Canals, Tunnels and Penstocks

Exploratory work begins at site of 1.5 GW Coire Glas pumped storage

Exploratory work begins at site of 1.5 GW Coire Glas pumped storage
(Coire Glas pumped storage project)

Exploratory work at the site of the Coire Glas pumped storage project, which would be the UK’s first large-scale pumped storage scheme to be developed in 30 years, has commenced at Loch Lochy in the Great Glen in the Scottish Highlands.

The 1.5 GW Coire Glas project was initially approved for 600 MW scheme in December 2013, and revised plans were submitted in April 2018 to the Scottish Government for an up-to-1.5 GW scheme. The changes were designed to maximize the potential of the site and help the UK in its transition to a net zero energy system by 2050.

SSE Renewables selected Strabag UK, a mining and tunnelling contractor, to undertake the work earlier this year. The company was named the preferred tenderer to carry out the work after a rigorous selection process that concluded in April, according to a release.

The work will see the creation of a tunnel about 4 m wide and up to 1 km long, which will cut into the hillside toward the proposed location of the underground powerhouse complex. Samples of the materials within the hill will be analyzed, and survey and assessment work will be carried out to give a detailed understanding of the geological conditions. The information will then be used in detailed design of underground structures.

The findings of the exploratory works will be used to inform the final design of the project and will be an important consideration in SSE Renewables’ final decision on whether to proceed with the Coire Glas project.

“Coire Glas is one of the most significant engineering projects to take place in the UK for decades. The commencement of these exploratory works is a great milestone for everyone on the Coire Glas Project Team and at SSE Renewables,” said Ian Innes, project director for Coire Glas. “I am confident that Strabag UK’s experience will prove an asset as we undertake this critical phase in the development of the Coire Glas project.”

In November 2021, SSE Renewables’ parent company, SSE PLC, unveiled its Net Zero Acceleration Programme (NZAP), which commits to investing in critical low-carbon infrastructure needed in the net zero transition. Major infrastructure projects including Coire Glas are at the heart of the NZAP, with a target to double installed capacity by 2026 and more than treble it by 2031, increasing output fivefold to over 50 TWh annually.