South Australia’s electricity distributor SA Power Networks (SAPN) has announced it will be introducing an export tariff —sometimes incorrectly referred to as a ‘sun tax’ — from July 1 this year. Here’s why, how it will work and how much it will cost.
SAPN has been grappling with managing increased solar energy goodness flooding South Australia’s grid during the day — a grid that was originally designed to deliver energy one way; from the generator to consumer. Too much of this particular good thing can threaten electricity network stability and equipment.
Among the actions SAPN has taken to date are the introduction of inverter limits, remote disconnect/reconnect and pioneering flexible solar exports. But it seems that won’t be enough.
SAPN says to ensure South Australians can keep exporting electricity from their solar panels into the future, it needs to carry out targeted network upgrades and intends investing approximately $82 million on related projects and services between this year and out to 2030. Some of the work includes upgrade of voltage control at SAPN substations and the installation of new street transformers.
“These upgrades will benefit every customer in the State over time, even those without solar — but those with solar will see greater and more immediate benefits. This investment will be enabled through an export tariff,” states SAPN. “It means that electricity network upgrades to support these energy exports are funded by those who benefit from them the most. This makes it fairer for those who do not have the ability to export energy.”
How SAPN’s Solar Export Tariff Will Work
The export tariff will be a charge applied to surplus energy exports only, and only above a ‘free’ threshold at certain times. It will:
- be introduced from 1 July 2025;
- charged to electricity retailers, who will decide if/how they pass on this charge; e.g. as a feed-in tariff reduction;
- apply to all residential and small business customers who export through solar PV, batteries and V2G connection with an inverter capacity up to 30kW AC;
- also apply to flexible export customers;
- not apply to the first 9 kilowatt-hours (kWh) exported to the grid per day between 10am – 4pm for customers with an interval (smart) meter;
- not apply to the first 11 kWh exported per day between 10am – 4pm for customers with an accumulation meter; and
- not apply to exported electricity outside of 10am – 4pm each day.
If a residential customer doesn’t use all their daily free export, it can be used on another day within the billing cycle (typically 90 days). For small business customers, there’s a rollover feature as well, but their billing cycles are usually shorter (30 to 31 days). Furthermore, unused daily free export from businesses on a ‘work day’ can only be used on another work day, while unused daily free export from a ‘non-work day’ can only be used on another non-work day.
How Much Will The SA Export Tariff Cost?
Electricity retailers will be charged 1c per kWh for exports from customers with interval meters and .75c per kWh for customers with accumulation meters; above the free daily thresholds between 10am – 4pm.
SAPN says if a retailer passes on the tariff in full, for the average household (5 kW inverter and medium self-usage/exports) it will cost approximately $1.50 per month. For the average small business (based on a 15 kW inverter with medium self-consumption/exports), it will cost approximately $6.00 per month.
SolarQuotes’ Ronald Brakels crunched some numbers relating to households with a smart meter, and here’s what he came up with.
“For 6.6kW of north-facing solar on a home with typical electricity consumption, it will come to an average of around 0.5c per kWh exported in January – the highest output month. In June, it should basically be nothing. Very roughly, in this case, it will average around 0.3c per kWh exported.
For larger systems, e.g. 20kW, 30kW, it will get closer to 1c per kWh exported, but never actually reach it.
The result of the export tariff should be a small drop in solar feed-in tariffs offered by electricity retailers, but the export tariff will also contribute to more annoying solar system size restrictions on electricity plans.”
A Little Carrot With The Stick – For Some
SAPN mentions some customers may also get a credit above standard feed-in tariff rates if they export energy at times when other customers need it most.
“If you are on SA Power Networks’ customer choice Electrify tariff, from November till March, SA Power Networks will pay your retailer a credit of 12-13 cents per kWh for energy exported between 5pm and 9pm. You will need to contact your retailer to find out whether you are able to access this tariff.”
I believe this refers to SAPN’s “Residential Electrify” trial tariff — or something similar — mentioned here and here. It features stronger pricing signals than the default residential Time of Use (ToU) tariff.
Minimising The Impact
Maximising solar energy self-consumption through actions such as setting an electric hot water system on a timer has been the name of the game for years, and now even more so with the introduction of export tariffs.
But there’s only so much households can self-consume, especially if no-one’s home during the 10am – 4pm window. While the cost impact should be minimal regardless, the introduction of export tariffs in South Australia might also provide a little extra motivation for some to consider a home battery — particularly given the federal battery rebate official launch is less than three weeks away.
“Installing a battery will reduce the amount of export tariff paid, as it reduces exports,” says Ronald. “If people are desperate to reduce their export tariff amount, they could set their battery to only start charging at 10am. But I would not advise this for most households, as they would probably end up worse off by missing out on a little battery charging.”
For those considering installing solar panels, he added:
“Having east/west facing panels will help reduce the amount of export tariff, partially due to lower overall output compared to north facing panels, but also because they produce more outside of 10am-4pm and because these homes have higher self-consumption.”
Further information is available on the SAPN export tariff explainer page.
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How does a spinning disk meter know what time energy was exported? Is it imputed? I didn’t realise it could even measure exports.
Is it likely very many people in SA have solar, but an accumulation meter?
I wonder what the logic is for going harder on interval meters?
Hi Glen,
Spinning disks go backwards when powered by solar exports. The novelty never wears off but technically it’s electricity theft.
However solar can be installed on a digital accumulation meter, for a decade(?) SAPN installed dumb meters for solar which had a more accurate clock for off peak but no remote/ripple control.
Internet connected meters offer time-of-use possibilities, through many retail plans stay with simple block pricing.
What is theft again ? p3 refers.
https://links.sgx.com/FileOpen/(Signed)%20SA%20Power%20Networks%20-%2031%20Dec%202023%20Accounts.ashx?App=Prospectus&FileID=62552
*Checks current inverter data*
Okay so it’s only the middle of the 10am to 4pm period and I’ve exported about 20 kWh. Assuming the same sort of reduction over time as yesterday, that’s another dozen or so kilowatt hours that will be generated.
At 1c/kWh on a 10c/kWh FiT that’s a 10% Sun Tax – basically GST.
At 1c/kWh on a 5c/kWh FiT that’s a 20% Sun Tax – twice GST
At 1c/kWh on a 4c/kWh FiT that’s a 25% Sun Tax
And if your FiT is less than that you probably need a new electricity plan – sorry WA.
While SAPN figures say the average household will pay $1.50/month, is that including non-solar households? At 20 kWh exported per day that’s about $6/month, but you can roughly double that figure for summer!
I’m not sure why my figures vary so much from Ronald Brakels’ other than he’s assuming a small system. Do others here note a discrepancy (whether in SA or not)?
The first 9kWh are ‘tax’ free.
So are the before 10 am and after 4 pm exports.
The 9kW allowance carries over on rainy days.
The average export rate is for all exports, not just the 10-4 exports on a good day.
For a bigger system, the 9kWh allowance is a smaller proportion of the total exports, which results in a higher average export ‘tax’ rate.
If you can export 40kWh in 3 hours in Summer, you must have a bigger system. Here’s some calcs for a 10kW system.
https://www.sapowernetworks.com.au/public/download.jsp?id=332876
Thanks Glen
Yes I got the first 9kWh per day was free, hence why I didn’t include the 12 kWh I was predicting would be generated after my post.
If I’m reading your SAPN graph right then June 2023 exports are about 380 kWh, mostly comprise of the 10am to 4pm free 9kWh/day (270 kWh). By contrast my own exports for June 2023 were 958 kWh, 888 kWh in June 2024, and likely ~865 kWh June 2025. That’s over double SAPN’s premise! Something under $6 per month, but not the SAPN 50c or so.
For October 2023 SAPN figures are about 1,450 kWh. My exports were 1,644 October 2023 and 1,478 October 2024 which actually is similar. I’d absolutely not be looking at the $18/year sun tax SAPN suggest is the average household, but rather $80+/year, potentially closer to the $120 mark, which is above even SAPN’s average small business estimate. The group the sun tax truly targets is the high generation low consumption crowd, those like myself. If your solar investment isn’t paid off yet …
So exporters of PV electricity are to be charged a fee for their surplus over 9kwh between the 10 to 4 window, and they are also curtailed when the grid is full so there is no problem to solve, hardly makes sense!!!
But how are they rewarded for producing surpluses when its hot and everyone comes home to put on their air conditioners in summer,,,, and SAPN has not needed to do upgrades to carry the extra load as more people get air conditioners and electrify their homes from gas, only because these same panels are fulfilling the extra need locally?
I think you missed this bit in the article:
“If you are on SA Power Networks’ customer choice Electrify tariff, from November till March, SA Power Networks will pay your retailer a credit of 12-13 cents per kWh for energy exported between 5pm and 9pm. You will need to contact your retailer to find out whether you are able to access this tariff.”
You’ll probably need to be with Amber Electricity for this to be passed on to you. It will be interesting to see if that will be sufficient to make energy arbitrage economic. That is, discharging batteries into the evening peak and buying a bit back in the very early morning to carry through until the solar system starts generating again.
If this was really about feedback, we’d be given more than 1,000 characters to respond. Here’s what Australians are dealing with:
Some of the highest electricity prices in the world
$400+ annual supply charges just to be connected
Feed-in tariffs slashed to near zero
Usage rates creeping toward 50c/kWh
Now, a new charge just to export solar — which the grid then resells at profit
Solar system costs of $20k–$35k with shrinking returns
Government “subsidies” funded by taxpayers = another hidden cost
We were promised savings and fairness. Instead, the rules keep changing, always against us. This “sun tax” feels like a betrayal. People are right to be angry — they’ve done the right thing, suddenly they’re a “tightarse” for not wanting an expensive battery system?
We saw it happening in Germany, we know the playbook. This is coercion, it’s not fair, equitable, or a public service. Lump it or leave it, and a healthy dose of condescension.
Destination: PEAK SOLAR
Kids in the back seat are asking: “Are we there yet?”
A: “nearly there! – just gotta wait till all us suckers have doled out another 10 grand for batteries!”
‘Some of the highest electricity prices in the world…’ It depends where you live.
Australia’s electricity is more expensive than the global average, but not the world’s most expensive. Within the OECD, Australia’s residential power costs are slightly below average, indicating reasonable affordability compared to peer nations.
However, Australians pay significantly more than many low‑cost regions and heavily compared to developing countries.
Price variation within Australia is significant—from about 19 ¢/kWh in SE Queensland to over 34 ¢/kWh in South Australia.
A comparison with the UK:
Australia’s residential electricity is significantly cheaper than the UK’s. On a per kWh basis, Australians pay about 25–35% less for electricity.
The UK’s price cap mechanism limits costs but still results in higher unit rates and daily standing charges, reflecting the cost structure and regulatory framework in the UK.
AGL email 3 days ago with new rates from July 1, SA metro.
Peak tariff up nearly 14% to just over 56c.
Supply charge up nearly 14%.
FIT down from 4c to 2c.
Sun tax penalty starting too, but won’t have a huge affect until after winter.
Battery now essential in SA for anyone getting solar, or this with solar wanting to be in any sort of control of electricity costa.
Newbie question so please be gentle.
I’m about to sign a contract for a new system; 17.4 kw of Aiko panels, Sungrow 10kw hybrid inverter and 16kwh Battery.
Obviously I will be self-consuming as much as possible but is there a way to automatically limit my inverter to avoid paying this tariff?
If my Sungrow inverter settings can manage this. would any “add-ons” like Charge HQ, Catch Power or Solar Analytics handle this?
thanks
Hi Stephen,
There’s certainly ways to do it but it depends if you want to use something smart, like a wholesale tariff like Amber with their inverter integration, or maybe a CatchControl will do it?
The dumb way is just an export limit but that curtails potential for feed in tariff earnings depending on how you tune it, and if things change seasonally.
Your installer should be able to advise.
Presumably the inverter via the app turn FiT off.
Solar Panel Drone Inspections are a game-changer for solar maintenance! They offer a safer, faster, and more accurate way to detect issues like hotspots, cracks, or dirt buildup. Using thermal imaging and aerial views helps reduce downtime and optimize energy output. We’ve seen great results on large-scale solar farms—definitely worth the investment. Curious how often others schedule their inspections?
Isn’t the easy answer just to set your inverter to not export any solar power above your “free” limit?
I don’t get why this solar soak penalty is even needed.
SAPN can curtail now whenever needed, in fact they curtail big solar and wind first, then large commercial rooftop PV, and lastly residential rooftop PV.
Why do they even need this ?
It might have the effect of people setting their systems up to only look after their own needs, no exporting, and that seems to defeat the renewables concept.
SAPN need to modernise the distribution network. Up rate feeders and transformers to handle the bidirectional nature of energy flow in a modern electricity network hitherto unidirectional.
Both the Australian Energy Regulator and SAPN have determined that you the prosumer have to pay for this upgrade while SAPN’s Hong Kong owners get a return of 25% pa regardless. The ‘poles and wires’ are a natural monopoly so there is nowhere else to go.
The only real alternative is to go off grid with a suitable amount of panels/inverter/ storage which nominally will cost you $A 30k – 40k
https://www.aer.gov.au/system/files/2025-05/AER%20-%20Statement%20of%20Reasons%20-%20SA%20Power%20Networks%20-%202025%E2%80%9326%20Pricing%20Proposal.pdf
I like this policy (btw, I have solar and a battery in SA).
It will discourage exports during the day when we have excess solar.
With rising import tariffs it will make batteries, larger batteries, more economic.
It will reward people with west facing panels who export in summer, reducing peak wholesale prices.
It will encourage me (or rather the Amber electricity algorithm) to consider discharging my battery into the evening peak in summer and buy some back in the early morning.
It will encourage people to self-consume during the day.
All this will work to suppress electricity price rises, benefiting the poorest people, those renting without solar.
If you still have gas hot water, install a heat pump heater now and set it to run during the day. Payback time will be around 2 years.
I’ve recently had dealings with Ausnet in Vic, installing solar on a home unit. Give me a Chinese owned DSPN (SAPN) over a US private equity one (Ausnet) anyday. Much easier process here. Bravo SAPN.
Do the same rules (or other rules) also apply to large scale wind and solar at over production times?
I haven’t had any word from AGL here in SA yet re this solar soak penalty, and how / if it will be applied separately or whatever.
As per my post above, the FIT is reducing from 4c to 2c come July 1 too, so maybe the is absorbing the ‘sun tax’ within that ?
Trouble (for the consumer) is that would see AGL reaping extra profits from FITS up to 9kWh threshold in the 6 hour daytime block (proposed 1000 – 1600), and outside those solar soak hours.
Interestingly this 6 hours is longer than their normal shoulder TOU of 1000 – 1500, so they are already joining the morning peak 0600 – 1000 and afternoon peak 1500 – 1159).
I’ll be looking around at options come July 1st, been with AGL for total 67 years combined with home (42 years) and workshop (25 years).
Jon from SA
As usual the monopoly SAPN gets away with anything it wants. I worked for them once and it was a business totally focussed on delivering $ to it’s Hong Kong owner. We have a 50 year old pole mounted wooden cross- arm with distribution switches and it also supplies our house. It is totally rotted out and will probably fall down like the one across the street taking out the area after hours.
So much for what is required and where it’s spent.
Time to stop exports……
Even worse in the switch yards. existing infrastructure has no records of past work, so makes it very costly and dangerous to upgrade or modify. for example radio towers had no records of what antennae were there or the loading on the arms carrying them. The whole lot had to be digitally photographed and brought into CAD and measured to see if you could safely augment them. Not a bad ide actually.
Reason ? Infrastructure has been run down over x years to make it profitable for sale so Mr HK gets his 25% pa regardless.
Destination: PEAK SOLAR
Kids in the back seat are asking: “Are we there yet?”
A: “nearly there! – just gotta wait till all us suckers have doled out another 10 grand for batteries!”
I’m on SAPN tariff RELE2W in conjunction with Amber Electric.
I “pay” the 1c / kWh all year round from 10.00 to 16.00.
In Nov – March, I am paid 12.36c /kWh for any export between 17.00 and 21.00.
What Amber shows me is the wholesale prices at my location after taking these adjustments into account.
I still make money during the day (sometimes) despite the 1c charge.
FWIW, Amber “Smartshift” seems to have improved it’s decision making recently after the introduction of doing 5 minute pricing properly. Now if only they could react to manual interventions and “minimum Reserve levels” in a timely manner to take advantage we’d be cooking on electricity as it were.
My new electricity price from Origin has a -$.04 feed in tariff.
Goodbye and good riddance Origin.
If my energy retailer passes this cost into me I will be turning off exporting to the grid altogether. I encourage everyone to contact their solar installer and ask them to turn off exporting to the grid.