Coire Glas power station is a proposed 1.3GW pumped storage hydroelectric power station in the

Scottish Highlands The Highlands (; , ) is a historical region of Scotland. Culturally, the Highlands and the Scottish Lowlands, Lowlands diverged from the Late Middle Ages into the modern period, when Scots language, Lowland Scots language replaced Scottish Gae ...

. If built, it will double the UK's ability to store energy for long periods.

Geography

Loch Lochy Loch Lochy () is a large freshwater loch in Lochaber, Highland (council area), Highland, Scotland. With a mean depth of , it is the third-deepest loch of Scotland. Geography Located southwest of Loch Ness along the Glen Albyn, Great Glen, the lo ...

lies along the

Great Glen The Great Glen ( ), also known as Glen Albyn (from the Gaelic "Glen of Scotland" ) or Glen More (from the Gaelic "Big/Great Glen"), is a glen in Scotland running for from Inverness on the edge of the Moray Firth, in an approximately straig ...

of Scotland, at an altitude of 29m above ordnance datum (AOD). Above its north-western shore, the

Munro A Munro (; ) is defined as a mountain in Scotland with a height over , and which is on the Scottish Mountaineering Club (SMC) official list of Munros; there is no explicit topographical prominence requirement. The best known Munro is Ben Nevi ...

mountain

Sròn a' Choire Ghairbh Sròn a’ Choire Ghairbh is a Scottish mountain situated on the northern side of Loch Lochy, 13 kilometres north of Spean Bridge in the Highland Council area. Overview Sròn a’ Choire Ghairbh reaches a height of 937 metres (3074 feet) ...

reaches a height of 937m. The north-east slope of the summit forms the headwall of the Coire Glas, a horseshoe-shaped glacial corrie. The corrie tarn, ''Loch a’ Choire Ghlais'', lies at an altitude over 500m AOD.

Proposal

Damming the mouth of the Coire Glas valley will create the upper reservoir. The crest of the dam will be around 700m long and 92m above ground level at its tallest point. When full, the reservoir will be approximately 1km long and 500m across, with a maximum surface area of 0.63km². The water level will vary between 494m and 558m AOD. The storable volume of 25.9 million m³, corresponds to a variation of 1.5m in the level of the 1720ha Loch Lochy. A sloping headrace tunnel will take water down from the upper reservoir through the mountain to a vertical high-pressure shaft leading down to turbines located in a cavern within the mountain itself, and thence to an upwards sloping tailrace discharging into Loch Lochy. The turbines, motor-generator sets and water channels are reversible, so that water from the loch can be pumped back uphill to store electrical energy when needed. As of May 2023, the power station is planned to have four 324MW turbines with a total generating capacity of 1300MW. When full, the system would store 30GWh of energy, enough for 24 hours of non-stop generation at full output. The power station would be able to switch from standby to stable generation within 30 seconds.

Current status

In August 2024, the roughly 5 metre wide and 1.2 km long exploratory tunnel was completed, yielding geological insights for the main construction. A final investment decision will depend on UK government assurances about how the regulated electricity market would reward storage schemes. SSE hope to make that £1.5Bn decision in 2024, in which case the scheme could be completed in 2031.

Project history

A 600MW scheme was first approved in 2013. The Scottish Government approved the scheme in 2020. In March 2023, SSE announced plans to spend £100M in exploratory work, including drilling a tunnel 1km into the mountainside to assess the geology.

References

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External links

Project website

Description of proposed development, from planning application documentation

Stakeholder briefing (May 2023)
Pumped-storage hydroelectric power stations in the United Kingdom Hydroelectric power stations in Scotland