ENGIE and La Caisse Select GE Vernova for the next phase of the modernization of Dinorwig pumped storage hydropower plant in North Wales, UK

Paris, France (July 28, 2026) - First Hydro Company (joint venture between ENGIE and La Caisse), and GE Vernova Inc. (NYSE: GEV), announce the next phase of the modernization/replanting of the Dinorwig pumped storage hydropower plant in North Wales, UK. Under the agreement, GE Vernova is expected to replace two pumped storage units as part of First Hydro's long-term replanting programme at Dinorwig, to help extend the life of the plant for decades to come, while enhancing the plant's reliability, availability and performance in support of UK grid stability.

Now over 40 years old, Dinorwig is one of Europe's largest pumped storage hydropower plants and is renowned for its rapid response capability, delivering up to 1,320 MW of power within 12 seconds from standby, and up to 1,800 MW in under a minute. With such characteristics, this plant plays a vital role in grid resilience and frequency response, providing a capacity equivalent to power around one million homes in the UK.*

As majority owner and operator of the plant through First Hydro Company, ENGIE is making a significant long-term investment to extend its operational life. The wider programme includes the replacement of key plant components across all six generating units, alongside significant infrastructure upgrades.

The modernization forms part of one of the UK's largest hydro refurbishment and replanting programme, helping to strengthen long-term grid resilience and support the integration of renewable energy in the UK's evolving electricity system. This programme is expected to extend the plant's life by at least 25 years, to ensure continued delivery of fast, flexible low-carbon power.

"This contract marks an important milestone in our long-term investment programme at Dinorwig," said Delphine Cherel-Sparham, Managing Director of ENGIE Hydro UK. "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. Together with GE Vernova, we are investing in the modernization of key generating units to help secure the plant's performance for decades to come."

"This project is a strong example of how GE Vernova can bring innovation and engineering expertise to a landmark hydro asset," said Emmanuel Mercier, GE Vernova's Hydro Power EMEA Leader. "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."

The announcement follows the successful completion of the pumped storage unit model test validation at GE Vernova's testing laboratory in Grenoble, France. As part of its scope, GE Vernova is expected to supply the upgraded motor generators and pump turbines, alongside refurbishment of embedded parts such as the spiral case, stay ring and draft tube. The project also includes an upgraded control system for the station, as well as low-voltage, medium-voltage and DC power supply systems. The pump turbines and motor generators were engineered respectively in GE Vernova's Centers of Excellence in Grenoble, France and Birr, Switzerland.

The project also builds upon GE Vernova's cross-business capabilities, including Variable Frequency Starting Equipment engineered, supplied and installed by GE Vernova's Power Conversion business in Germany, a protection system provided by Grid Solutions in Spain, and the manufacture of the generator shaft by Gas Power in Switzerland. The plant's control system will be refurbished using GE Vernova's industrial experience.

Pumped Storage Projects

Pumped storage hydro provides large-scale energy storage and fast-response flexibility, helping to balance electricity supply and demand while supporting the integration of renewable energy. Through First Hydro Company, ENGIE and La Caisse own and operate the Dinorwig and Ffestiniog pumped storage stations in North Wales, which together provide 2.1 GW of installed capacity and represent around 74% of the UK's pumped storage hydro capacity.

GE Vernova is one of the largest players in the global pumped storage space with nearly 30% of the global installed base and is currently developing more than 3 GW of pumped storage projects around the world.

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Note to editors:

Financial editors: the order was booked in Q2 2026.
* Assuming that the average UK household demand at a given moment: about 1.8 kW per home.

About ENGIE in the UK

ENGIE employs more than 8,000 people in the UK and operates right across the energy value chain, producing, storing, distributing, and supplying energy. It owns and manages a diverse portfolio of renewable generation and flexible storage assets, including Europe's largest pumped-storage hydro plant. It also supplies energy to more than 17,000 business customers and produces over 200 GWh of biomethane each year.

ENGIE owns UK Power Networks, the UK's leading electricity distribution network operator, serving 8.5 million customers across London, the South East and East of England. Through Ocean Winds, its joint venture, ENGIE is one of Scotland's largest offshore wind generators with 1.8 GW of capacity. Over more than 20 years, ENGIE has invested billions in the UK's energy transition - supporting energy security and enabling customers to decarbonise at scale.

ENGIE Press contact:

Alanna Rooney
Tel. UK: +44 7739072404
Email : [email protected] / [email protected]

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