SSE Renewables unveiled ambitious plans on Monday (22 May) to transform what it hails as Britain’s largest conventional hydro power plant into a pumped hydro storage facility.
The energy provider disclosed its intentions to convert the 152.5MW Sloy hydroelectric power station, nestled on the banks of Loch Lomond in Argyll and Bute, central Scotland, into a pumped hydro energy storage (PHES) system.
Pending final project design, SSE projects that the revamped Sloy scheme could offer up to 25GWh of long-duration electricity storage capacity. This translates to the provision of flexible renewable energy for up to 160 continuous hours.
Finlay McCutcheon, SSE Renewables' Director of Onshore Europe, emphasized the significance of repurposing the Sloy facility, stating, “In converting our existing Sloy conventional hydro power plant to a pumped hydro storage facility, we can provide the additional large-scale, long-duration electricity storage we need as part of the country’s future energy mix.”
He added, “The development of pumping capability at Sloy also complements our development plans for our other pumped hydro storage project at Coire Glas. Taken together and if approved for delivery, Coire Glas and Sloy can treble Britain’s current flexible electricity storage capacity.”
The conversion process for the Sloy project will entail refining the project design to transition from conventional hydro power to pumped hydro storage technology. This will be followed by a period of public consultation later this year. SSE anticipates that a planning application could be submitted to the Scottish Government by late 2023 or early 2024, with a final investment decision expected by late 2025 and full commissioning targeted for 2028.
Scottish Government Cabinet Secretary for Net Zero, Energy and Transport, Humza Yousaf, emphasized the potential role of hydro power and long-duration energy storage technologies in the transition to net zero, urging the UK Government to provide appropriate market mechanisms to realize this potential fully.
SSE's venture into pumped hydro storage aligns with its broader commitment to renewable energy flexibility in Scotland. Earlier reports indicated the company's allocation of £100 million to bolster the Coire Glas pumped hydro storage project, poised to significantly enhance Britain’s electricity storage capacity. Located near Loch Lochy, the Coire Glas project has the potential to deliver 30GWh of long-duration energy storage, with an estimated construction investment exceeding £1.5 billion.