SSEN Transmission has today announced its Fort Augustus and New Deer substations will see the use of new, more environmentally-friendly gas-insulated equipment, demonstrating the company's commitment to reducing the environmental impact of its activities.

As part of its forthcoming projects at Fort Augustus, Inverness-shire, and New Deer in Aberdeenshire which both start in April, SSEN Transmission has signed a contract with a GE/Amey consortium which will see the installation of GE's gas-insulated switchgear and busbars utilising g3 gas in place of SF6 (sulphur hexafluoride).

Due to its extremely good insulating properties, SF6 gas is widely used in substations across the globe, with the transmission industry accounting for around 80% of the world's usage.

However, it is also a greenhouse gas with a Global Warming Potential [GWP] 22,800 times that of CO2 which stays in the atmosphere for around 3,200 years. Strict regulations control the use of SF6 gas, which are encouraging the utility industry to reduce its usage to help meet climate change objectives. GE's development of a greener alternative gas can reduce the environmental impact of such systems by as much as 99%.

  • With g3-insulated busbars (GIB) measuring over 1km, the New Deer site will see the world's largest volume of the gas installed at one location.
  • The Fort Augustus substation expansion will be the first transmission site in the country to have a fully g3-insulated substation and also a significant length of g3-insulated GIB.

Commenting on this major breakthrough for the industry, Dave Allan, SSEN's Technical Engineering Manager, said:

"As a responsible developer, we are determined to do everything we can to reduce the environmental impact of our activities. While our most material contribution to action against climate change is our role in enabling the transition to a low carbon economy, we are also determined to tackling our own emissions."

"By using this innovative new gas at Fort Augustus and New Deer, not only are we reducing the environmental impact on our own network, we are hoping that this will also demonstrate to the wider transmission industry that there is a viable alternative to SF6 out there, and one which they may consider using in similar scenarios in the future."

Dirk Uhde, Executive, GIS Product Manager, GE, said

"We are delighted to support SSEN Transmission in making significant reductions in the reliance on SF6 gas in high voltage switchgear. Fort Augustus is the first substation using both 145kV g3 switchgear and 420kV g3 gas-insulated busbar. New Deer is the longest 420 kV g3 GIB ordered to date. Using g3 instead of SF6 in those two substations will avoid the installation of approx. 200,000 tons of CO2 equivalent. That's equal to removing 43,500 passenger vehicles from the road for one year. Our latest switchgear not only utilises g3 instead of SF6 but also features the most compact dimensions in the industry. Consequently, the product's Life Cycle Assessment (LCA) shows the lowest environmental footprint along the whole life cycle."

In June 2018, SSEN Transmission demonstrated its commitment to supporting local and global efforts to tackle the threat of climate change when it confirmed its ambitions to set a science-based target for reducing its greenhouse gas emissions. This is designed to ensure SSEN Transmission achieves a level of decarbonisation in line with climate science, consistent with the landmark Paris agreement.

Today's announcement further supports progress to achieving this vision, putting SSEN at the forefront of the GB transmission industry as the first company to use g3 in its transmission substation switchgear.

SSEN's environmental commitments were also highlighted in November last year when the energy regulator, Ofgem, awarded it 'leadership' status for its 2017/18 Environmental Discretionary Reward (EDR). EDR is an incentive for transmission owners to demonstrate a strategic environmental focus in helping facilitate growth in low carbon energy.