SA Power Networks is spending a million dollars a year insulating powerlines and upgrading infrastructure to ease bat-related blackouts, after Adelaide’s fruit bat colony ballooned to 36,000 at Botanic Park near Adelaide Zoo.
The Grey-headed Flying Fox colony that lives in the Adelaide Botanic Gardens is estimated to have grown to between 28,000 and 32,000 due to successive mild summers. Numbers have stayed consistent for the past three years, but an unusual early birthing pattern has seen us respond to more bat-related blackouts in January and February this year, than ever before.
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The Grey-headed Flying Fox is the largest bat in Australia and one of the largest in the world. A significant group of flying foxes, a protected species listed as vulnerable, arrived in South Australia in 2010 from the eastern states and established a permanent colony in the botanic gardens near the Adelaide Zoo. Their numbers have grown from around 10,000 in the early years to more than 28,000 now. As the colony has grown over the years, so have the number of power outages across the network.
The bats cause blackouts when they make contact between powerlines and pole top equipment, including insulators, transformers and switches or when caught by lightning arrestors. When this happens, the outages can vary anywhere from 60 seconds to two hours, depending on whether or not SA Power Networks needs to inspect powerlines.
“We expect more outages to occur in coming months as the large number of juveniles start to venture out and forage for food,” SA Power Networks said in a statement.
“During 2021, about 240,000 customers had a power supply interruption linked to 82 outages involving Grey-headed Flying Foxes. This is a significant issue for us and our customers. We are actively working to minimise these power outages for our customers, and the risk of electrocution to the flying fox colony.
“To better understand the issue, we have been working closely with fauna rescue groups, the Department for Water and Environment and the University of Adelaide.
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“We have installed animal guards and insulation covering on some overhead equipment where repeat outages have occurred. Also, a program of “sectionalising” high-risk lines has helped reduce the number of customers impacted by these outages.
“We have a large distribution network across Adelaide and the random nature of outages involving bats, unfortunately makes it difficult to eliminate or minimise their occurrence. We continue to work on new strategies to minimise the impact of flying fox related outages.”
