The figures behind our future - part 3

Electricity distribution network in the north of Scotland

With substations and underground cables at the heart of SSEN Distribution’s network infrastructure, it is crucial that our own Asset Management strategy supports SSE’s wider low carbon and sustainability strategies.

Our Sustainability Strategy for the next price control period (2023-2028) sets out how we will embed sustainability throughout our operations, and our Asset Management strategy ensures that effective decisions are made on our most environmentally sensitive assets. 

A key element of the strategy is a commitment to ensure a net positive impact on the environments we interact with, alongside no further degradation to our own local environments. In addition to this, we also have a regulatory obligation to reduce the impact of leaks on the environment.

As part of our drive to net zero, we have a Safety, Health and Environmental Improvement Plan, and this has identified two elements of our network where we can work to reduce environmental impact:

  • Fluid Filled cables (FFC) and,
  • SF(Sulphur Hexafluoride)

Fluid Filled Cables (FFC)

FFC are a legacy asset; these are no longer installed on our network, and our ultimate ambition is to replace them all by 2040. However, there is still an existing asset base to sensitively manage. 

The oil-filled cables on our network are strategic cables between substations supplying our customers at voltages of 33 kilovolts (kV) to 132kV and although FFC oil is not hazardous, if the oil leaks this could in some cases cause environmental harm.

Sulphur Hexafluoride (SF6)

SF6 has traditionally been used as an insulator in electrical substation equipment to prevent short circuits and accidents. Unfortunately, despite being an excellent insulator, SF6 is also a potent greenhouse gas. As a leading and responsible network company, it’s really important to us to be proactive in reducing SF6 leakage and to do so as economically as possible. 

Our Data and Analytics team, who specialise in analysing large sets of data and using machine learning, is using their expertise to gain insights into how we can reduce our emissions, including those from FFC and SF6. 

The team has produced a series of overviews which show the locations of all the Fluid Filled Cables and SF6, and in the case of the cables, whether these sit in sensitive areas (e.g. Sites of Special Scientific Interest). 

These Data and Analytics views have supported our Asset Management team by creating a risk model with a ‘risk score’ for each FFC, which in turn aids the identification of where necessary intervention is required.

And by creating a map that pinpoints each piece of equipment on our network that uses SF6 as an insulator, the team can analyse which assets might leak more SF6 than others to determine which require more urgent replacement. 

This will help us to drive our emissions down as quickly and efficiently as possible, starting with replacing the assets that have the biggest potential SF6 leakage. 

Using their skills and specialist expertise, our Data and Analytics team is keeping us on track to deliver electricity in a safe, reliable and sustainable way for our communities. 

About the author

Van on rural road

Scottish and Southern Electricity Networks

We're responsible for maintaining the electricity networks supplying over 3.8 million homes and businesses across central southern England and north of the Central Belt of Scotland. We own one electricity transmission network and two electricity distribution networks, comprising 106,000 substations and 130,000 km of overhead lines and underground cables across one third of the UK. Our first priority is to provide a safe and reliable supply of electricity to the communities we serve in Scotland and England.

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