plans would see the existing Sloy Power Station on the banks of Loch Lomond converted into a pumped storage hydro scheme with a pumping capacity of up to 100MW.
The proposed project involves installing new pumps at the Inveruglas site to move water from Loch Lomond to Loch Sloy during periods of low electricity demand. This stored water would then be released to generate power when demand peaks. Additionally, the plan includes upgrading the station’s 32.5MW G4 turbine, increasing the total generating capacity from 152.5MW to 160MW. If approved, SSE aims to finalize investment decisions by late 2027, with the conversion completed and operational by the end of 2030.
The initiative is expected to support up to 70 full-time equivalent jobs during development, contributing to the local economy around Loch Lomond. SSE also plans to establish a community benefit fund, complementing its recently launched £10 million Hydro Community Fund. Robert Bryce, Director of Hydro at SSE Renewables, emphasized the project’s significance: “The proposed pumped storage hydro scheme will play an important role in the UK Government’s Clean Power by 2030 ambitions, providing firm, flexible renewable energy for up to 100 hours non-stop at the flick of a switch. The existing Sloy Power Station has been operational since 1950 and over the past seven decades has played a significant role in our energy system. The new proposals will ensure this remains an important asset for decades to come.”
Bryce further noted: “If consented, the scheme will provide an economic and employment boost to the local area and help provide balance to our increasingly renewables-led grid, during times of peak demand. This latest proposal, alongside our other investments in the technology, are a further example of the importance of hydro as a key part of a homegrown UK energy system.”
Currently, Sloy Power Station is the UK’s largest conventional hydroelectric facility, generating around 130 million kilowatt hours annually under typical rainfall conditions. Water from Loch Sloy flows through a tunnel and steel pipelines to drive four Francis turbines. To address environmental considerations, SSE Renewables has prepared a detailed report covering ecology, water, noise, heritage, and transport, which is accessible on their website.
This project aligns with efforts to enhance renewable energy infrastructure, ensuring a stable and sustainable energy supply while supporting local communities and environmental stewardship.
