SSE Renewables has finished a critical phase in the Coire Glas pumped storage project in the Scottish Highlands, completing a 1.2km exploratory tunnel. This marks a major step forward in the UK’s first significant pumped storage scheme since 1984, located at Loch Lochy, designed to provide 30 GWh of electricity storage—enough to power three million homes for 24 hours.
The tunnel, built by STRABAG UK, will provide essential geological data for the project’s final design. SSE Renewables targets a final investment decision by late 2025 or early 2026, with construction potentially beginning in late 2026, pending a favourable cap and floor mechanism.
The next steps involve further drilling and testing to finalize the design of the underground powerhouse.