Western Australia’s Economic Regulation Authority (ERA) has fined Synergy $1.2 million after finding offers for energy from its Kwinana big battery caused inflated prices in the Wholesale Electricity Market due to a trading software error.
The ERA estimates Synergy’s over-pricing of its offers increased wholesale energy costs by approximately $9.5 million across a period of eight months starting in late 2023, with Synergy gaining around $850,000 in revenue.
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Synergy corrected the software error as soon as it became aware of it, working cooperatively with the ERA over the course of the investigation and admitting 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.
As well as being the state’s largest energy retailer, Synergy is also the largest generator in the Wholesale Electricity Market, producing around 28% 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.
ERA chair Steve Edwell said, “The ERA exists to ensure that vital utility services like electricity are delivered as efficiently as possible, to protect the long-term interests of Western Australian consumers.
“The penalty we have imposed on Synergy recognises that the breach was due to a software error and was not intentional, Synergy’s acknowledgement it has breached the market rules, its cooperation, and the steps it took to fix the software algorithm on discovering the malfunction.
“However, this action serves a reminder to all companies participating in the wholesale market that non-compliance, even when accidental, is not acceptable.
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“This is our fourth serious finding against a generator since August 2025. We are closely monitoring the bidding behaviour of all participants in the wholesale market, and where we see non-compliance, we will take action.”
