SSE allocates £100 million to Britain’s ‘biggest pumped hydro scheme in 40 years’. Image: SSE.

UK power generator SSE has confirmed it will allocate £100 million in capital to boost Coire Glas – a Scottish-based pumped hydro storage project with the potential to be the “biggest” in 40 years.

Situated near Loch Lochy, between Fort William and Inverness, the Coire Glas project could more than double Britain’s total current electricity storage capacity and could require a capital investment of over £1.5 billion to construct.

The project, which subject to positive development progress and prevailing policy environment could be constructed in 2031, would be capable of delivering 30GWh of long duration storage.

Excess energy would be taken from the grid and to pump water 500 metres up a hill from the Loch to a upper reservoir similar in size to around 11,000 Olympic-sized swimming pools. When required, this water would then be released to power the grid when intermittent energy generation capacity, such as solar and wind, is low and demand is high.

SSE hopes to make a final investment decision on Coire Glas in 2024 with the £100 million investment going towards the pre-construction refinement phase of the project.

“Coire Glas will be one of the most ambitious energy infrastructure projects the UK has ever seen and is a key component of SSE’s commitment to helping lead Scotland and the UKs’ energy transition,” said Gregor Alexander, finance director at SSE.

“The £100 million investment we have announced today will help play a crucial role in further advancing the Coire Glas project towards a final investment decision in 2024, which will enable the project to move towards construction. If delivered around the turn of the decade, Coire Glas could play a crucial role in getting the UK to net zero.

“Whilst Coire 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”

The next phase of the project includes a detailed design and refinement, with construction planning and procurement set to progress throughout 2023 and into 2024.

Last year, the UK government outlined within the British Energy Security Strategy that it would ensure a more flexible, efficient system for both electricity generators and users.

One of the key steps in achieving this is ensuring there is sufficient large-scale long-duration electricity storage to balance the overall system. This can be supported by developing appropriate policy to enable investment, the strategy stated.

Coire Glas could well be supported by the government’s plans with SSE stating the support could include the introduction of a revenue stabilisation mechanism in the form of an adapted cap and floor scheme. This would support investment in long-duration storage.

“The Scottish government has long been supportive of pumped hydro storage capacity, which we believe will play a key role in the energy transition and is a vital component of a more flexible, resilient and secure electricity supply,” said Michael Matheson, net zero and energy secretary for the Scottish government.

“However, 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.”