Cruachan Turbine Hall Drax Pumped Hydro
Drax announces £80 million investment in Scottish pumped hydro storage. Image: Drax

Renewable energy company Drax has announced plans to invest £80 million into the refurbishment of the Cruachan hydro power station in Scotland to reach 480MW of generation capacity.

Drax has appointed global hydropower technology supplier ANDRITZ, which has previously installed approximately 470GW of capacity, as the main contractor for the Cruachan upgrade project.

The project will see the generating capacity of two of the plant’s four units increased by a combined 40MW to raise the facility’s total generating capacity to 480MW.

Site works will commence in 2025, with ANDRITZ to install new main inlet valves and then unitised outages in 2026 and 2027 for units 3 and 4, respectively.

Pumped storage plants act like large water batteries, using reversible turbines to pump water from a lower reservoir to an upper reservoir, which stores excess power from sources such as wind farms when supply outstrips demand.

These same turbines are then reversed to bring the stored water back through the plant to generate power when the country needs it.

Drax’s investment is underpinned by the award of a 15-year capacity market agreement worth around £221 million.

The Cruachan upgrade project is separate from Drax’s plan to build a new 600MW pumped storage power station adjacent to the existing Cruachan facility; no investment decision has been made, and development remains subject to an appropriate regulatory framework.

The Cruachan site received development consent from the Scottish government in December 2023 and was awarded a capacity market agreement by the UK government in February 2024.

Drax’s interim COO, Penny Small, said: “Pumped storage hydro is vital to the UK’s energy security; it’s a technology which works in partnership with renewables.

“These plants play a critical role in stabilising the electricity system, helping to balance supply and demand through storing excess power. When wind turbines are generating more power than we need, Cruachan steps in to store the renewable electricity so it doesn’t go to waste.”

Managing director at ANDRITZ HYDRO Germany, Dominik Fust, said: “We are proud to have been entrusted with the refurbishment of the Cruachan Pump Storage Power Plant. This project aligns with our mission to contribute to the global transition toward sustainable energy generation.”

This article first appeared on Solar Power Portal’s sister publication Current±.