Britain’s largest natural battery project has reached a significant milestone, with SSE completing a £100 million exploratory works program at its Coire Glas site in the Scottish Highlands. This initiative marks the first major pumped storage hydro scheme in the UK in over 40 years.
The milestone saw SSE drill and blast a 1.2 km tunnel into the hillside, gathering crucial geological data for the project’s design. Over 90,000 tonnes of rock and earth were excavated during this phase, laying the groundwork for what could be a transformative asset in the UK’s renewable energy infrastructure.
Robert Bryce, Director of Hydro at SSE Renewables, emphasized the importance of recent government measures supporting long-duration electricity storage. “The decision earlier this year to introduce a cap and floor investment framework was a massive step forward in delivering more of the flexible homegrown energy the UK needs to enable clean power by 2030 and our transition to net zero by 2050,” Bryce stated.
Coire Glas, with a projected 1.3GW output and up to 30GWh of storage capacity, could supply electricity to three million homes for 24 hours. This capacity would nearly double Great Britain’s current electricity storage, allowing more effective use of renewable energy.
The UK Government is planning to introduce a cap and floor framework to foster investment in such projects, while the National Energy System Operator (NESO) identified pumped storage hydro as critical for achieving clean power goals by 2030. “We are encouraged to see that NESO has identified pumped storage as critical to both its potential pathways to achieve clean power by 2030,” Bryce added. “We eagerly await the UK Government’s response to the CP30 Report, which is expected to set out the practical steps Government will now take to make that pathway a reality.”
Scotland’s geography provides an ideal environment for pumped storage, storing surplus low-carbon power for times when renewable generation dips. Coire Glas can ramp up to full generating capacity in under 60 seconds and begin generating in just 10 seconds, enhancing grid stability.
The predominantly civil engineering project is expected to boost the UK economy and local supply chains, with significant domestic spending. If the cap and floor framework progresses swiftly, SSE anticipates Coire Glas could contribute to the energy grid by the early 2030s.
Additionally, the project has supported over £160,000 in community and educational initiatives and provided around 30% local employment. Future developments could unlock a multi-million-pound community benefit fund for the region.
