In just a few months, Ergon Energy and Energex will have the capability to remotely switch off some solar power and battery systems – but don’t panic.
Queensland is facing the same challenges elsewhere in Australia with rooftop solar power’s booming popularity – at some times of the day in some parts of some networks, too much solar energy is being exported and not enough electricity is being consumed. While these periods tend to be brief, they can cause network stability issues. As solar panels appear on more rooftops across the state, the management challenges will grow and become more widespread.
So, the Queensland Government is introducing a safeguard that will help maintain electricity system strength in instances where this may be threatened – the Emergency Backstop Mechanism.
How The Emergency Backstop Mechanism Will Work
New inverter installations 10kVA (10kW) and above will soon need to be fitted with a generation signalling device (GSD). This device will cost around $70 (wholesale), plus installation.
Connected to the inverter, the GSD will enable Ergon Energy and Energex to remotely switch off systems for short periods as a last resort in emergency situations to prevent blackouts when directed to do so by the Australian Energy Market Operator (AEMO).
The device responds to a signal sent over the power line, known as Audio Frequency Load Control (AFLC). These systems will be prevented from generating energy for self-consumption and export until the emergency has passed and network operators send another signal to the inverters to allow them to reconnect to the network.
A couple of important points to note – this requirement will not impact existing systems (with the exceptions below) and as mentioned, remote solar shutdowns will be a last resort. The emergency backstop mechanism will also only be applicable in areas where Energex and Ergon have AFLC available for signalling.
At this point, the generation signalling device will be required for:
- Any new connections with an aggregate installed inverter nameplate capacity of 10kVA (10kW) or greater.
- When replacing an inverter in such a system where the inverter is no longer under warranty.
- When adding capacity to a system if this results in the total inverter capacity being 10kW or greater.
- Where a system has (for example) two 5kW inverters and one is being replaced, the replacement will need the GSD.
When Will Generation Signalling Devices Be Required?
It’s intended the use of generation signalling devices will be required from mid to late November 2022. The exact date will be confirmed after a review of feedback from the consultation period. And on that note, Ergon Energy and Energex have provided further details on the emergency backstop mechanism and the proposed implementation arrangements in a consultation paper available here.
The feedback period closes on Friday, 7 October 2022.
The Emergency Backstop Mechanism is a blunt tool – but not the only tool to manage minimum demand risks. Among other measures being rolled out to strengthen system security in Queensland are big batteries on the transmission and distribution networks and the staged rollout of dynamic connections and dynamic operating envelopes. Dynamic connections are flexible arrangements where solar energy exports are “throttled” at the inverter level depending on network conditions at any given point in time.
Further information on Queensland’s emergency solar backstop mechanism can be found here.
Remote solar shutdown capability isn’t new – South Australia introduced remote solar disconnect/reconnect in September 2020 and as far as I’m aware the capability has barely been used. In February this year, Western Australia also introduced emergency solar management.
As SolarQuotes Founder Finn Peacock has previously commented, while too much solar at times can be a problem; it’s a good problem to have. If very occasionally there is too much solar energy, it means there is still plenty at other times of the day; pushing down or reining in wholesale prices and reducing electricity related emissions.
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Too much solar energy is being exported and not enough electricity consumed in Queensland? But isn’t that what’s supposed to be wanted?
Assuming no pool, no AC, and no solar, average consumption is about 9 kWh per day for a single person household, with solar dropping consumption to about 6 kWh per day.
Given current FiTs, daily supply charges, and usage charges, you need to export roughly 45 kWh per day to avoid being billed for power. That’s simply not possible with a 6.6 kW system, and only just possible barely more than half the months each year with a 13.3 kW system. Remember though this is single person household figures – 4 person households use roughly twice as much power so …
Thus either Queenslanders need to absolutely flood the grid with solar to offset their bills, or get stuck paying for electricity despite spending thousands on solar. Well unless you’re with Ergon – they at least pay a decent FiT.
Should FiTs stay ridiculously low, and electricity charges keep rising at 20% or so each year, then odds are households will simply opt to save money by dropping their grid connection and going for batteries instead. Will government and power companies be happier when solar owners cut the cable?
There lies the problem, the solar PV rollout has become a victim of its own success.
Solar FiT is low because of the impact that renewables has had on wholesale prices (in each state). But retail prices are high because of the other factors that are independent of generation/wholesale cost.
These are:
1. Transmission charges (TUOS) (about 0.2c/kWh)
2. Distribution charges (DUOS) (varies – from 4.5c to 20c/kWh depending on tariff
3. Environment Certificate costs (about 2.3c/kWh)
4. Market Charges (usually about 0.4c/kWh)
5. MLFs/DLFs – loss factors (about 6%)
6. Retailer margin – could be anything up to 15%
7. GST – 10% for now
So, even if you had 0c/kWh wholesale prices, you still have to pay those other charges as they are non-generational charges. Which is why we WILL NEVER get 1:1 FiT to match retail. The only possible scenario this could work is your retailer is also a generator/transmission/distribution company all rolled in one. But this would be a pure monopoly which I doubt would go down very well.
There are some utilities in the US where they offer NEM 1:1. There, the concept of net metering is different to ours. But even then, they are starting to move away from 1:1 (for imports:exports). Essentially a banking system, you pay for and you get back the same rate. Net metering is essentially the difference in kWh imported vs kWh exported. The net difference is what you get billed for – either in credit or in debit.
Net metering in Australia is completely different. Net metering is simply, your excess solar (what the house can’t use) exported to the grid for a nominal rate (can be either mandatory or voluntary). This is applied to your bill after the GST component has been charged to your imports, if any is used. This is the crucial bit. GST is applied to your imports before your export credit is applied. Hence, why the GST component appears to be higher than 10% than the bill total.
But with so many tiers in the Australian NEM, it’s complicated.
1) GST should not apply to household electricity consumption. How is it any different to GST on vegetables and meat etc. This would remove some of the distortion and be a progressive tax change. Pay for it with a tax on buybacks (which are a tax rort to access discounted CGT vs marginally taxed dividends).
2) Environmental credits should be paid out of consolidated revenue. Not by electricity users as it further destroys the economics of the grid.
3) Clearly we need much more storage. Stop faffing about and build a couple GW of pumped hydro NOW on a handful of the HUNDREDS of suitable sites. Just do a straight subsidy tender per MWh generated. Lowest subsidy paid for by either Government or power users wins (plus get FCAS and arbitrage revenue).
4) We need to seriously think about CCGTs place in the grid. They cannot ramp fast enough to go fully offline every day. When gas prices are > $20/GJ they have no place producing in the middle of the day. I think their time is done. Replace them with fast start reciprocating gas engines. They are almost as efficient but can fast start in as low as 2mins.
Maybe offpeak can be moved to the middle of the day as well as the middle of the night?
Or installing a way to turn on offpeak devices when electricity needs to be consumed?
I beleave heating our hot water systems when supply is in excess would be a better solution then just cutting off that extra supply and seeing it go to waste.
Thanks Michael
Have linked it into the article on WattClarity here:
https://wattclarity.com.au/articles/2022/09/11sept-minimum-demand-qld/
Paul
Will the large solar farms be shut down the same as households, as they make a far larger impact than the house solar? many of these are owned by Ergon and Energex themselves and if they shut them off in peak times it would make more sense as they don’t use power as a house does and each of these is equal to thousands of house solar systems which are still using some of the solar energy they are producing.
I don’t mind if Ergon/Energex negotiate with smart inverters (in my case Enphase) to enable this sort of functionality within existing equipment as it will allow monitoring of shut-off activities by both vendors and consumers.
To me this is more preferable than another device of which we have no visibility – it will also be faster to rollout to more installations with no hardware needing to be installed.
I understand solution proposed by government will have 100% cut-through for new/upgrading installations, however I doubt it will meet future flexibility and is likely to have it’s own security issues for state hackers now having a more uniform way to disrupt energy networks.
Negotiating with inverter suppliers is playing the long game.
Why should the authority to shut my solar system down? when I got solar power and Batteries. wouldn’t it make more sense with somebody who’s got solar power and batteries? on a sunny day. If there’s a problem with the grid, shut the grid off. because in a nice sunny day, my house is fully supported by solar and batteries. No problems.
Hi Paul,
You have a bit of a point there but what we really need to get angry about is the authorities are giving the utilities power to control stuff (which is needed) but they’re not mandating interoperability standards and software that is capable of price signalling.
You should be able to plug things in and program them to run if the price is good, not just on a dumb timer.
I wasn’t aware of this when i recently had my 10kw solar system and battery installed. If i was, i probably would have downsized my system to 9kw to stay under the threshold of 10kw here in Qld, where the emergency backstop control is required to be fitted.
Given they only let me export a peak of 5kw to the grid anyway, it would have cost me nothing to go slightly smaller. It would certainly have made sure they couldn’t turn off my solar for my own consumption, – it would have even saved me a few bucks on a couple of panels.
Be nice if solar quotes mentioned it in their guides, and installers pointed it out when quoting that is for sure!
Hi Andrew,
I’ve certainly written about GSD but I’ll see what we can do otherwise to include a warning.
Links can be found here.
Many inverter makers have re-rated their 10kW inverters to a nameplate 9.999kW just for the Queensland market so I’d be surprised the installer isn’t across that.
So it’s based on your inverter size, not your panels? I might have avoided it with my 8kw inverter then!