The South Australian Energy Minister acknowledged high take-up of wind turbines and rooftop solar cells in his state was making electricity security “a complex matter”, in a letter to the Energy Market Commission in July.
“Issues with managing the transition are already emerging in South Australia,” the letter said.
Tom Koutsantonis wrote to commission chairman, John Pierce, on July 12, just days after the shutdown of transmission lines to Victoria saw South Australia’s wholesale power price spike from a year-long average of $60 a megawatt hour to $9,000.
The Minister’s letter proposed a series of changes to the national electricity market rules, “to manage security challenges that may emerge as Australia’s electricity supply transitions to a carbon constrained future”.
South Australia’s power woes have been in the spotlight since the entire state was blacked out last Thursday.
The Australian Energy Market Operator said it was caused by the catastrophic weather conditions and the system would have shut down no matter what the energy mix.
But with more than 40 per cent of South Australia’s power now wind-generated, and the balance split between high-priced gas and two transmission lines to Victoria’s brown coal plants, the outage has fuelled a furious debate about energy security.
In an article for the Australian Financial Review, Industry Minister Greg Hunt said, “The South Australian Government’s conscious policy to drive baseload energy out of the system meant the system collapsed further and faster than it would otherwise have done and recovered far more slowly than it should have”.
Mr Koutsantonis’s letter acknowledged renewables had forced conventional generators out of a market that could not operate without them, because their “synchronous” energy was still needed to ensure power system security.
40 per cent of SA’s energy comes from renewable sources
Synchronous power stabilises the electricity system’s frequency near a perfect balance of demand and supply: 50 hertz, or 50 cycles every second of every day. If the system spikes much higher or lower it shuts itself down.
“However, maintaining these services, or procuring suitable alternative services to ensure system security, is becoming a complex matter, given the high rates of installation of wind and rooftop solar PV and the withdrawal of traditional synchronous generators,” the letter said.
“Issues with managing the transition are already emerging in South Australia ahead of other jurisdictions in the national electricity market as there has been a substantial shift from conventional generation to renewable energy production with over 40 per cent of the state’s total generation coming from renewable sources in 2014/15.”
In an attachment to the letter the minister cites a February report by the Australian Energy Market Operator and Electranet – the owner of South Australia’s transmission services.
It warns that if the transmission lines to Victoria were cut at a time when there was little or no synchronous generation in South Australia then, “the potential consequence is a state-wide power outage with severe economic and possible health and safety impacts”.
The energy market operator is expected to release a report on the blackout soon, but in a statement last week said that “the root cause is likely to be the loss of the 275 kilovolt power lines during severe storm activity”.
It added that, “the reason why a cascading failure of the remainder of the South Australian network occurred is still to be identified”.
Australian energy ministers will meet on Friday, with Federal Minister Josh Frydenberg calling for jurisdictions to reconsider high state-based renewable energy targets in favour of a single national goal.