The Cruachan Power Station (also known as the Cruachan Dam) is a pumped-storage hydroelectric power station in Argyll and Bute, Scotland. The scheme can provide 440 MW of power and produced 705 GWh in 2009. The turbine hall is located inside Ben Cruachan, and the scheme takes water between Cruachan Reservoir to Loch Awe, a height difference of . It is one of only four pumped storage power stations in the UK, and is capable of providing a black start capability to the National Grid. Construction began in 1959 to coincide with the Hunterston A nuclear power station in Ayrshire. Cruachan uses cheap off-peak electricity generated at night to pump water to the higher reservoir, which can then be released during the day to provide power as necessary. The power station is open to visitors, and around 50,000 tourists visit it each year. Location The power station is on the A85 road, about 8 km or 5 miles west of Dalmally, on a branch of Loch Awe leading to the River Awe, which is the outflow from the loch, at its NW corner. There is a seasonally open Falls of Cruachan railway station nearby. History Construction commenced in 1959, and the power station was opened by Queen Elizabeth II on 15 October 1965. The concept was designed by Sir Edward MacColl, who died before it opened. The civil engineering design of the scheme was carried out by James Williamson & Partners of Glasgow, and the main project contractors were William Tawse of Aberdeen and Edmund Nuttall of Camberley. Consulting electrical engineers were Merz & McLellan of Newcastle upon Tyne. At the peak of the construction, there were around 4,000 people working on the project. Thirty-six men died in the construction of the power station and dam, and the cost of the scheme was . About in 2021 value. Cruachan was one of the first reversible pumped-storage systems, where the same turbines are used as both pumps and generators. Previous pumped-storage systems used separate pumps with a network of pipes to return water to the upper reservoir, making them much more expensive to build than conventional hydroelectric systems. Cruachan is predated by the smaller Lünerseewerk (de) of 1958 and the Ffestiniog Power Station of 1963. It is one of four pumped storage schemes in the UK. Its construction was linked to that of Hunterston A nuclear power station, to store surplus