ElectaNet installs four converters in 2021 to smooth out and boost South Australia's major solar and wind output

One of ElectraNet's synchronous converters being constructed at Robertstown. Inset: Official data showing South Australia's energy supply going from 100% wind  (green) to 100% solar (yellow) and back to 100% wind within 30 hours during October 2021.
Main image courtesy ElectraNet

Four big spinning machines – or synchronous converters – were installed in South Australia to make the power grid more secure and smooth out the state’s ability to draw on more renewables energy from rooftop solar and wind.

Two of the synchronous converters were deployed at Robertson north of Adelaide where a new transmission link to New South Wales would start, and two at Davenport near Port Augusta, where big wind and solar farms had replaced the state’s last coal power generators.

Electricity poles and wire company ElectraNet that installed the four synchronous condensers –  each more than 170 tonnes, eight metres long, five metres tall – said they would help energy regulators grapple with the renewables boom. The limits on wind and solar output would be relaxed, with up to 2,500MW allowed in certain conditions – against the previous limit of around 1700MW.

With the new coordinated use of synchronous converters operating, the Australian Energy Market Operator would have to rarely intervene in the market and order gas generators to begin production, even if the price was low. Australian Energy Market Operator interventions had cost $34 million in the 2020-21 alone, with a cost passed onto residential power customers.

The synchronous converters meant that gas generators might still be needed when there is not enough wind or solar to meet energy demand but the gas generation needed to maintain grid security will be largely reduced. Batteries operating in “virtual synchronous” mode also would be able to deliver the effect of the converters.

Despite the previous limits on output by South Australian wind and solar output, they supplied 62% of the state’s electricity demand in 2020-21. This share of large scale renewables, from what was already the world’s leading grid for wind and solar ,was likely to jump as the restraints were relaxed and new projects, such as the 317MW Port Augusta renewable energy park – combining wind and solar – started production.

The South Australian  government has a target of reaching “net 100% renewables” by 2030, but most experts say this would likely be achieved well before then.

One of ElectraNet's synchronous condensers during construction at Robertstown.(ElectraNet)