SSEN Transmission have announced that it has awarded a contract to GE Renewable Energy (GE)’s Grid Solutions business to manufacture, deliver and commission a 420 kV Green Gas for Grid (g3) gas-insulated substation at its new Kintore 400 kV substation in Aberdeenshire, on the north-east coast of Scotland.

This contract will support SSEN Transmission in moving a step closer to reaching its carbon reduction targets by building the transmission infrastructure necessary to connect and transport renewable energy, while avoiding the addition of approximately 350 000 t of CO2 equivalent to the grid.

The 420 kV g3 circuit breaker at the core of the substation is being co-funded over a two-year period by the EU’s LIFE programme, which is dedicated to climate change. SSEN Transmission joined GE’s LifeGRID project earlier this year to contribute to the specification of the circuit breaker’s main performance requirements.

GE’s g3 technology is an alternative to sulphur hexafluoride (SF6), an insulating and switching gas that has been used for decades in high-voltage substation equipment. Identified as one of the world’s most potent greenhouse gas by the 1997 Kyoto Protocol, SF6 is estimated to contribute 23 500 times more emissions than CO2, if leaked, and can remain in the atmosphere for up to 3200 years.

While SSEN Transmission’s material contribution to action against climate change is enabling the transition to a low carbon economy, the Scottish utility is also determined to tackle its own emissions. The company has set an ambitious goal to cut its greenhouse gas emissions by one third by 2026, making it one of the world’s first electricity networks company to receive external accreditation for a Science Based Target in line with a 1.5°C global warming pathway.

GE's g3 products feature the same performance and reliability as SF6 equipment but with a greatly reduced impact on the environment over their lifetime. According to life-cycle assessments, based on international ISO 14040/14044 standards, their CO2 equivalent impact is reduced by 99%, compared to SF6. At the same time, because g3 products have the same compact dimensions as SF6 products, there is no increase in emissions during the manufacturing process due to additional material.

SSEN Transmission is one of 21 utilities in Europe – along with UK’s National Grid, France’s RTE and Germany’s TenneT – that have chosen GE’s g3 equipment to help reduce their greenhouse gas emissions. Together, these utilities are avoiding the addition of more than 900 000 t of CO2 equivalent to the grid.

The 420 kV g3 substation is SSEN Transmission’s fourth g3 order. Last year, SSEN Transmission ordered the construction of a 1 km long g3-gas insulated line at its New Deer substation, Scotland, as well as a 145 kV g3-gas insulated substation and a 420 kV g3 gas-insulated busbar for its Fort Augustus site, also situated in Scotland.

This technology is a culmination of dedicated research and development efforts from teams in France, Germany and Switzerland, in collaboration with the 3M Company.