The Australian Energy Regulator (AER) says the Australian Energy Market Operator (AEMO) miscalculated the likelihood of a blackout in February.

The regulator has been reviewing the disconnection of power to 90,0000 properties, which AEMO said at the time was the only way to prevent the risk of prolonged damage to infrastructure.

The AER says AEMO’s calculations were wrong.

“More accurate forecasts of both demand and wind generation may have led to earlier market signalling of a shortage,” the regulator's chairwoman Paula Conboy said.

“We understand accurate forecasting during extreme conditions can be particularly challenging but it is also critical to the effective operation of the market.

“Our role is to investigate these events in the market, ensure businesses and the market operator are meeting their obligations and identify where improvements can be made to drive better outcomes for consumers.”

Similar conditions forced AEMO to order a Pelican Point generator be switched on the next day, triggering special pricing arrangements that drove up electricity wholesale spot prices.