SA Solar Shitstorm 2: Remote Disconnect

Solar power system shutdowns in SA

Image: Bru-nO

SA Power Networks has been given the green light to remotely and temporarily shut down solar power systems in “rare circumstances” from September 28. Here’s what it means for new and existing solar owners, as we currently understand the situation.

This authorisation has been granted out of concerns there may soon be times, particularly during spring, summer and autumn, when exports from solar power systems in South Australia outstrip electricity demand. In an electricity system, supply must match demand and vice versa – if that doesn’t happen, you start to see blackouts. SQ’s Ronald discussed the issue and “remote disconnect” of systems in greater detail back in May.

SolarQuotes founder Finn Peacock spoke with ABC Radio’s Sonya Feldhoff last week about SAPN’s new power.

Financial Impacts Likely Minimal, But…

Finn said while details were still sketchy, he wasn’t so concerned about the financial impacts it would have on solar owners as it would be measured in the “tens of dollars” per year in lost revenue and savings given how often remote shutdowns might occur and for how long.

“It’s not a good look politically to be switching off people’s money saving machines, so I’m very confident they are only going to do it when they absolutely have to.”

But Finn says how this is being implemented is quite another matter.

A “Really Horrible Solution”

“The Government I imagine is petrified of a major blackout this summer for political reasons and so they’re rushing through all sorts of policy on the run and more worryingly in my opinion, engineering on the run,” stated Finn.

Initially, this remote disconnect ability will only be for new installations of solar systems as special hardware needs to be installed for the functionality. There is a desire for all existing solar power systems to eventually be remote-disconnect capable, but the timeline for that isn’t clear at this point.

In the short term it appears what will happen in such incidents is the power to the solar inverter will be killed via an extra contactor installed in a home’s smart meter, which Finn says is a “really horrible solution for the problem”. This means not only will exports to the grid be interrupted, but the household won’t have use of their self-generated solar energy either – all of its electricity will need to come from the grid during these shutdown periods.

Finn said the much better solution, although harder technically, would be to send a signal to the inverter to say “hey, stop exporting to the grid”; but still enabling the system to generate just enough power to provide for the home’s needs.

Finn thinks medium- to long- term this will be the way remote disconnect will work, but the South Australian Government has been rushing into this with a ham-fisted approach for political reasons.

Remote Disconnect And Home Batteries

Another issue touched on was installing batteries to avoid loss of self-generated electricity supply in the case of a shutdown scenario. While it may seem a bit extreme to install batteries to avoid the impacts of what could be just a few hours a year, some particularly passionate solar owners may decide to do this.

“You’ve got to be careful what sort of battery system you get,” says Finn. “Some battery systems share the inverter with the solar, so if the government turns off your solar inverter, your battery system will go down too.”

Fin says he’s not clear on whether the government will allow people to have a battery on a separate circuit, but he would be surprised if they didn’t. Assuming it was allowed, you could design a suitable system, but the battery would need to have its own inverter.

Conspiracy Theory Debunked

Also discussed was a conspiracy theory that shutting down systems is a ploy to increase the cost of electricity by curtailing solar power supply.

“That’s not true, because the people that will be doing this are the networks and they are completely separated from the electricity retailers, who are the people who would make money.”

SA Power Networks is a distributed network service provider, not an electricity retailer.

You can catch the full ABC Afternoons with Sonya Feldhoff discussion here – it starts around the 37:30 mark and runs for approximately 13 minutes.

Solar Shitstorm 1 – Low Voltage Ride-Through

In other recent news out of South Australia, another “solar shitstorm” involves new inverters connected to the grid from September 28 needing to be verified as able to remain in continuous operation during brief undervoltage disturbances. Again, this isn’t so much of a case of being a horrible idea, but the execution has left a lot to be desired. Given the very short timeframe involved, it has created chaos in the SA solar sector – although some inverter manufacturers have already beaten the deadline, and hopefully more will.

Both of these issues are related to SA Government’s “Smarter Homes” push – and as previously mentioned, perhaps what SA really needs when it comes to managing solar power in the state is a smarter government.

About Michael Bloch

Michael caught the solar power bug after purchasing components to cobble together a small off-grid PV system in 2008. He's been reporting on Australian and international solar energy news ever since.

Comments

  1. Quote:
    ““That’s not true, because the people that will be doing this are the networks and they are completely separated from the electricity retailers, who are the people who would make money.”

    SA Power Networks is a distributed network service provider, not an electricity retailer.”
    /quote

    While I don’t subscribe to conspiracy theories, suggesting network service providers won’t have increased income isn’t correct.

    Every kWh delivered to homes incurs network fees per kWh (payable by retailers to the NSP) and this income stream goes up if households have to import more energy because their solar PV isn’t on. Retailer’s margin is quite small compared with the transmission and network fee.

  2. SA Power Networks is on a revenue cap, so it doesn’t gain from more volume of energy sales

  3. There is a really simple solution to this.

    – Reverse the metering of import/export (ie the counter for import goes towards the export amount and the import halts)

    So if a home owner was getting paid 10c per Kwh for export instead the energy company would pay the home owner 10c per KwH for import during the cut-off as they are now doing the grid a favor and stopping it melting down. The smart meter would just count the import at that time as export

    The grid operators would be far more careful to avoid the situation and for home owners with PV they dont loose out.

  4. Surprise surprise the Power Industry.lobbying for more controls! Grid spikes and excessive voltage are already commonplace in Vuctoria. The ultimate insult will be turning off our roof top systems at will! But again why arebwe surprised!

  5. david Warren says

    It is inevitable as more industrial scale solar PV and wind is brought online, domestic solar input will be curtailed so as to maximise profits for the bigger installations. it will eventually make sense to us domestic plebs, who have no power over the networks , to disconnect from the the grid altogether. I pay huge supply charges just to stay connected but still get a pittance for power supplied to them. The cost of power supplied by the big installations is less than we can supply it for, so no wonder we are being paid less and less. Pure economic sense.

  6. Rick Burnard says

    Our solar system shot down several times last season as there are now more home solar systems in our near area than not, and as a result, demand did not exceed supply . This apparently is controlled when the voltage in the surrounding network is higher than what can be pushed out by the solar system, and this causes the shutdown. Explained to me by Enerven person when I asked them to check.
    The issue, I understand is that solar power produced in a localised area cannot be sent via the network (through a transformer to another nearby area that still has demand.

  7. Hi Finn and Michael – thanks for your latest email update.

    Re the inverter low voltage issue, you mentioned that “some inverter manufacturers Have already beaten the deadline”.

    As I’m not quite in a position to go ahead with solar (and want to work to my own deadlines), can you be more explicit about which ones have complied.
    Or, if that nswer’s in danger of being out of date as soon as you send it, can you please confirm the question I need to ask. “Is your inverter verified so it can operate during under-voltage circumstances?” The next question is, “how would I know when I get a ‘yes’ answer!!!!

  8. Sven in Thailand says

    This is a way to turn customers that owns solar generation into into tools to regulate the network power, a quick response tool, and more or less free of charge for the power company, a very clever move by them to have it implemented, moving the cost for network regulation to the consumers.

    I will not buy a solar electric generation system until it is possible to use solar as a backup for power cuts without a battery connected. Neither will I bother with selling power to network. Zero power sent to network.

    Used large LIFePo4 battery cells from buses in China delivering 500Ah are starting to become a reasonable economical alternative as a souce for producing electricity during night and rainy days. An alternative way of getting electricity, if you live in the sticks, with unreliable electric network feeding you, often off for a day or two.

  9. Our solar system has been shutting down for two hours on business days for the last couple of weeks, usually during the peak generation period 11 – 1pm. Message from the inverter is “AC voltage too high”.
    Supplier has confirmed the inverter is working correctly as it should to protect itself. This information is valuable because I know that SAPN have infrastructure (known as Regulators and OLTC’s) whose specific purpose is to step down the voltage when it gets too high.
    I’m not a conspiracy theorist but I know that if SAPN chooses to it could remotely maintain the line voltage at a high level for any period of time and force solar inverters like mine to shut down creating the the appearance of solar oversupply. This would then force consumers to purchase grid electricity impacting our savings and benefitting retailers.
    In my mind this warrants some serious questions with respect to anti-competitive behaviour and blindness by AER.

  10. I believe that the installers of these big solar farms that are growing all over SA are the main reason for shutting down domestic solar systems so that they can continue generating without reduction. I hope that they are included in the shutdown process as well, along with the wind farms. I doubt that this will happen.

  11. Simple at peak demand they charge more for power so if you cut out the solar system on houses it means you will make money. When the demand is low the inverters cart feed in the power so the house holds cart reduce there bills. So it all about money and distroying small business. Well done sa government.

  12. Do I require wifi connected for solar pannels to operate on a new installation and if so ,why, and what happens if my wifi goes of line.

    • Ronald Brakels says

      WiFi is not required for a solar system to work, but is generally required for monitoring the inverter’s performance. If your WiFi drops out the solar system will continue to work without problem. But in South Australia changing standards mean new solar systems may be required to have a WiFi or other connection to the internet. I don’t currently know what requirements are for inverters that have their internet connection drop out. Clearly, that is something I need to look into.

  13. Thank you Ron,as we do not have wifi to the house and the cost of installing and using it would be more than the savings from the panels it is not feasible. At present we use mobile phone internet would this be considered adequate?

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