The Australian Energy Regulator has launched federal court action against a power station operator in Adelaide over its conduct ahead of the 2017 blackout which cut electricity to about 90,000 properties.

The regulator alleges the operators of the Pelican Point gas-fired plant failed to notify the Australian Energy Market Operator of its generating capacity at a time when South Australia was experiencing heatwave conditions, high customer demand and reduced power availability.

Those conditions led the operator to order load shedding to take about 30,000 users off the network on 8 February that year.

However, a computer glitch meant the distribution company SA Power Networks actually cut power to 90,000 properties.

“The AER alleges that Pelican Point did not disclose to AEMO that one of the generators at its Pelican Point power station was capable of being made available on 24 hours’ notice,” chair Paula Conboy said in a statement on Tuesday.

“We allege that until late in the afternoon of February 8, 2017, AEMO was unaware it had the ability to issue a direction to Pelican Point to make the full capacity of Pelican Point power station available.

“As a result, AEMO’s ability to manage power system security was impaired.”

The AER is seeking declarations, penalties and costs but Engie, which operates the Pelican Point facility, said it rejected the allegations and would defend the claims.

The action against Pelican Point follows similar court proceedings launched by the regulator against four SA windfarms over failing to perform properly during the 2016 statewide blackout.

In that action, the AER alleges AGL Energy Ltd, Neoen SA, Pacific Hydro Ltd and Tilt Renewables all breached the national electricity rules.

The allegations relate to the performance of windfarms during the severe weather event that swept across SA and which ultimately triggered the statewide power outage.

The storms damaged more than 20 towers in the state’s mid-north, bringing down major transmission lines and causing a knock-on effect across the state’s energy grid.

About 850,000 customers lost power, with some in the state’s north and on the Eyre Peninsula left without electricity for several days.

Conboy said accurate generator capacity information was critical for AEMO to properly manage the national grid.

“As we head into summer, it is important that generators provide AEMO with timely and accurate information about their capability to ensure that AEMO can manage system security and keep the lights on for Australian consumers and businesses,” she said.