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.
About Michael Bloch
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This morning my 5.1 kW system (postcode 5049) which is on VPP plan showed typical performance up to about 10:20 when the Tesla Powerwall 2 was fully charged, then the generation dropped about 25% seemingly to curb export to about 3 kW. Every time there’s a spike in house load such as boiling the 1.8 kW kettle, the generation spikes a bit, maintaining 100% battery.
Is this part of the curtailment?
I have no battery, but it looks like my enphase microinverters ceased generating around the same time. Just shortly before 10.
My Fronius Primo 5.0 1 system (installed 2019) has reported 3 times in the past 5 days a 102 error ‘AC voltage too high’.
Only today has it stopped the inverter from feeding back to the grid.
Been on Grid Services with my Powerwall 2 ( as per of Simply Energy VPP ) since late Sunday evening when power was restored to my suburb
This seems a lengthy period for this to happen , Tesla were no help when i called them, Simply Energy VPP team have not returned my calls- & not sure where to turn
This is the first result I have seen on the Web, is anyone able to advise?
SAPN’s over-voltage “fix” is doing weird things to my battery and inverter system. I measured over 258 Volts in the house when they started using this to force solar inverters into shut-down. The solar & battery covers the household loads and I usually export about 10kWh a day.
The over-voltage shut down the inverter, but the system then started importing from the grid despite a full battery! The solution was pretty simple – I just cut the grid-connection! – and now my appliances are not at risk of over-voltage failure either. (electric motors don’t like over-voltage at all)
SAPN and AEMO really need to think through this “fix” of theirs – it could result in some pretty nasty insurance claims…
Whilst I do understand the need to manage an isolated state grid during a difficult time, I do not understand why:
• Households are not at least able to use the power they generate BEFORE it is exported. That’s the first reason we have a solar system;
• I am being encouraged to consume as much power as possible to help stabilise [sic] the grid when I am being charged 40c a kilowatt for the pleasure instead of getting it for free;
• I have received no communication in the last seven days about when my system will be turned off or when it will be turned back on; and
• The mainstream media outlets are conspicuously quiet about thousands of households being forced to pay more for a failure to plan and maintain an ageing grid.
It is both baffling and curious that we are consistently encouraged to invest in more responsible management of the issues facing humanity but are so often met with mixed messaging and support from those we entrust our future direction.