Scottish Power today announced its intention to examine more than doubling the capacity of the iconic Ben Cruachan pump storage station – the world’s first high head reversible pump storage hydro scheme, housed in a gigantic man-made cavern.

The Scottish Government said 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.

Fully operational since 1967, Cruachan has installed capacity of 440MW. Early studies carried out by ScottishPower and engineers from Spanish parent company Iberdrola suggest 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.

Iberdrola recently completed a seven-year project to double the capacity of the Cortes La Muela pumped storage hydro plant near Valencia to 1,500MW.

The development of Ben Cruachan pumping station would be expected to take between 8-10 years and up to 1,000 workers could be employed during the main civil construction works at peak. The project would cost hundreds of millions of pounds.

Welcoming today’s announcement, First Minister Alex Salmond said:

“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.”

“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.”

The proposals to develop Ben Cruachan pumping station have been included in Scotland’s draft National Planning Framework as a potential national development.

National development status establishes the need for a project but does not grant development consent. Planning permission and any other necessary assessments and consents will still be required at the consenting stage. Since 2007, the Scottish Government has consented 20 hydro applications, with a total installed capacity of just over 720MW.

Plan could enhance UK's security of supply

Increasing pump storage capacity would further strengthen Scotland’s energy mix and potentially also enhance security of supply right across the United Kingdom. 

Alex Salmond commented:

“With electricity regulator Ofgem forecasting a narrowing gap between English electricity generation capacity and peak demand, Scotland’s position as a net exporter to the rest of the UK is increasingly important to ensure security of supply across the network. It is clean, green, renewable Scottish electricity that will keep the lights on.”

The First Minister welcomed the announcement while on a site visit to Iberdrola’s Cortes La Muela scheme, Europe’s largest pump storage facility, completed in 2013, to see the scale of the technology involved.