For almost 55 years the Cruachan Power Station has provided electricity storage for the grid by using its turbines to pump water from Loch Awe in the glen below to an upper reservoir built on a plateau a short way up Ben Cruachan mountain. The stored water can then be released back through the turbines to generate power quickly when demand increases.

The plant’s 440MW capacity provides high levels of flexibility for the grid, which has proved particularly useful during the coronavirus lockdown when low electricity demand in Scotland coincided with periods of high wind power, according to Drax.

Last month, Cruachan to provided critical support services to National Grid Electricity System Operator (ESO), which is responsible for balancing electricity supply and demand services in the UK. Such power storage and flexibility services are becoming increasingly important as the energy system shifts towards more intermittent, greener forms of power such as wind and solar.

As such, Drax is investing £1m in modernising the power station’s turbine control system, replacing its existing programmable logic controller computer system with a new design aimed at drastically boosting its efficiency.

“Cruachan plays a critical role in supporting renewable energy in Scotland and stabilising the electricity grid,” said Ian Kinnaird, Drax Group’s head of hydro. “As the country continues to decarbonise, the station’s flexibility has never been more important. This upgrade will ensure the Hollow Mountain can deliver the fast, flexible power that hundreds of thousands of homes and businesses rely on for many decades to come.”

The upgrade to the plant’s systems will be carried out by control system builders ITI, previously known as Servelec Controls. The firm has worked on the site since 1987, previously building a control system which enables the Lanark and Galloway Hydro Schemes to be remotely managed from a single interface located in Cruachan’s underground cavern.

“We’ve been working at Cruachan Power Station for over 30 years now, and in that time have developed a deep understanding of their assets, their systems and their operational requirements,” said Bryn Thomas, sales director at ITI. “It is these strong relationships with our customers that enable us to work with them on developing transformative solutions that enhance their operations, improve safety and support sustainable green energy production,”