Cowi has been selected by renewable energy firm Drax to provide advisory services for the £500 million expansion of its Cruachan pumped storage hydro plant located in Argyll, Scotland. 

This expansion project, known as Cruachan 2, involves the construction of a new 600MW capacity facility adjacent to Drax's existing 440MW plant beneath Ben Cruachan. Following approval from the Scottish government in July, Drax aims to connect the new facility to the grid by 2030.

Cowi, in partnership with Studio Pietrangeli, will offer consultancy services to support preliminary engineering design work. It’s expertise will focus on technical guidance for the geotechnical marine structures and tunnelling aspects of the project. Additionally, Cowi will leverage its rail experience to assist in planning the railway line that will accommodate Cruachan 2's new access and tailrace tunnels.

The existing Cruachan power station, dating back to the 1960s, is one of only four active pumped storage facilities in the UK. The construction of the new station alongside it presents an opportunity to expand large-scale energy storage capacity while optimizing the use of existing assets, such as the Cruachan Reservoir and access roads, and minimizing disruption to the surrounding environment.

Cruachan 2 is a crucial step toward achieving the UK's goal of 30GW of energy storage by 2030. However, its realization hinges on the UK government establishing an updated financial stabilization mechanism for such projects. The absence of a framework for large-scale, long-duration storage technologies has prevented the construction of new plants in the UK since 1984, despite their pivotal role in the decarbonization process.