Seismic surveys underway at site of new Ben Cruachan 600MW pumped hydro scheme

Seismic surveys are underway on the slopes of Ben Cruachan in Scotland where Drax is planning to construct a new 600MW pumped hydro-electricity storage scheme.The Cruachan 2 project will be adjacent to the energy company’s existing Cruachan facility. It received planning consent from the Scottish government last summer and in the autumn Cowi and Studio Pietrangeli signed on to provide consultancy services .Drax says the project will cost £500M and it will be online in 2030.The seismic surveys are being undertaken to provide geological data about the rock in which the new plant will be housed. The process involves drilling holes in the rock and laying small explosive devices. These are then detonated to produce a powerful sound wave that penetrates the rock mass.It is expected that the sound waves will penetrate up to 60m below the surface before its reflected signal fades away. Geophones mounted on the ground measure the progress of the sound waves and collect information about fractures, fissures or potential weak spots in the rock.Pumped hydro storage plants act like batteries, using reversible turbines to pump water from a lower reservoir to an upper reservoir which stores excess power from lower carbon energy sources when supply outstrips demand. The same turbines are then reversed to bring the stored water back through to the plant to generate power when it is needed.The existing Cruachan power station was built in the 1960s and is one of only four active pumped storage facilities in the UK. Building the new station adjacent to it offers an opportunity to develop large scale energy storage capacity while maximising the existing assets in the Cruachan Reservoir and access roads and minimising the disturbance in the surrounding environment, according to Drax.Drax development manager Steve Marshall believes that Cruachan 2 “will be one of the most significant engineering projects in Scotland for many decades”.“The start of these seismic surveys of the mountain is a real milestone moment for the project and everyone at Drax is excited to see the development take another step forward, These surveys will further complement borehole drilling works undertaken in 2022 and 2023 at the site,” he added.“With the project granted development consent from the Scottish Government, we hope the next UK Government will continue policy development in this area at pace to enable a new generation of pumped storage plants to come online as soon as possible.”Other pumped storage projects in ScotlandIn December 2023, Norwegian hydropower electricity producer Statkraft – which describes itself as Europe’s largest renewable power generator – announced it would acquire the Red John Pumped Storage Hydro Scheme from Scottish clean energy development company Intelligent Land Investments Group (ILI).The Red John scheme has since been renamed to Loch na Cathrach.ILI took the 450MW Pumped Storage Hydro project from initial conception to being development ready after was first conceived in 2015. The scheme was granted consent by Scottish Government ministers in June 2021, and which point it was costed at £550M.Aecom was tasked with providing environmental impact assessment and surveying, consenting and engineering support from the scheme’s feasibility stage to through to ministerial greenlighting.SSE’s Foyers Power Station also abstracts water from Loch Ness and uses it to drive two 150MW turbines.According to SSE, Foyers was intended to make use of surplus electricity produced by the Hunterston B nuclear power station in North Ayrshire which began operating in 1976.The biggest pumped hydro-electric project currently consented is SSE Renewables’ £1.5bn and 1.5GW Coire Glas at Loch Lochy in the Great Glen in the Scottish Highlands, on which Cowi is also working. Last year spoke to Cowi and SSE to find out more about the challenges of the project .Additionally, last month Glen Earrach Energy announced plans to build a 2GW pumped hydro facility at the Balmacaan Estate in Scotland, next to Loch Ness at a cost of £2-3bn.Like what you’ve read?