SSE Renewables announced on Tuesday its plans to invest $122.9m (£100m) into the Coire Glas hydro storage scheme in the Scottish Highlands, the UK’s largest hydro project in decades.
Once completed, the large-scale hydro scheme would more-than double the UK’s ability to store energy for long periods of time and would be capable of delivery 30GW of long-duration storage.
The scheme was first approved by the Scottish government in 2020 and is expected to require a total capital investment of $1.8bn (£1.5bn) to construct. It will be the UK’s largest hydro project since the “Electric Mountain” project was completed in Snowdonia in 1984.
Hydropower continues to be a key source of renewable energy globally. A report found that hydropower made the biggest contribution to the world’s energy mix of any renewable source in 2019 with a total contribution of 10,455TWh, leaving it behind only coal, oil, natural gas, and biomass in the world’s power mix.
Planning is expected to progress through 2023 and into 2024, with a final investment decision anticipated next year. Half of the $122.9m (£100m) boost will be allocated to the pre-construction refinement phase of the project.
Coire Glas sits on the shores of Loch Lochy. It will have a proposed 92m-tall dam and reservoirs located at different heights in the Great Glen, the geological fault that slices through the Highlands between Fort William and Inverness.
The scheme will take excess energy from the grid and use it to pump water 500 metres uphill from Loch Locky to an upper reservoir with a capacity equal to 11,000 Olympic-sized swimming pools, where it will be stored. When extra power is needed, water will be released downstream to produce hydropower, which can be fed back to the grid.
Waiting on the UK government
According to SSE, the power released from storage would be enough to power three million homes in under five minutes. It also predicts that at its peak, the project will create up to 500 full-time construction jobs.
However, SSE has also stated that it is awaiting confirmation from the UK government on how it intends to financially support the development of long-duration electricity storage. Suggestions for this include the introduction of a “revenue stabilisation mechanism” in the form of an adapted cap and floor scheme. This could come alongside broader considerations of how the electricity market values the contributions of low carbon flexible assets.
SSE finance director Gregor Alexander said in a statement: “Whilst Goire Glas doesn’t need subsidy, it does require more certainty around its revenues and it is critically important the UK Government urgently confirms its intention on exactly how they will help facilitate the deployment of such projects.”
SSE’s Finlay McCutcheon said via the BBC that there is a clear case for the UK government to support hydropower. The company’s existing assets has been “absolutely critical” in keeping up with electricity demand during a “full-blown energy crisis” in the UK and Europe, he said.
The $122.9m (£100m) investment comes on the 80th anniversary of the Scottish Hydro Electric Development Act 1943, which nationalised the industry and paved the way for construction of over 50 dams.
Scotland’s net zero and energy secretary Michael Matheson added: “It is critical that the UK Government puts in place the appropriate market and regulatory arrangements to support the industry’s development as a matter of urgency. Only with a supportive policy environment can this sector realise its full potential.”