First-of-a-kind aerial survey of overhead lines completed to help reduce power cuts

In what is believed to be the first survey of its type and the largest in the UK, all UK Power Networks’ overhead power lines across the East and South East have been surveyed by high-tech radar planes.

The equipment illuminates targets with a laser and analyses the reflected light, revealing the exact distance of vegetation from overhead lines. If trees or other vegetation come into contact with power lines it can cause power cuts.

The highly accurate data from the survey – believed to be the first of its type and the largest undertaken in the UK – has enabled the company to devise a three-year tree cutting programme in areas where tree branches could touch or damage cables in high winds potentially causing power cuts.

UK Power Networks, which owns and operates the electricity networks in the East of England, London and the South East, teamed up with solutions specialist ADAS and aerial photography firm Bluesky to begin work on the survey in July last year.

Three fixed-wing aircraft mapped the 34,000 kilometres of overhead lines over a three-month period.

The information has been incorporated into a 3D web portal which can be viewed from desktop computers enabling UK Power Networks employees to carry out ‘virtual patrols’ of the network. This will save time and reduce the risk to employees who would otherwise have to carry out foot patrols, sometimes across difficult terrain including physical barriers such as rivers, ditches, livestock and numerous other potential hazards.

Nigel Hall, head of service development at UK Power Networks, said: “This innovative multi-million pound project is of immense benefit to our customers and to the company. The risk-based tree-cutting programme will help reduce tree-related power cuts for customers, with the additional benefit that it could be carried out without any disturbance to local landowners because it was done from the air rather than on foot.

“As a company it will help us get best value from our £19 million annual tree cutting budget, and the web portal will mean staff can carry out ‘virtual patrols’ from their desk, saving them time and reducing the potential hazards if they had had to walk the lines themselves.”

Roy Dyer, head of arboriculture in ADAS and manager of the ADAS contribution to this contract, said, “This has been a ground breaking contract. The combination of Bluesky’s technical ability and ADAS’ consultancy experience in managing vegetation near overhead lines enabled us to successfully deliver this challenging contract and improve the management and resilience of the overhead lines owned by UK Power Networks.”

Rachel Tidmarsh, managing director of Bluesky, added: “Prior to commissioning the LiDAR and aerial mapping project, UK Power Networks undertook regular manual surveys as part of its assessment of network resilience, but the capture of LiDAR and associated aerial photography for the entire catchment area allows for evidence-based decision making and long term planning, and provides a proven solution for other network operators.”