Milestone moment in bid to expand 'Hollow Mountain' Cruachan hydro power station

Plans to expand the “Hollow Mountain” Cruachan Power Station in Argyll – a move expected to create hundreds of jobs and see its power-generation capacity hit the accelerator – are taking a key step forward.

Renewable energy firm Drax has announced that it will today officially apply for planning permission to build a new underground pumped storage hydro power station at the site, claiming this could be the first newly constructed plant of its kind in the UK in more than 40 years.

The business said this would more than double the electricity-generating capacity of the facility deep inside Ben Cruachan – Argyll's highest mountain – to 1.04 gigawatts, via the new plant in a specially hollowed-out cavern that would be large enough to fit Big Ben on its side.

Drax believes it could be operational as soon as 2030, with construction work getting under way in 2024, and the latest development carries forward plans the firm has previously highlighted, last year deeming the proposed expansion an “exciting and important” project.

Drax believes the expansion will provide “critical” storage capacity to strengthen the UK’s energy security and speed up the journey to net zero, and would require the excavation of around two million tonnes of rock to create the cavern, tunnels and other parts of the new power station.

It has forecast that the “major” infrastructure project will support 900 jobs over the six years of construction required across the supply chain in a range of industries from quarrying and engineering to transport and hospitality, with around 150 on-site local building jobs to be created during the development.

The aim for the new power station is to use reversible turbines to pump water from Loch Awe to the upper reservoir on the mountainside to store excess power from wind farms and other low-carbon technologies when supply outstrips demand and then use this stored water to generate renewable power when required.

Renewable power firm Drax says the proposed expansion would create the first newly constructed plant of its kind in the UK in more than 40 years. Picture: contributed.

Ian Kinnaird, Drax's Scottish assets director, said: "Drax's plan to expand Cruachan will strengthen the UK's energy security by enabling more homegrown renewable electricity to come online to power homes and businesses across the country, helping to end our reliance on imports and cut costs.

Moving mountains

"This major infrastructure project will support hundreds of jobs and provide a real boost to the Scottish economy. Only by investing in long-duration storage technologies can the UK reach its full renewable potential, and Drax is ready to move mountains to do just that."

Claire Mack, chief executive of industry body Scottish Renewables, said: "Pumped storage hydro is a critical technology needed to meet net zero. Over the last decade we have managed to develop the technologies to decarbonise the power system such as wind and solar – but what we really need now is greater flexibility to fully optimise those technologies.

"That's why the success of long-duration storage projects such as Cruachan 2 is absolutely vital to Scotland and the whole of the UK."

Drax’s plans to expand Cruachan have also won support from former Australian prime minister and hydropower advocate Malcolm Turnbull – who says they “will enable the UK to enhance its energy security and enable more renewable power to come online”.

Research published last year found that Drax generates more than £200 million for the Scottish economy and supports 1,200 jobs.