Drax Group is seeking planning permission to build a new 600-MW underground pumped hydro storage power station at its 440-MW Cruachan facility in Scotland, which would more than double the site’s electricity generating capacity.
The project, announced as the UK prepares to host the COP26 climate conference in Glasgow, 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 new power station will be located within a new, hollowed-out cavern inside Ben Cruachan, Argyll’s highest mountain, to the east of Drax’s existing 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 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.
“This is an exciting and important project which underlines Drax’s commitment to tackling the climate crisis and supporting the energy system as it continues to decarbonize,” said Will Gardiner, Drax Group chief executive officer. “Our plans to expand Cruachan will unlock more renewable electricity to power homes and businesses across the country, and support hundreds of new jobs in rural Scotland. We need to stop renewable power from going to waste by storing it, and Drax is ready to move mountains to do just that.”
To deploy this critical technology, Drax must secure consent under Section 36 of the Electricity Act 1989 from Scottish Ministers, a process that takes about one year to complete from the application’s submission. 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 be secured in new pumped storage hydro projects, with no new plants built anywhere in the UK since 1984 despite their critical role in decarbonization, according to a press release.
Drax Group’s purpose is to enable a zero-carbon, lower cost energy future and in 2019 announced an ambition to be carbon negative by 2030, using bioenergy with carbon capture and storage (BECCS) technology. Drax owns and operates a portfolio of renewable electricity generation assets in England and Scotland. The assets include the UK’s largest power station, based at Selby, North Yorkshire, which supplies 5% of the country’s electricity needs.