Australia's renewable energy boom allows it to leapfrog the necessity of nuclear power, a new report says.

Upcoming inquiries in Victoria and on the federal level will look at the usefulness of nuclear power, but the report by progressive think-tank the Australia Institute finds the rapid development of wind and solar resources, particularly in South Australia, make new “baseload” power resources like nuclear uneconomic.

The National Energy Emissions Audit (PDF) found for almost two full days in July, South Australia met 100 per cent of its demand with wind and solar energy, and even had supplies left over for export to eastern states.

“What high renewables don't need is a baseload type of energy, so a consistent supply of energy that doesn't ramp up or ramp down to meet peak demand,” says Australia Institute climate and energy director, Richie Merzian.

“That usually happens when you have those extremely hot days in summer that are becoming more common.

“What our audit shows is the windows where you need that peak demand are few, but that's really where the additional support needs to come and that won't be provided by a baseload support like nuclear.”

He said nuclear energy costs too much and takes too long to build.

“It takes a long time to build and it doesn't complement high levels of renewables which is what we're seeing in South Australia and the direction we're going in in other states,” he said.

The Australia Institute's audit does acknowledge that South Australia's high renewable energy output forced the Australian Energy Market Operator (AEMO) to regularly intervene to maintain system security of the grid.

AEMO does this by ordering gas generators to run or for windfarms to curtail their output, or both, if the less consistent wind energy output upsets the stable operation of the grid.

However, the report finds that AEMO has been gradually reducing such interventions, suggesting it is becoming more experienced at dealing with the high renewable energy mix.

Mr Merzian says SA is setting a great example.

“What we found is that for nine of the last 18 months, half of all the energy supplied in South Australia has been from renewable generation, including rooftop solar,” he said.

“That means that South Australia has been able to operate for a good chunk of the last year and a half with at least 50 per cent of its energy coming from wind and solar.

“That's impressive and that's the highest in the country and is a real example for where most of the states are going to go.”

He noted Victoria and Queensland’s ambitious renewable energy targets, and that New South Wales is on track to become the largest generator of renewable energy despite not having a renewable energy target at state level.