SSEN Transmission says its Aberdeenshire electricity substation is playing a vital role in stabilising the grid, through a cutting-edge project that marks a key step in work to build a network for clean energy.
The energisation of Quinbrook/Welsh Power’s synchronous condenser at SSEN Transmission’s Rothienorman substation (pictured) will help boost system inertia, which is historically a key source of grid stability delivered by fossil fuel sources but is not provided by wind or solar generation.
With the UK’s reliance on renewable power sources increasing in line with national clean power and energy security targets, finding alternative sources of inertia is crucial in reducing reliance on fossil fuel sources, while reducing power cuts caused by instability.
The synchronous condenser consists of a large rotor acting as a physical stabiliser to automatically compensate for sudden short-term changes in the system.
If a fault occurs on the electricity network, the condenser provides inertia by allowing system protection for fractions of a second, enabling generators to respond.
The condenser is owned by Quinbrook Infrastructure Partners, a specialist global investment manager focused exclusively on the infrastructure needed for the energy transition.
Quinbrook partnered with Welsh Power in the development of the project from concept through to commissioning.
It is among several projects being delivered by SSEN Transmission as part of the National Electricity System Operator’s (NESO) Stability Pathfinder programme – which aims to generate inertia and short-circuit power to the grid without using fossil fuels.
These projects are among the first so-called “grid forming” converters being used to improve grid stability in Scotland.
Grid forming is the ability of an energy source, such as solar, wind, or battery, to provide voltage and frequency support to the grid, especially during disturbances or outages – a crucial requirement to enable decarbonisation of the power supply in favour of clean energy sources.
Head of customer experience for SSEN Transmission Oliver Driscoll said: “The energisation of Quinbrook/Welsh Power’s synchronous condenser at our Rothienorman substation marks a milestone in work to create a secure and reliable electricity network for net zero, reducing our reliance on fossil fuel sources to provide grid stability.
“Delivering these connections is not straightforward, and the cutting-edge nature of the Rothienorman project presented challenges that will prove to be invaluable in informing our approach to future projects.
“I’d like to thank all the teams involved for their skill and perseverance over the duration of this highly complex project.”
Head of project delivery at Welsh Power Gareth Rees hailed the synchronous condenser as a “state-of-the-art” facility.
He added: “Now operational, it will provide much-needed grid stability services to the network, facilitate the deployment of more renewable energy projects, and ultimately save the consumer money.”


