Rooftop solar delivers yet another record low in grid demand for South Australia

Rooftop solar has delivered a new low in South Australia’s electricity demand over the weekend – the third minimum grid demand record to fall in the state in a month, according to the Australian Energy Market Operator.

AEMO says a new minimum operational demand of 458MW was recorded at 13:30pm on Sunday November 10, replacing the previous summer minimum record set in December 2018.

The new low (the red dotted line in graph above) follows the October 21 record low of 475MW, which itself came one week after rooftop and large scale solar combined to deliver 80 per cent of South Australia’s total demand, and two weeks after the state set a previous record low.

“This is yet another minimum demand record… set in South Australia and a strong signifier of how rapidly Australia’s power system is evolving,” AEMO says on its Energy Live blog.

And while the record was achieved on a Sunday, AEMO stressed that the state’s major industrial businesses were at typical operating loads at the time.

AEMO defines operational demand as the amount of power consumers require from Australia’s wholesale energy markets, not including power consumed from behind-the-meter resources, like rooftop PV.

It’s not just South Australia experiencing changes to day-time demand. As we explain in this story – Negative pricing events hit record levels as solar takes big bite out of coal  – rooftop solar is eating out midday demand in other states too and across the grid in general.

As AEMO explained on Monday, increased rooftop solar generation in the state is lowering the middle of the day demand, and shifting both minimum and maximum operational demand to later in the day.

“While these new records are certainly attention grabbing, that does not mean they’re without challenges,” AEMO said in the blog post.

“The increasing contribution of behind-the-meter resources to our power system has meant that managing key system requirements, such as frequency and voltage, can become more difficult.”

It is looking to changes in the management of distributed energy resources, including new inverter standards and enabling as many as possible to be “connected” and then potentially controlled.

“AEMO continues to work closely with energy market participants, partners and stakeholders to understand and manage the impact of Solar PV proliferation on the network and how that is creating demand peaks and putting pressure on the electricity grid,” it said.

“As our industry continues to rapidly transform, we’re expecting more broken records (not just in South Australia) and further developments within our power system. It’s an eventful time for our sector!”