by Matt Thorpe, Head of Network Compliance, United Energy, CitiPower and Powercor
For the past seven years, Melbourne has been ranked the world’s most livable city – and as a Melbournian, it’s hard to disagree. For me, it’s the environment – the trees – that contribute to not just Melbourne’s reputation, but the state’s, as a great place to live and visit. But, as Head of Network Compliance at United Energy, CitiPower and Powercor, it’s Victoria’s leafy characteristics that also pose a challenge when it comes to managing our network.
We know vegetation can cause power outages, or worse, fires.
As an electricity distribution company, our priority is to continually improve the safety of our network for the communities we operate in, so vegetation management is an area that we focus on all year round.
We oversee three networks–United Energy, CitiPower and Powercor–that cater to customers from inner-city Melbourne through to rugged coastal hamlets and harsh dry plains in north-west Victoria.
In the Powercor network, we have some of the state’s highest bushfire risk areas, while our CitiPower and United Energy networks are home to suburbs that are made up of tree-lined streets that pose their own challenges when it comes to making sure vegetation is kept clear of our powerlines.
It’s our role to take all reasonably practicable efforts to minimise the chance of a branch or tree coming in contact with our power assets and causing outages or bushfires.
So how do we manage the risk posed by more than 10 million trees across our networks, which cover more than 70 per cent of Victoria, including some of the most bushfire-prone parts of the state? With the help of the latest technology.
Each year, several major network faults across Powercor, CitiPower and United Energy are caused by vegetation.
Most commonly these are a result of trees or other plants blowing into contact with powerlines during wild weather and we’re working hard to get that figure even lower.
That involves inspecting 400,000 spans (one span is the powerline between one pole to another) each year and cutting back vegetation at almost one-fifth of those sites.
Our commitment to safety
Energy Safe Victoria (ESV) guidelines regulate the industry, ensuring trees and vegetation are maintained at a safe clearance from powerlines.
When it comes to the required vegetation clearance distances, it’s not a one-size-fits-all approach.
ESV’s Code of Practice for Electric Line Clearance is calculated based on a range of criteria including whether the powerline is in a hazardous or low bushfire-risk area, the type of conductor, whether the powerline is high or low voltage, and the length of the section of powerline between power poles.
Special allowances are made where necessary, and considerations are made when assets fall within significant zones such as heritage sites.
Across our networks about 300 staff are employed directly and indirectly for vegetation management, executing on our carefully-considered vegetation management plan.
Technology now plays a vital role in collating and managing information across our enormous asset network.
Low-flying helicopter inspections and automation are helping us stay ahead of the challenge, particularly in our most fire-prone zones.
Three Bell 206 helicopters fly 250-500m above powerlines and use state-of-the-art Light Detection and Ranging Measurement (LiDAR) surveying equipment to scan the assets and vegetation.
LiDAR’s remote sensing method uses a pulsed laser to measure distances between a conductor and nearby vegetation to an accuracy of within 10cm.
The chopper-mounted measuring units send data back to specialist teams in the office for analysis and to determine what needs removal.
The process helps prioritise works required for the next fire season, and alerts us to any urgent work to ensure we can enlist immediate attention.
We’re industry leaders in using LiDAR as the sole inspection method for both hazardous bushfire-risk areas and low bushfire-risk areas, and the data is easily transformed into work instructions to enable cutting teams to do their work.
Since LiDAR was introduced, we have been able to detect hazardous trees more accurately, helping reduce the likelihood of vegetation causing outages.
Since December, we have been flying our helicopters across the western part of the state to get ready for the next fire season.
The weather may be cooling off, but for us the work to prepare for summer and the storm season happens all year round.
While the management of vegetation across our electricity network is challenging, the opportunities new technology is providing is fast transforming how we work and is an exciting part of the future.