(Watch the archive film and the ‘insider view’ videos at foot)
It is still going strong five decades later, playing an important role in generating electricity to meet demand, while operator Scottish Power mulls plans to double its output in an electricity supply market vastly changed from the middle of the last century.
The station stores water in an upper reservoir, ready to release and generate power when demand from homes and businesses is high. When demand is low, Cruachan takes surplus electricity from the grid to pump water from Loch Awe back up to the reservoir. It helps to balance supply and demand on the national grid.
Cruachan can produce electricity for the grid in two minutes – or 30 seconds if its turbines are already primed. This flexibility means that National Grid often calls on Cruachan to support peak demand from homes and businesses, typically at breakfast and tea time.
At full power, Cruachan can meet the electricity needs of more than 200,000 homes. However, unlike other power stations, Cruachan can also act as a ‘battery’. When the turbines are reversed they use excess electricity from the national grid to pump water back in to the upper reservoir, ultimately storing this energy.
Hugh Finlay, Generation Director at Scottish Power, said; “It was a prodigiously complex feat of engineering to design a power station buried deep inside a mountain, and it was a herculean task to construct it.
“The genius of Sir Edward MacColl’s initial design, coupled with the skill and determination over six years from the 4,000 strong workforce, ensured that Cruachan Power Station was built to last. It is as important today as it was 50 years ago.
“Scottish Power has invested significantly in Cruachan, meaning the station will play a pivotal role in supplying electricity in Scotland for decades to come.
“We are also investigating the potential of doubling the capacity of the station, because we believe that pumped storage hydro power plants can have an even bigger role to play in supporting the growth of renewable energy.”
By the banks of Loch Awe, a plaque pays tribute to the 36 people who lost their lives working during the construction of Cruachan. The story of those men and all of the workers who built the power station is told on a daily basis to the thousands of visitors who tour the station every year.
To mark the 50th anniversary, a radio play has been commissioned that will be recorded live inside the power station and broadcast by the BBC.
A spokesman for Scottish Renewables – which is lobbying the government for more Scottish hydro power stations to be built – said: “Cruachan allows electricity produced at times of low demand to be stored, then deployed when it is needed.
“The ‘Tunnel Tigers’ who built the scheme 50 years ago might not have foreseen the changes that would take place in our energy system over the next half century but it’s a testament to their engineering skills that the legacy they have left is now playing a vital role in combating climate change and keeping our lights on.
“Renewable energy produces more electricity than any other source in Scotland, and the importance of schemes like Cruachan is continuing to increase as we seek to find energy storage solutions to reduce the amount of C02”.
Queen opens Cruachan hydro power station in 1956:
Inside the ‘hollow mountain’ where the Cruachan hydro power turbines operate: