, and low-carbon power well into the future, supporting the UK’s ambitious net-zero goals.