The energy regulator is suing the company behind SA's big Tesla battery for allegedly failing to provide extra power to the grid during system disruptions, including leaving a Queensland power station in the lurch.
The Australian Energy Regulator has instituted proceedings in Federal Court against Hornsdale Power Reserve, 15km north of Jamestown.
Owned and operated by French company Neoen, HPR made offers from July to November 2019 to the Australian Energy Market Operator and was paid to provide frequency control ancillary services - required to keep the lights on following a power system disturbance.
The alleged conduct was first brought to the AER's attention following a power disruption at Kogan Creek Power Station northwest of Dalby in October 2019.
The AER alleges that the company's failure to provide the extra services created "a risk to power system security and stability".
AER chair Clare Savage said the regulator was sounding the alarm on "concerning" generator behaviour.
"It is vital that generators do what they say they can do if we're going to keep the lights on through the market's transition to variable renewable generation," Ms Savage said.
Ms Savage said contingency providers received payment from AEMO to be on standby to provide the services they offer.
"We expect providers to be in a position, and remain in a position, to respond when called upon by AEMO.
"Failure to comply with the latest market ancillary service offer and AEMO dispatch instructions is in breach of the National Electricity Rules and may result in AER enforcement action."
The AER is seeking penalties, declarations and costs.
Neoen Australia managing director Louis de Sambucy said the company was "disappointed" by the regulator's legal action.
"Whilst we are disappointed by the AER decision to commence proceedings, Hornsdale Power Reserve has and will continue to deliver important services for the electricity network and we will continue to work collaboratively with the regulator," Mr de Sambucy said.
Mr de Sambucy said HPR had played a key role in supporting system security a number of times, including the SA-Vic separation event in January and February last year and the recent Callide incident on May 25.
"On each occasion it has responded with its fast frequency response capability to reduce the severity of the disturbance and support a return to normal frequency conditions."
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