Investing in future flexibility and clean power

ENGIE’s £1 billion investment programme is already underway and will keep Dinorwig and Ffestiniog in operation for at least another 25 years. These flexible generation assets, based in North Wales, are reaching end of life and the investment will ensure clean energy can continue to flow into the next few decades, helping the UK achieve Clean Power by 2030. 

The re-planting at Ffestiniog will be completed by July 2026, following a 9-year refurbishment, whilst at Dinorwig, work has only just begun. Due to the scale and complexity of the project, it will take up to 10 years to complete and a final investment decision on how many units to replant at Dinorwig is yet to be made.

Replanting involves replacing generating units and main inlet valves, some of the largest in the world, which control the flow of millions of litres of water. To carry out the work, the plants must be “drained down” – where water is stored in the lower reservoirs only. The water pressure in the shafts is higher than a nuclear submarine can withstand and so the drain down happens slowly and carefully, over the course of several weeks. Once empty of water, engineers climb inside the water shafts, carrying out thorough safety and integrity inspections.

Dinorwig, with its 1.8 GW capacity and Ffestiniog, with 0.3 GW, help keep the national electricity system balanced, offering instant system flexibility at short notice. The plants offer the flexibility needed to manage the day-night patterns of electricity consumption and support the integration of intermittent renewables onto the system.

Secretary of State for Energy Security and Net Zero, Ed Miliband said: “Companies like ENGIE understand that clean energy is the economic opportunity of the 21stcentury, and are investing in the technologies the UK needs to support lower energy bills, protect our energy security, and create good local jobs.”  

First Minister of Wales, Eluned Morgan said: “Investments such as these create high quality jobs for the local community. ENGIE is a longstanding investor in Wales, employing around 200 permanent staff and I’m pleased to support its replanting scheme, which will see the facilities continue to operate for another 25 years.”   

Assets on this scale are incredibly difficult to build today, so we believe it is essential to preserve and cherish the existing clean power assets we have in the UK if we are to achieve the energy transition.