A report into February's load shedding in South Australia has pointed the finger at the Australian Energy Market Operator (AEMO), finding the agency miscalculated the likelihood of a potential blackout.

Power was switched off to 90,0000 properties on the hot February evening when heavy use of air-conditioning meant demand outstripped supply.

At the time, AEMO said load shedding was the only option to prevent the risk of prolonged damage to infrastructure.

As demand peaked, electricity supply from over the border exceeded the secure equipment limit, prompting AEMO to order the load shedding.

But the report from the Australian Energy Regulator found AEMO underestimated the high level of demand and overestimated power output from wind generators.

"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 the following day forced AEMO to order a Pelican Point generator be switched on, which triggered special pricing arrangements that caused electricity wholesale spot prices to soar.

Adelaide's maximum temperature reached 41 degrees Celsius the day the load shedding was ordered.

An error by power distributor SA Power Networks saw three times as many customers switched off than what was ordered by AEMO.