Solar pushes demand in South Australia to new record low

In a clear demonstration of Australia’s energy transition, South Australia (SA) has set a new record low for grid demand as both rooftop and utility-scale solar ramped up production over the weekend. On Sunday 12:30 p.m., favourable weather conditions, coupled with low weekend demand, meant that SA set a new record for lowest operational demand at 475 MW, the Australian Energy Market Operator (AEMO) said.

The announcement comes only a week after the state had set a previous record low for operational demand, which defines as the amount of power consumers require from Australia’s wholesale energy markets. This does not include power generated by behind-the-meter resources, like rooftop PV, which has already proven itself as a key driver behind these new records, along with energy efficiency.

“At the time of the new record, rooftop solar was generating approximately 821 megawatts of power, which equalled 64% of the total demand required in South Australia,” AEMO’s Chief Operations Officer, Damien Sanford. “If you add in power generated by utility solar and wind generation, approximately 90% of the state’s native demand was met by renewable sources.”

Explaining the reasons behind the phenomenon, Sanford noted that rooftop PV usually has its maximum output during the middle of the day, when many people are not at home, and in particular when the weather is mild, like over the previous weekend.

However, AEMO notes that such new records are not only exciting but also challenging when it comes to managing key system requirements, like frequency and voltage. “System security is AEMO’s highest priority,” said Sanford. “That’s why we’re working closely with industry members on several market and technical trials for distributed energy resources, like virtual power plants, to understand how we can better utilise the increasing amounts of behind-the-meter resources we have today.”

With around 1 GW of small-scale solar PV on the SA grid at the end of June, the time of minimum demand has shifted from the early morning to the middle of the day. AEMO noted in its Quarterly Energy Dynamics report that this shift is limited to SA at present, while for other NEM regions, the overnight period remains the lowest demand part of the day.

With the substantial help of its rooftop PV fleet, SA is moving towards its 2030 target of “net” 100% renewables. As a testbed for future scenarios of high renewables penetration, the SA electricity market remains under the close watch of the market operator. Last year, AEMO projected SA would have 73% renewable power by 2020/21.