Inside Dinorwig’s Pumped Storage Hydro Station
Ever wondered how we store energy at scale to build a flexible, renewables-powered grid… using water?
In the first episode of our new ENGIE X Engineering series, we go deep inside Dinorwig – one of the UK’s most iconic pumped storage facilities.
Follow the team as they reveal how gravity, water, and world-class engineering deliver fast, responsive power, right when the grid needs it most.
Police Escort Required: Delivering 4 Giant Valves to Dinorwig
Some of the biggest valves in the world are making their way to Dinorwig – each one weighing in at a staggering 160 tonnes.
In Episode 2 of our ENGIE X Engineering series, follow the journey as these colossal valves are transported to site, complete with road closures and a police escort.
The four new valves will replace the originals from the 1980s, marking the beginning of a major replanting programme led by our expert engineers at one of the UK’s most iconic pumped storage sites.
Installing the World’s Largest Valves – with Only Millimetres to Spare
The giant valves have arrived on site, now comes the real challenge.
In this latest episode of our ENGIE X Engineering series, witness the high-stakes installation of 160-tonne valves at Dinorwig, where there’s no room for error… literally.
This is the kind of work you rarely see, but it’s right at the heart of building a more flexible, resilient grid.
Powering Wales’ Future: A Visit from the First Minister Eluned Morgan
In this episode of ENGIE X Engineering, go behind the scenes of the First Minister’s visit.
From the turbine hall to the control room, watch as she meets the engineers powering the future of clean, flexible energy in the UK.
Draining Dinorwig: Exploring the Massive Tunnels
Europe’s largest pumped storage facility, Dinorwig, is drained down – giving the team a once-in-a-lifetime chance to access the giant tunnels buried inside the mountain.
In the next episode of ENGIE X Engineering, let’s explore the tunnels that normally carry an Olympic swimming pool’s worth of water every few seconds!
Watch to discover what it takes to work in these vast underground spaces, and meet the team making it possible.
Replacing the 40-Year-Old Switchgear in Europe’s Largest Natural Battery
Rushing water and spinning turbines is only half the story. The next challenge? Getting that energy out to the grid!
Watch as we head into the switchgear galleries in the next episode of ENGIE X Engineering, where 40-year-old infrastructure is being replaced with state-of-the-art technology.
Painting Dinorwig’s upper reservoir
It’s not every day you see the dam walls up close! Explore one of the most restricted parts of Dinorwig in the penultimate episode…
With the station fully drained, a specialist team takes on the high-risk job of painting the upper reservoir walls, normally holding 10 million tonnes of water.
Watch precision engineering in action as they protect and extend the life of this critical infrastructure.
The people behind the power
It all comes back to the people.
In the final episode of ENGIE X Engineering, we hear from the team behind Dinorwig – many of whom have been part of this iconic site and community for decades.
Their pride, experience, and dedication are the heart of this £1 billion replanting journey, a story that’s about more than extreme engineering.
It’s about the people behind the power.
From First Hydro
Replanting First Hydro
ENGIE and partner CDPQ are investing up to £1 billion in a major 10-year refurbishment of First Hydro Company’s two pumped storage assets in Dinorwig and Ffestiniog, North Wales.
