South Australia led the way on flexible exports for rooftop solar power systems – so what’s happening elsewhere in Australia? Here’s the state of play.
Distributed Network Service Providers (DNSPs) have export limits for solar inverters – often set at 5kW per phase. When the limit is reached, the inverter throttles output so it can’t export any higher, regardless of inverter capacity.
One of the reasons for these limits is to help reduce the risks associated with minimum grid demand events when too much solar energy is going into the grid and not enough is being consumed. Such situations can threaten network stability. Export limits also allow for more systems to be installed in a given area without expensive network upgrades.
The 5kW export limit wasn’t really an issue when the average solar system size was 6.6kW, which really wasn’t all that long ago. But systems today are bigger – 10kW and even larger is common.
There’s a better way – and that’s flexible exports done right.
South Australia A Flexible Exports Pioneer
South Australia was the first Australian state to offer flexible exports – and by and large, it appears SA Power Networks (SAPN) has done it right.
SAPN boffins developed software to forecast the network’s hosting capacity on a 5-minute basis, 24 hours in advance to help manage solar power exports of up to 10kW per inverter. When the network can handle it and a system is capable, a full 10kW can be exported. When there’s too much congestion, a signal is sent to inverters to wind output back to as little as 1.5kW until the event passes.
It’s not a case of the full 10kW export availability being very limited. SAPN modelling indicates the full 10kW is available around 98% of the time. SolarQuotes’ General Manager Trevor wasted no time in making the switch to flexible exports when it was available in his neck of the woods. You can also see details of a flexible exports curtailment event he experienced here.
The SA Government mandated flexible export capability for all new solar installations from 1 July 2023.
What About Solar Flexible Exports In Other States?
There’s more than one way to implement flexible exports – some more elegant than others. You’d think everyone else would have followed SAPN’s example given its success – but that hasn’t/may not always be the case; and that’s a problem.
Here’s the situation across the country; excluding limited trials in most cases. Much of the following information has been sourced from the Institute of Energy Economic and Financial Analysis (IEEFA).
Queensland
- Ergon and Energex have an opt-in only program using SEP2.01.
New South Wales
- In the Ausgrid area, it’s planned for FY26 using CSIP-AUS2.
- For Essential Energy, rollout is due before 2030.
- In the Endeavour region, flexible exports are planned from FY25 using CSIP-AUS and DERMS3.
Victoria
- Ausnet has an up to 5kW limit for constrained customers – and it involves proprietary technology.
- Jemena is looking to implement flexible exports from 2026.
- Powercor, Citipower and United are to all implement it over the 2026 – 2031 period.
Tasmania
- TasNetworks plans to undertake trials from this year out to 2029.
South Australia
- As of mid-November, 70% of the state (including all of the metropolitan area) can now access flexible exports. SAPN is using using CSIP-AUS.
Western Australia
- In the Western Power service area, implementation is expected by mid-2025.
- In Horizon Power’s region, it’s available with *no* export limit. It requires a secure gateway device; provided by Horizon free of charge.
Northern Territory/ACT
- I wasn’t able to determine what’s in the pipeline; although EVO Energy (ACT) says it will introduce flexible exports at some point – just not when.
IEEFA Weighs In On Flexible Exports
The IEEFA says all Australian energy customers could have their electricity costs reduced if flexible exports for rooftop solar power were enabled across the nation, as cheap solar energy pushes wholesale prices down.
But IEEFA guest contributor Dr Gabrielle Kuiper says given flexible exports are not being rolled out consistently or quickly, this is creating additional costs for inverter and gateway manufacturers, and unnecessarily increasing the cost to solar consumers.
“The implementation across six jurisdictions by 11 different distribution network service providers (DNSPs) is being planned or delivered using a variety of standards and devices,” Dr Kuiper says. “Unless there is a nationally consistent approach to communication and integration, meeting all requirements for all DNSPs will be a huge undertaking by industry.”
The IEEFA estimates delays to implementation cost households installing new solar systems and those with existing 8-15kW solar systems a combined A$35 million in 2023, through lost feed-in tariffs.
“This cost will accumulate to A$211 million over the next three years, and will grow further if the implementation of flexible exports is delayed beyond 2026,” the organisation says.
While FiTs aren’t as generous as they once were and maximising solar energy self-consumption is the name of the game, every little bit helps.
To minimise the cost of compliance to inverter manufacturers, Dr. Kuiper says basic common requirements could be put in place, and has urged the powers-that-be to lodge a rule change to look at options to not only fast-track flexible exports, but also to manage minimum system load. This includes ‘emergency backstop’ mechanisms; a different beast to flexible exports – but the latter can help avoid use of the former.
You can read more about how rapid implementation of flexible exports could maximise rooftop solar in a new analysis from the IEEFA.
Footnotes
- Smart Energy Profile 2.0 (SEP2) was created ZigBee Alliance with support from HomePlug Alliance as an energy management standard. ↩
- CSIP-AUS is a standard enabling smart inverters and energy management systems to work with dynamic/flexible connection options. ↩
- Distributed Energy Resource Management System (DERMS) developed by Mondo ↩
SEP2.0 I think is where the meter is Zigbee enabled. As far as I know, SA & Vic have Zigbee enabled meters, but I know NSW does not.
Why cant all the areas standardise the control & metering? This would allow consumers to view/use the immediate data from their own meter. This is by interfacing to a Home Management system (such as Home Assistant), or simply having a display where they can see real time data.