Australia's Chief Scientist Alan Finkel is looking to cap the take-up of intermittent wind and solar power in the states while technologies to stabilise the national electricity system are developed to prevent blackouts.
The move puts Dr Finkel's electricity system reliability review on a collision course with Labor states such as Queensland and Victoria that are determined to surpass crisis-prone South Australia's 40 per cent renewable energy mix.
Dr Finkel told an energy forum last month it would be difficult to cap renewables in South Australia now because the horse has bolted and all the wind farms and other generators in the state were connected under existing rules.
"But as penetration increases in other states in Australia there is a case for thinking about just what level of instantaneous penetration you will allow in any given year in any given jurisdiction until you build up those supportive technologies," Dr Finkel said.
"And as those supportive technologies build up then the percentage can safely be elevated. So it's a manageable problem but it has to be managed."
Non-fossil fuel technologies that could help stabilise the grid include batteries and pumped hydro storage.
Energy politics boiled over last month when the Turnbull government ruled out emissions trading as a way of reducing carbon emissions and soaring electricity and gas prices are set to keep it bubbling this year.
Prime Minister Malcolm Turnbull and Energy Minister Josh Frydenberg last year urged Victorian and Queensland to abandon their 50 per cent renewable energy targets by 2030 and accept the federal target of 23.5 per cent by 2020.
Dr Finkel told a Grattan Institute-Melbourne University energy forum last month that "really high" rates of intermittent wind and solar power "take inertia out of the system" and make it "more subject to propagating failure if a generator disconnects or some other problem occurs".
"Spinning inertia" stabilises the frequency and voltage in the grid and has traditionally been provided by "synchronous" coal and gas generators, but South Australia's last coal-fired power station shut last May.
Dr Finkel is fast-tracking the part of his report that looks at how batteries can be used to provide "frequency control ancillary services" such as inertia after presenting to energy ministers on the subject on December 13. His final report on system security is expected in May.
In the meantime, the Australian Energy Market Operator has insisted since South Australia suffered a statewide blackout on September 28 that at least two gas turbine generators operate at all times in the coal power-free state, even at minimum capacity.
AGL Energy reversed plans to mothball four ageing gas turbines at its Torrens Island gas power station in June as power prices soared in South Australia and in July the state's Weatherill government had to lean on France's Engie to turn its Pelican Point gas plant back on.
South Australia pays much higher prices for electricity than other states and has suffered price spikes, the blackout and another major outage since its last coal-fired power station – Northern in Port Augusta – closed last May.
High gas prices also help to push up electricity prices because gas generation is last resort and sets the "marginal price" when the wind isn't blowing.
Dr Finkel told the forum that pumped hydro storage could also contribute to grid stability because "when that water comes downhill, it's turning an old fashioned synchronous generator".
Pumped hydro and batteries have mostly been considered as storage vehicles for wind and solar energy, which can produce surplus electricity on windy, sunny days and none at all at other times, often with little warning.
But South Australia's energy woes have highlighted the need for system stabilising services as well.
AEMO blamed a severe storm that knocked out transmission networks for the September 28 blackout. But the outages on December 1 that caused BHP Billiton's Olympic Dam mine to be shut down for a second time in as many months happened partly because the wind wasn't blowing in South Australia at a time when the state was cut off from Victoria's coal power.
"It's a really important issue and if you don't have all the solutions to the missing ancillary services that the old-fashioned synchronous generator would have given you," Dr Finkel told the Grattan-Melbourne University forum.
