Cruachan Power Station, near Oban, celebrates its 50th anniversary today (Thursday 15th October), marking half a century of powering Scotland's breakfasts and tea times from deep inside the mountain of Ben Cruachan.
Her Majesty the Queen presided over the official opening ceremony on 15th October 1965, six years after construction had started.
Widely regarded as an engineering masterpiece, and often referred to as The Hollow Mountain, Cruachan was devised by Sir Edward MacColl and was built by a workforce of 4000. Over 220,000 cubic metres of rock was blasted and drilled by explosives experts know as Tunnel Tigers, to create a cavern 1km inside the mountain to house the turbines and a network of pipes and tunnels.
Music: The Descent by Kevin MacLeod
The concept behind Cruachan is a lot simpler than the construction efforts required to make it a reality. 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 operation Cruachan can meet the power demands 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 ScottishPower, 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.
"The station has also been a major presence in the local community. Generations of families have worked there over the years, and Cruachan has only been a success because of their efforts. Hundreds of engineers and technicians and support staff have turned up to work every day deep inside a mountain to power our morning cups of tea and ensure we can watch our favourite TV shows.
"ScottishPower 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. Produced by Artangel, Master Rock premieres on BBC Radio 4 at 22:15, 17 October, and will be repeated at 14:15, 19 October 2015.
Maria Fusco conceived 'Master Rock' for three voices and live sound from the mountain, composed on site by Olivier Pasquet. Fusco's narrative gives voice to the ancient granite itself, and to two figures closely involved in the story of Cruachan: John Mulholland, one of the surviving tunnel tigers, and Elizabeth Falconer, the artist who made a vast mural inside the turbine hall to celebrate the opening of the power station.