The operator of South Australia's Tesla big battery has been fined $900,000 after a software glitch left it unable to help stabilise the grid.
Hornsdale Power Reserve (HPR) was ordered on Tuesday to pay the penalty after being taken to the Federal Court by the Australian Energy Regulator.
The court heard HPR had breached national electricity rules between July and November 2019 after it made offers to the Australian Energy Market Operator and was paid to provide market ancillary services which it could not provide.
The contingency frequency control ancillary services are required to help keep the lights on following a power system disturbance.
AEMO brought the conduct to the regulator's attention following a power system disruption at Kogan Creek Power Station in Queensland in October 2019.
The disruption was not caused or contributed to by HPR.
An investigation by Tesla later identified a firmware update carried out in July as the cause of HPR's failure to provide its promised services.
Justice Anthony Besanko on Tuesday ordered HPR to pay a $900,000 fine in regards to several breaches of the national electricity rules.
He acknowledged submissions from HPR that the contraventions were inadvertent and the relevant payments had been repaid to AEMO upon request.
No actual loss or damage was caused by the breaches, he noted.
AER chair Clare Savage said the penalty sent an important message to the market at a time when many new operators were joining the grid.
"It is vital that generators do what they say they can do if we're going to keep the lights on through our market's rapid transition to more variable renewable generation," she said in a statement.
"It's what is expected by every household, small and large business across Australia when they pay their electricity bills.
"AEMO relies on accurate information and compliance with offers and dispatch instructions to ensure it can effectively stabilise frequency deviations."
The Hornsdale Power Reserve, near Jamestown in SA's mid-north, was regarded to be the world's first big battery.
The first 100 megawatts was completed in November 2017 with the facility subsequently expanded to 150 megawatts.
It draws its power from Neoen's adjoining Hornsdale wind farm.
