Cruachan Pumped Storage Scheme

Located on Loch Awe.
1964 Construction completed by North of Scotland Hydro-Electric Board
Initially 2 of the turbines were in use; within 2 years the other 2 were commissioned taking electrical capacity to 440MW; storage capacity is 10.0 GWh
2018 Acquired by Drax Group plc.
There are now plans to upgrade the capacity to 1000MW, with an additional 7.2 GWh of storage