Renewable energy company Drax Group is kickstarting the planning process to build a new underground pumped storage hydro power station – more than doubling the electricity generating capacity at its Cruachan facility in Scotland.
The project plan was announced as the UK prepares to host the COP26 climate conference in Glasgow. The proposed expansion of the hydro power station 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.
Pumped storage hydro is a critical technology which enables more renewable power and supports Scotland’s electricity system, helping the country move towards its target of reaching net zero by 2045, five years before the rest of the UK.
Will Gardiner, Drax Group chief executive officer, said:
“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 decarbonise. 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.
Last year, the UK’s lack of energy storage capacity meant wind farms had to be paid to turn off and we lost out on enough renewable power to supply a million homes. We need to stop renewable power from going to waste by storing it, and Drax is ready to move mountains to do just that.”
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. Work on the new pumped storage hydro power station could begin as soon as 2024.
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.