ScottishPower, in a press release today said it has completed a two-year feasibility study to determine whether it is possible to expand 440-MW Cruachan pumped-storage hydro plant near Oban, Scotland, by 400 to 600 MW.
The company would invest between US$418 million to $557 million to complete the projected eight- to 10-year endeavor if the UK government approves all aspects of the expansion process.
Commissioned originally in 1965, the powerhouse is located 1 km inside Ben Cruachan Mountain. The scheme takes water between Cruachan Reservoir to Loch Awe and has a head distance of 396 m (1,299 ft).
Currently, according to ScottishPower, Cruachan can produce electricity for the national grid in 2 minutes, or 30 seconds if its turbines are already primed. It is also one of only four pumped-storage facilities in the UK.
The other three UK hydroelectric pumped-storage facilities include:
- 1.73-GW Dinorwig Power Station near Dinorwig, Llanberis in Snowdonia National Park in Gwynedd, North Wales;
- 360-MW Ffestiniog Power Station near Ffestiniog, in Gwynedd, northwest Wales; and
- 300-MW Foyers pumped-storage facility located on the southeast shore of Loch Ness, 30 km south of Inverness, Scotland.
The study shows that a new cavern would need to be excavated within Ben Cruachan Mountain, and the possibility that new dams could be constructed to increase the capacity of the upper reservoir.
ScottishPower is now considering all the options, but any project to expand Cruachan would include:
- Up to three years to secure Section 36 planning consent and other necessary consents;
- Six to seven years for construction and commissioning; and
- New cavern construction required and [plans] for a potential new dam.
In its release, Hugh Finlay, generation director at ScottishPower, said, “A new generation of pumped storage hydro would be a major asset for electricity systems worldwide as more renewable electricity continues to come on line. As well as being able to further support peak demand, expanded pumped storage would also be able to effectively store greater levels of electricity at times when renewable energy output is high but demand is low.
“Pumped storage hydro is the most cost effective and well-developed large-scale electricity storage technology in existence. We will now take forward our Cruachan findings with government and regulators.”
ScottishPower will now consider the next steps for the project, including discussions with the UK government on potential support mechanisms.