The operators of Telsa’s big battery, South Australia’s Hornsdale Power Reserve, have copped a $900,000 fine for falsely claiming it could handle back-up services to the power grid.

The Australian Energy Regulator took Hornsdale Power Reserve to the Federal Court for claims made in 2019 to AEMO, where the operator said it could provide “frequency control ancillary services” to keep electricity running in the case of power failures.

When an unplanned outage at Kogan Creek in Queensland hit the grid that October, the battery failed to control the power system frequency.

“HPR admitted it would have been unable to comply with its offers and provide those services during that period, despite being paid to do so,’’ the AER said.

“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,” AER chair Clare Savage said.

“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.”