Scotland could be on the verge of a new generation of hydro power to rival the revolution in the glens which saw electricity taken to the Highlands in the 1950s.
Scottish Power has just announced that it is to consider more than doubling the capacity of the pioneering Ben Cruachan pump storage station – the world’s first high head reversible pump storage hydro scheme, housed in a gigantic man-made cavern, the famous ‘hollow mountain’.
Welcoming today’s announcement while on a site visit to see the scale of the technology involved in Iberdrola’s Cortes La Muela scheme, Europe’s largest pump storage facility, First Minister Alex Salmond says: ‘Combined with other planned developments around Scotland, this major announcement today heralds a renaissance in hydro and pump storage energy, and opens another chapter in our outstanding history of harnessing renewables.
‘In 1945, fewer than half of the homes in the highlands had access to electricity. By 1959, that proportion had increased to over 90 per cent through the forethought and leadership of Tom Johnston, who led the hydro-electric revolution.
‘Today, the Scottish Government recognises the potential for future development at Cruachan and other similar proposals for hydroelectric storage, to contribute to a balanced mix of energy generation across Scotland. This could see hydro power generate up to one third of Scotland’s entire generating capacity in the next decade.’
Hydro investment in Scotland in 2012 was estimated to be more than £25 million. Since 2007, the Scottish Government has consented 20 hydro applications, with a total installed capacity of just over 720MW.
An expanded Cruachan could generate a total of 1040MW compared to its existing capacity of 440MW.
Scotland was the one of the first countries in the world to harness electricity from its waters. That legacy is still visible. This ambitious post war hydro building programme resulted in infrastructure which still produces electricity today.
Pump storage systems are effectively large batteries consisting of two bodies of water [reservoirs] at different heights. At Cruachan, the mountain top dam is one of these reservoirs and Loch Awe below serves as the second. If the entire upper reservoir were pumped through the turbines and out into Loch Awe, it would make no more than a fraction of an inch difference to the level of this huge loch.
During periods of high electrical demand, the stored water is dropped down through the turbines below to generate energy at once.
During periods of low demand for power, surplus electricity is used to pump water from the lower reservoir to the upper reservoir. This is done at night when electricity prices are lower, with the stations profits made from selling its power output at peak prices and paying lower prices to replace the resource.
Pumped storage has the highest efficiency of all technologies currently available. It is the only the only technology that can be deployed at large scale.
Cruachan has installed capacity of 440MW and has been fully operational since 1967. It is the world’s first high-head reversible pumped storage power station. It attracts 60,000 visitors a year to its ‘Hollow Mountain’ visitor centre and cafe on the shores of Loch Awe. In 2012 Cruachan received the Institution of Mechanical Engineers’ Heritage Award.
Early studies carried out by ScottishPower and Iberdrola engineers have identified that it may be possible to construct a new cavern within Ben Cruachan, and expand the reservoir above, with the potential to increase the capacity of the station from the current 440 Megawatts (MW) to 1040 MW.
The redevelopment of the station would take between 8-10 years and up to 1,000 workers could be employed at the peak of the main civil construction works.
