RENEWABLE ENERGY
In the northern reaches of Snowdonia, you’ ll find a mountain unlike any other in Wales. At first glance, Elidir Fawr is much like the other giants in the region, with its snowcapped peaks and expansive views towards the Irish Sea making it a popular climb among hikers. But, beneath the surface, all is not quite what it seems.
Under the slate and scree, built deep in the heart of the mountain, is the UK’ s largest battery: the Dinorwig Power Station. This huge pumped storage hydropower station has a capacity of 1.7GW and has earned Elidir Fawr the nickname‘ Electric Mountain’ since it was commissioned in 1984.
As just one of four pumped storage hydro plants in the country, Dinorwig has been a key part of Britain’ s grid stability over the years – a role that has only grown as more intermittent wind and solar generation has come onto the system.
Despite its age, Dinorwig is still one of the country’ s most ambitious and powerful energy projects. Nevertheless, it is currently undergoing a major renovation to bring it in line with new standards for hydroelectric plants.
Dinorwig’ s owner is First Hydro, a company owned 75 % by ENGIE and 25 % by La Caisse. The firm has selected American energy giant GE Vernova to carry out this modernisation programme, which will involve the replacement of two of the plant’ s 315MW generating units.
What the contract covers GE Vernova has been brought in to update the hardware at Electric Mountain. The firm has been contracted to change out Dinorwig’ s motor generators, pump turbines and control system. It is also due to refurbish some of the plant’ s other components including the spiral case, stay ring and draft tube.
Though GE Vernova is based in the US, its network of R & D and manufacturing hubs across Europe give projects like Dinorwig access to
118 October 2026