ELECTRIFICATION IN MOTION

At Windyhill, GE Vernova is supplying SF₆-free 420 kV gas-insulated switchgear for a new SP Energy Networks substation designed to support a stronger, more resilient and more sustainable transmission network.

As more renewable power connects to the grid, transmission networks need to carry more electricity, manage changing power flows and maintain the reliability customers depend on every day.

For SP Energy Networks, this means strengthening the power transmission infrastructure needed to connect more renewable energy and support Scotland and Great Britain’s net zero ambitions. At Windyhill, near Glasgow, UK, that work includes a new 400kV gas-insulated switchgear substation using GE Vernova’s g³ SF₆-free technology.

The project brings together two priorities that increasingly define modern grid investment: building the infrastructure needed for more renewable electricity and lowering the carbon footprint of the grid itself.

Gas-insulated switchgear, known as GIS, is used in substations to control and protect the flow of high-voltage electricity. It is especially important where space is limited because it delivers high-voltage performance in a compact footprint.

At Windyhill, the new substation is planned to feature GE Vernova’s 420kV SF₆-free GIS, Type T155g, manufactured in Aix-les-Bains, France. The technology is part of GE Vernova’s GRiDEA™ portfolio, which brings together solutions designed to reduce the carbon footprint of electrical equipment while maintaining the performance and reliability required for critical grid infrastructure.

Reducing SF₆ in high-voltage networks

For decades, sulphur hexafluoride, known as SF₆, has been widely used in high-voltage electrical equipment because of its strong insulating properties. But SF₆ is also one of the world’s most potent greenhouse gases, making its reduction an important part of decarbonising electricity networks.

GE Vernova introduced its first product using g³ technology, an alternative to SF₆, in 2016. Since then, the technology has been deployed across Europe. At Windyhill, it is designed to deliver the same performance SP Energy Networks’ network requires, while significantly reducing lifecycle carbon impact compared with SF₆-based equipment. That balance matters. Transmission networks need lower-carbon technologies, but they also need equipment that can operate reliably at high voltage, in critical parts of the grid, over a long service life.

Supporting Scotland’s renewable power ambitions

The upgrade of Windyhill substation is part of SP Energy Networks’ wider work to reinforce the transmission network in central and southern Scotland,and prepare it for a cleaner, more electrified future.

Technologies such as SF₆-free GIS are becoming increasingly important for Transmission Systems Owners across the UK. They allow operators to build high-performing networks while reducing the carbon footprint of the infrastructure itself.

The project also supports SP Energy Networks’ Sustainable Business Strategy and its RIIO-T3 Business Plan for 2026 to 2031, which focuses on connecting more renewable energy, supporting Clean Power 2030 and creating long-term value for customers and communities.

A step forward for lower-carbon transmission infrastructure

The Windyhill agreement is an important milestone because it confirms the use of SF₆-free GIS technology for a major 400kV transmission substation in UK.

For GE Vernova, it reinforces the company’s role in supporting utilities as they modernise and decarbonise power transmission networks. It also shows how SF₆-free high-voltage technology can support critical 400kV transmission applications while maintaining the reliability, resilience and compact footprint grid operators require.

At Windyhill substation, SP Energy Networks and GE Vernova are advancing a transmission project that reflects where grid investment is heading: stronger networks, more renewable electricity and lower-carbon infrastructure built for long-term performance.