Pumped hydro plant operator applies for 600MW expansion project in Scotland

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The dam at the Cruachan pumped storage plant. Image: Drax.

UK power generation company Drax has announced plans for a new underground pumped hydro storage power station, and will seek planning permission to expand its Cruachan site in Scotland to 1.04GW.

The 600MW power station will be built inside Argyll’s highest mountain Ben Cruachan, alongside the company’s existing 440MW pumped storage hydro station dubbed the Hollow Mountain. The two will share the existing upper reservoir, as it has enough capacity for both at 2.4 billion gallons of water.

A new, hollowed-out cavern will be constructed, with more than a million tones of rock excavated to create the space within the mountain.

When constructed, the site will provide stability services to the power system, acting as a giant water battery. This will help cut energy costs by reducing the need to turn off wind energy generation due to system constraints – for example 3.6TWh of wind power was curtailed in 2020 according to analysis from Lane, Clark and Peacock – and thus unlock more renewable electricity capacity, said Drax’s CEO Will Gardiner.

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“Last year, the UK’s lack of energy storage capacity meant wind farms had to be paid to turn off and we lost out on enough renewable power to supply a million homes. We need to stop renewable power from going to waste by storing it, and Drax is ready to move mountains to do just that,” he added.

The company must now secure consent under Section 36 of the Electricity Act 1989 from Scottish Ministers to move forwards with the project, which it expects to take about a year from the application’s submission. The first phase of this includes public consultation, which Drax will open on the project’s website from 1 July, with further consultation events held later in the year.

In addition to Section 36, Drax has stated that updated policy and market support mechanisms from the UK Government will be needed for the expansion to come to fruition.

To read the full version of this story, visit Solar Power Portal.

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