The Economic Regulation Authority has fined Synergy $1.2 million after finding the company in breach of the rules that govern Western Australia’s Wholesale Electricity Market.
After a detailed investigation, we have found Synergy’s offers for energy from its Kwinana big battery caused inflated prices in the Wholesale Electricity Market, due to an error in Synergy’s trading software.
We estimate that Synergy’s over-pricing of its offers increased wholesale energy costs by approximately $9.5 million across a period of 8 months starting in late 2023, with Synergy gaining around $850,000 in revenue.
The ERA’s penalty amount of $1.2 million takes into account the revenue gain made by Synergy, the length of time over which the conduct occurred, the material impact on market costs, and Synergy’s efforts to rectify the software failure and cooperate with the ERA.
As well as being the State’s largest energy retailer, Synergy is also the largest generator in the wholesale market, producing around 28 per cent of all electricity in 2025/26.
Under the rules governing the wholesale market, companies bidding to sell their electricity are required to do so at no more than their reasonable cost of producing that electricity.
Synergy corrected the software error as soon as it became aware of it. It has worked cooperatively with the ERA over the course of this investigation and admits the breach.
As part of the ERA’s decision, Synergy is also required to provide full details of the software solution put in place to remedy the error and, if the ERA decides it is merited, submit the solution to an independent audit.