Drax unveils plan to expand ‘Hollow Mountain’ Cruachan power station

Renewable energy company Drax Group is kickstarting the planning process to build a new underground pumped hydro storage power station – more than doubling the electricity generating capacity at its iconic Cruachan facility in Scotland.The project will support almost 900 jobs in rural areas across Scotland during construction and will provide critical storage capacity needed to support a net zero power system.The 600MW power station will be located inside Ben Cruachan – Argyll’s highest mountain – and increase the site’s total capacity to 1.04GW. The new power station would be built within a new, hollowed-out cavern which would be large enough to fit Big Ben on its side, to the east of Drax’s existing 440MW pumped storage hydro station. More than a million tonnes of rock would be excavated to create the cavern and other parts of the power station. The existing upper reservoir, which can hold 2.4 billion gallons of water, has the capacity to serve both power stations.Like Drax’s existing site, the new station will be able to provide lifeline stability services to the power system alongside acting like a giant water battery. By using reversible turbines to pump water from Loch Awe to the upper reservoir on the mountainside, the station can store power from wind farms when supply outstrips demand. The stored water would then be released back through the turbines to generate power quickly and reliably when demand increases. This will help to cut energy costs by reducing the need for wind farms to be paid to turn off when they are generating excess power. The new station would have the capacity to generate enough power for around a million homes.Drax’s decision to pursue planning approval has been welcomed by the Hollow Mountain’s local MP and MSP.In order to deploy this critical technology, Drax must secure consent under Section 36 of the Electricity Act 1989 from Scottish Ministers – a process which takes around one year to complete from the application’s submission.Alongside a successful Section 36 application, the project will also require an updated policy and market support mechanism from the UK Government. The existing lack of a framework for large-scale, long-duration storage and flexibility technologies means that private investment cannot currently be secured in new pumped storage hydro projects, with no new plants built anywhere in the UK since 1984 despite their critical role in decarbonisation.The first phase of the Section 36 application process includes public consultation this summer, when people can provide comments on Drax’s proposals for Cruachan via the project website from 1 July. Further consultation events are planned for later in the year, and an application is then expected to be submitted to Scottish Ministers in early 2022.