AusNet Services – Cost pass through – 500kV Transmission Line Tower Collapse

Commencement date: 
10 July 2020
Effective date: 
1 April 2021
AER General Inquiries
AER reference: 


On 29 September 2020, the AER released its decision on AusNet Services' 500kV transmission line tower collapse cost pass through application. AusNet Services’ application relates to $25.8 million ($2020-21) in additional costs AusNet Services has incurred and will incur to restore transmission services and replace collapsed 500kV dual circuit transmission line towers on the Moorabool–Mortlake and Moorabool–Haunted Gully transmission lines in south western Victoria as a result of an extreme weather event that occurred on 31 January 2020.

The AER determined that AusNet Services’ application satisfied the definition of a natural disaster event in AusNet Services’ 2017–22 revenue determination and a positive change event under the National Electricity Rules. The AER approved a positive pass through amount of $2.3 million ($2020-21) to be recovered from network users in the year ending March 2022.

The pass through will increase an average residential annual bill in Victoria by about 40 cents in 2021–22.


On 10 July 2020, AusNet Services submitted an application to the AER for a positive pass through of $2.3 million for costs associated with a 500kV transmission line tower collapse that occurred as a result of a severe weather event on 31 January 2020. AusNet Services proposed that the pass through amount should be recovered through an increase in AusNet Services' transmission revenue in the year ending 31 March 2022. The pass through amount for this period constitutes a small proportion of the actual costs of the event ($25.8 million), as the capital costs incurred will be recovered over the life of these long lived assets.