SA Rooftop Solar Shutdowns – What’s Happening Today?

Some South Australian solar owners may see their systems remotely shut down at times again today as work continues on electricity infrastructure repairs after Saturday’s storms.

Just to briefly recap, storms that rolled through South Australia on Saturday resulted in widespread blackouts; particularly in the Adelaide and Yorke Peninsula regions. Between the 423,000 or so lightning strikes, high winds and rain that hammered parts of the state, it was a real mess and for some continues to be.

Adding to the mess was transmission tower damage near Tailem Bend, which resulted in South Australia disconnecting (islanding) from the National Electricity Market (NEM).

Around 163,000 electricity customers; i.e., premises, were affected by the blackouts. Given the widespread damage and the nature of it, it’s been a huge task getting power back to everyone. As at around 6AM this morning, there were still 42 outages affecting 2,734 customers.

Knock-On Effects For Rooftop Solar

Home solar uptake in South Australia has been such that we increasingly have periods when there’s an abundance of surplus solar energy in the grid. We can usually export the surplus via the interconnector to Victoria. But with the interconnector out of action for the time being, that poses some additional challenges for maintaining grid stability here in SA.

Early on in the aftermath of this event, SA Power Networks (SAPN) warned it would need to bump some rooftop solar power systems offline at times as a last resort to maintain stability over the coming days. It has been using a couple of tools at its disposal to achieve this.

• Using remote disconnect/reconnect features built into inverters. This feature has been a requirement for all new solar installations in SA since September 2020.
• Artificially raising voltages in some sub-stations, which causes inverters to trip out.

The latter method is a *very* blunt tool; however, desperate times call for desperate measures as they say. But it’s caused a great deal of confusion/angst for some affected system owners, and some older systems have been doing whacky things.

Close to 300,000 small-scale solar power systems had been installed in South Australia before the remote disconnect/reconnect requirement came into play.

The Situation Today (Thursday, November 17)

There’s been all sorts of information and misinformation flying around as to what will happen today, which is expected to be a particularly challenging given very favourable conditions for solar energy generation – clear skies and reasonably mild temperatures.

Late yesterday, the Australian Energy Market Operator (AEMO) said steps will continue to be taken to maintain system stability, which include:

• Cancelling planned outages for transmission maintenance
• Increasing electricity demand by directing scheduled load into service or curtailing large-scale generation
• The South Australian Government voluntarily curtailing its solar generation.
• The curtailment of a proportion of commercial, industrial and residential rooftop solar generation.

“These are, however, challenging operating times and as such AEMO will undertake further assessment tomorrow as conditions emerge to manage system security”

I believe AEMO may have further instructions by around 8am today. We’ll update this post if anything of note is announced, or you can keep tabs on what’s happening on the AEMO’s Market Notices page.