Extreme weather led to the embarrassing state-wide blackout that plunged South Australia into darkness last week, a preliminary report has found.
Australia's Energy Market Operation (AEMO) says severe weather led to the state's main power interconnector with Victoria overloading last Wednesday.
The loss of three major transmission lines and 315 MW of wind generated power in the storm increased demand on the Heywood interconnector, the AMEO found.
It then shut down to protect itself from damage, cutting all SA's power.
Power returned to Adelaide within hours but the blackout lasted longer in regional areas.
The AEMO report said it is not yet clear whether SA's power systems were working as they should have been at the time.
"The root cause is subject to further analysis ... and additional information that may be provided," the report said.
"Insufficient analysis has presently been undertaken to determine if everything operated as designed during the event."
The AMEO will release a more detailed report and a set of recommendations.
Premier Jay Weatherill said AEMO's initial report proved the blackout was due to weather, not renewable energy.
Renewable energy makes up 41 per cent of SA's power mix, more than any other mainland state.
Mr Weatherill accused Prime Minister Malcolm Turnbull and SA Liberal Leader Steven Marshall of "politicking" by overstating the influence of renewables.
"Malcolm Turnbull, our PM, took the first opportunity to lecture South Australians about the dangers of renewable energy and for the Labor states in promoting unrealistic renewable energy targets," he said.
"Now this was information that was made ... in contradiction of the oral advice that we were receiving from the Australian Energy Market Operator.
"It's deeply disappointing that we do not have the national leadership which is necessary to deal with this and other issues."
Mr Turnbull told reporters on Wednesday Mr Weatherill still had a case to answer to "keep the lights on" in his state.
"What we need to do across all levels of government is this - we have to deliver energy security. Rule one - keep the lights on," he said.
"Second, we have to ensure energy is affordable. SA has the highest wholesale energy costs in Australia.
"So that is a problem for SA and the government. Mr Weatherill has to answer for that."
SA opposition energy spokesman Dan van Holst Pellekaan said there is "no doubt" the state government's rush towards "intermittent" renewable energy had played a role in the blackout.
He has called for a separate, independent inquiry into the incident.
The prevention of more blackouts in SA will be among the issues discussed when Australia's energy ministers meet in Melbourne on Friday.