The South Australian government is urgently seeking to restart two mothballed diesel-powered generators as it warns the state is at risk of blackouts this summer.

In July, French company Engie turned off its Port Lincoln and Snuggery peaking generators, ahead of its full closure in 2028.

Energy Minister Tom Koutsantonis has sought rule changes that would give the Australian Energy Market Operator (AEMO) the power to compel companies to bring decommissioned generators back online to support the grid supply during periods of high demand.

Mr Koutsantonis has warned the forecast for the reliability of power supply in SA this summer – which shows a predicted shortfall of 200 megawatts — has been underestimated because the AEMO has not accounted for the delay in a new interconnector with New South Wales.

The $2.3 billion project EnergyConnect will establish 900 kilometres of transmission lines between SA and NSW, allowing greater flow of electricity both ways.

It was due to be completed by July 2026 but is currently about 12 months behind schedule.

Mr Koutsantonis argued energy operators needed greater powers to bring back thermal generators "to address reliability risks arising during the peak demand periods expected from December 2024".

Speaking on 5AA radio on Monday, Mr Koutsantonis said: "given what happened in New South Wales last week, when they had one 40 degree day and they were nearly short on power, and told people to turn their air conditioners off and not turn dishwashers on, if we rely on an interconnector to New South Wales and it's hot across the entire national electricity market, we're in trouble".

The situation has exposed a "total lack of planning" by the state government, according to the opposition.

"They've known that these generators were withdrawing and mothballing back in February this year, and here we are the first week of summer and all of a sudden, the request has gone in to have these diesel generators to come back into the grid," said Shadow Energy Minister Stephen Patterson.

"The rush to renewables is one of the reasons why these generators are having to go out of the market more quickly than they otherwise would," he said.

Mr Patterson warned households will end up paying higher power bills while "at the same time, having low reliability".

Premier Peter Malinauskas denied the rapid uptake in clean energy in SA had seen a negative impact.

"The state government itself doesn't pay renewable operations, renewables are being invested in in South Australia because we've the best solar and wind resources anywhere in the world," he said. 

"We are on track to achieve our 100 per cent net-renewables target in 2027 regardless of this.

"In South Australia, we had something like 125 per cent renewables in the grid yesterday, we were exporting power, the spot price collapsed below 10 cents per kilowatt hour – because the sun was shining and the wind was blowing.

"What we've got to cover off on is when that isn't true, there is thermal capacity in the system – a firming service.

"Renewables firmed by fast-start gas, I think, provides the most likely set of conditions to provide affordable, reliable power to Australians in a way that is progressively being decarbonised.

"The problem has been there hasn't been enough fast-start firming capacity in the system." 

The Premier said the government was acting to "prepare for all eventualities" going forward.

"This isn't so much orientated ... towards this summer, but future ones," he said. 

"We want to see continued investment in generation across the state, and across the country, but for a range of reasons we've haven't seen that occurring at the pace we think is necessary.

"We will take whatever steps we need is necessary just to ensure there that there's insurance within the system."