South Australia has been a leader in flexible rooftop solar exports – so what’s happening elsewhere in Australia? Here is the state of affairs.
Distributed Network Service Providers (DNSPs) have export limits for solar inverters – often set at 5 kW per phase. When the limit is reached, the inverter throttles the power so that higher power can no longer be generated, regardless of the inverter capacity.
One of the reasons for these limits is to help reduce the risks associated with minimal grid demand events, when too much solar energy is exported to the grid and not enough is consumed. Such situations can jeopardize network stability. Export restrictions also allow additional systems to be installed in a specific area without expensive network upgrades.
The 5kW export limit wasn’t really a problem when the average solar system size was 6.6kW, which wasn’t all that long ago. However, today the systems are larger – 10 kW and even more are common.
There is a better way – and that is flexible exports done right.
South Australia is a pioneer in flexible exports
South Australia was the first Australian state to offer flexible exports – and on the whole it appears SA Power Networks (SAPN) got it right.
SAPN boffins has developed software that predicts network hosting capacity on a 5-minute basis and 24 hours in advance to help manage solar energy exports of up to 10 kW per inverter. If the network can handle it and a system is capable, a full 10kW can be exported. If there is too much congestion, a signal is sent to the inverters to reduce wind power to just 1.5 kW until the event passes.
It’s not that full 10kW export availability is very limited. SAPN modeling shows that the full 10kW is available approximately 98% of the time. Trevor, General Manager of SolarQuotes, wasted no time in switching to flexible exports when they became available in his area. Here you can also see details of a flexible export cut he experienced.
The South African government has mandated flexible exportability for all new solar systems from July 1, 2023.
What about exports of flexible solar energy to other countries?
There is more than one way to implement flexible exports – some are more elegant than others. Given its success, you might think that everyone else would have followed SAPN’s lead – but that hasn’t always been, or may not always be, the case. and that is a problem.
Here is the situation across the country; In most cases, limited trials are out of the question. Much of the following information comes from the Institute of Energy Economic and Financial Analysis (IEEFA).
Queensland
- Ergon and Energex have an opt-in-only program with SEP2.01.
New South Wales
- In the off-grid area, the use of CSIP-AUS2 is planned for the 2020 financial year.
- Essential Energy is scheduled to launch before 2030.
- In the Endeavor region, flexible exports with CSIP-AUS and DERMS3 are planned from FY25.
Victoria
- Ausnet has a limit of up to 5kW for restricted customers – and it is proprietary technology.
- Jemena wants to implement flexible exports from 2026.
- Powercor, Citipower and United will all implement it in the period 2026 – 2031.
Tasmania
- TasNetworks plans to conduct trials from this year to 2029.
South Australia
- As of mid-November, 70% of the state (including the entire metropolitan area) can now access flexible exports. SAPN uses CSIP-AUS.
Western Australia
- In the Western Power supply area, implementation is expected by mid-2025.
- In Horizon Power’s region it is available without export restrictions. It requires a secure gateway device; provided free of charge by Horizon.
Northern Territory/ACT
- I haven’t been 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 comments on flexible exports
The IEEFA says all Australian energy customers could reduce their electricity costs by allowing flexible exports of rooftop solar power across the country, as cheap solar energy pushes down wholesale prices.
But IEEFA guest author Dr. Gabrielle Kuiper says the failure to roll out flexible exports consistently and quickly creates additional costs for inverter and gateway manufacturers and unnecessarily increases costs for solar customers.
“Implementation in six jurisdictions by 11 different Distribution Network Service Providers (DNSPs) is being planned or carried out using different standards and devices,” says Dr. Kuiper. “Until there is a uniform approach to communications and integration across the country, meeting all requirements for all DNSPs will be a huge undertaking for the industry.”
The IEEFA estimates that implementation delays will cost households installing new solar systems and households with existing 8-15 kW solar systems a total of A$35 million in 2023 due to lost feed-in tariffs.
“These costs will amount to A$211 million over the next three years and will rise further if the introduction of flexible exports is delayed beyond 2026,” the organization says.
Although feed-in tariffs are no longer as generous as they once were and maximizing your own solar energy consumption is the name of the game, every little bit helps.
To minimize compliance costs for inverter manufacturers, Dr. Kuiper will introduce basic common requirements, and he has called on future rulers to submit a rule change to explore options to not only accelerate flexible exports, but also to manage minimal system load. These include “emergency backstop” mechanisms; a different beast than flexible exports – but the latter can help avoid using the former.
You can read more about how rapid implementation of flexible exports could maximize rooftop solar energy in a new analysis from IEEFA.
Footnotes
- Smart Energy Profile 2.0 (SEP2) was created as an energy management standard by the ZigBee Alliance with support from the HomePlug Alliance. ↩
- CSIP-AUS is a standard that enables smart inverters and energy management systems to work with dynamic/flexible connection options. ↩
- Distributed Energy Resource Management System (DERMS) developed by Mondo. ↩
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