Our Coire Glas project in the Scottish Highlands could be the first major pumped storage hydro scheme built in more than 40 years. This is significant for the 2030 Clean Power plan. The National Energy System Operator (NESO) has said pumped storage hydro will be critical for energy flexibility as part of the plan.
Coire Glas is effectively Britain’s largest natural battery. It could power three million homes for up to 24 hours. And would nearly double Great Britain’s total current electricity storage capacity.
Find out more about how pumped storage hydro works.
Long-duration electricity storage project cap and floor
The UK Government confirmed earlier this year a cap and floor investment framework would be introduced to enable the deployment of long-duration electricity storage projects.
Robert Bryce, Director of Hydro at SSE Renewables: “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.
“We are encouraged to see that NESO has identified pumped storage as critical to both its potential pathways to achieve clean power by 2030. 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. In our view this will require accelerated implementation of the cap and floor with a view to enabling final investment decisions at pace on the most advanced and impactful projects.”
Coire Glas pumped storage hydro update
The project has reached a significant milestone in December 2024. We have completed a £100m exploratory works programme. A 1.2km tunnel has been drilled and blasted into the hillside in the Scottish Highlands.
“Having reached this important milestone in the exploratory works, we are now looking forward to seeing further detail on how the first projects will be taken forward under the scheme, which will be a key enabler of the Government’s Clean Power Plan.” Robert Bryce, Director of Hydro at SSE Renewables
The exploratory works gathered important geological data to inform the main design of the scheme. Over 90,000 tonnes of rock and earth were excavated.
About Coire Glas
Coire Glas received planning consent in 2020. The project is the largest and most advanced of the more than 10GW of long-duration electricity storage projects in the pipeline in the UK. It could have up to 30GWh of storage capacity to power three million homes for up to 24 hours. Coire Glas would be able to ramp to its full generating capacity in under 60 seconds to rapidly support grid stability and start generating in under 10 seconds.
Scotland’s geography provides the ideal environment for pumped storage hydro assets. Pumped storage hydro is critical to delivering a flexible clean energy system. It can store low-carbon power in times of surplus, to be deployed when the wind doesn’t blow and the sun doesn’t shine.
With an appropriately designed cap and floor regime in place, and swift action to progress the first projects, Coire Glas could be delivering flexibility to the energy system in the early 2030s.
The Coire Glas project has also supported more than £160k of community and educational initiatives. The project has provided almost c.30% local employment. If it goes ahead a multi-million-pound community benefit fund would be open to the region.
Find out more about how pumped hydro storage can help us achieve our net-zero targets.