Expanding Cruachan Power Station: The Project

Why Expand Cruachan

Pumped storage provides extremely quick back-up during periods of excess demand or when other sources of generation are not available. For example, Cruachan can reach full load of 440MW in 30 seconds and can maintain its maximum power production for more than 16 hours if necessary. It can also help solve intermittency issues with other forms of renewable power, that is, when the wind doesn’t blow and the sun doesn’t shine. It also operates to help maintain stability of the national grid.

Expansion of Cruachan Power Station supports the Scottish Government goals for net-zero recovery by increasing generation output to complement increasing deployment of renewable energy to generate electricity. The importance of the expansion is reflected in the project having EU Project of Common Interest status and its recognition as a National Development under Scotland’s National Planning Framework.

Project Overview

The expansion project seeks to optimise the use of the existing Cruachan Reservoir and Dam through development of a new underground power station and associated infrastructure. The development would provide an expansion of the power generation capacity with a second pumped storage hydro-electric generation station which would operate independently of the existing Cruachan station.

A 2016 feasibility study indicated it would be possible to develop up to 600 megawatts (MW) of additional capacity at Cruachan Power Station. The study was published following the Scottish Government’s third National Planning Framework, setting out a long term vision for development and investment across Scotland over the next 20 to 30 years commented, “… we particularly support development at Cruachan in Argyll, a nationally important pumped storage facility with significant potential for enhanced capacity.”

Will Gardiner Drax Group CEO, said:

"This is an exciting and important project which underlines Drax’s commitment to tackling the climate crisis and supporting the energy system as it continues to decarbonise. Our plans to expand Cruachan will unlock more renewable electricity to power homes and businesses across the country, and support hundreds of new jobs in rural Scotland.

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.”

Cruachan Expansion Proposed Scheme

The Proposed Development seeks to provide an expansion of the power generation capacity of up to an additional 600 MW at the Cruachan pumped storage hydro electric generation station. Key components of the proposed development include:

  • Control works at Cruachan Reservoir and Loch Awe
  • A new underground waterway system to carry water between the upper and lower reservoir
  • A series of underground power-house caverns containing reversible pump-turbines and motor-generators
  • Above ground substation to provide a connection between the existing 275KV circuit that connects to Damally substation
  • Ventilation shafts
  • New quayside on Loch Awe adjacent to proposed lower control works
  • Above ground administration and workshop buildings for day-to-day operations
  • Access tunnels for health and safety and movement of power station personnel; and
  • Upgrades to existing service roads to facilitate access by heavy machinery.