Subscribe to Holyrood updates

Newsletter sign-up


Follow us

Scotland’s fortnightly political & current affairs magazine


Subscribe to Holyrood
by Will Gardiner, Drax Group
19 May 2021
Associate feature: Moving mountains to meet net zero

The dam at Cruachan reservoir

Associate feature: Moving mountains to meet net zero

As COVID-19 took hold last year and Britain first locked down, we faced unprecedented challenges.

The country’s health service faced a crisis. Many businesses were forced to shut down. You may be surprised to know that the UK’s electricity system was also facing unprecedented challenges to keep the country’s lights on so that hospitals and homes got the power they needed.

With millions of people furloughed or working from home, demand for electricity plummeted to the lowest levels seen this century.

You might think this makes managing the electricity grid easier, but just as a Formula 1 sports car is happier going at 70 than 20 mph, the national grid was forced to operate well outside its comfort zone.  

Supply and demand must always be equal, with the grid’s frequency knocked off balance if either suddenly plummets. Grid operators increasingly called upon pumped hydro storage power stations like Drax’s Cruachan in Argyll to stabilise the system as the country got to grips with the pandemic.

Cruachan is an underground power station built inside a hollowed-out cavern, 1km inside the mighty Ben Cruachan mountain.

The plant’s reversible turbines pump water from Loch Awe to an upper reservoir on the mountainside to store excess power from the grid. The stored water is then released back through the turbines to generate power quickly and reliably when demand increases.

This means the ‘Hollow Mountain’ acts like a giant water battery, storing power and then generating it fast when the country needs it most.

Across April last year, Cruachan’s four units shifted operating modes 969 times as they moved from pumping to generating or spinning to provide stabilising inertia to the grid.

These moments of managing high levels of renewable generation give us an insight into the energy system of the future.

While the lights stayed on this time, the system became more difficult to manage, which also led to more expensive energy for consumers. As we work towards achieving the Scottish Government’s target of operating a net zero carbon electricity system by the early 2030s, we need to invest in the infrastructure to enable it.

Drax has been progressing plans to build a new, additional underground power station inside the Cruachan complex. It would be the first newly built pumped storage power station in a generation – ensuring Cruachan can pave the way for more renewables to help the country meet its climate goals.

The project would be one of the largest infrastructure projects in Scotland in recent decades, creating jobs and bringing much needed investment to Argyll.

While the UK’s policy and market support mechanisms have evolved to support new build renewables, the current framework isn’t suitable for pumped storage projects that can have a lifespan of many decades. Indeed, no new pumped storage plants have been built anywhere in the UK since 1984.

By not supporting the creation of a new generation of pumped storage plants, the UK risks making the journey towards net zero more difficult and ultimately more expensive for consumers.

An independent report by academics from Imperial College London recently found that just 4.5GW of new pumped hydro storage could save up to £690m per year in energy system costs by 2050.

With the right support framework from the UK Government a new generation of pumped hydro storage power stations can be built, supporting new jobs and helping the country decarbonise faster.

To meet the country’s bold and ambitious climate targets, we need action and Drax is ready to move mountains to help achieve these.

Will Gardiner is CEO of Drax Group.

This article was sponsored by Drax Group.

Holyrood Newsletters

Holyrood provides comprehensive coverage of Scottish politics, offering award-winning reporting and analysis: Subscribe



Get award-winning journalism delivered straight to your inbox

Get award-winning journalism delivered straight to your inbox


Popular reads
Back to top