South Australia’s rooftop solar could be switched off on the way to 100% renewables


In response to a new report from the Australian Energy Market Operator (AEMO), the South Australian government has released a detailed plan designed to protect its electricity network from a possible state-wide blackout as it moves towards its 100% renewables goal by 2030. The plan aims to accelerate a range of reforms to better integrate distributed energy resources into the energy system and address the rapid uptake of rooftop PV over the last decade that has outstripped regulations.

According to the SA government, the report has identified “the very real threat of another system black unless short, medium and long term improvements to the system are implemented”. To address this, SA has given the green light to AEMO to manage the output of its rooftop PV fleet when needed and provided the market operator with “a necessary backstop in times of emergency”.

The move is yet another confirmation of the urgent need to change regulatory frameworks in Australia in order to adapt to the evolving power system. This is particularly important with regard to frameworks for sourcing essential system services and technical standards applying to the growing fleet of rooftop PV, distributed batteries and EVs on the grid.

“The State Government will also introduce new smart solar standards in South Australia, ahead of national changes, to ensure that new solar supports the grid during disturbances and can be managed like any other generator when needed to support energy security,” Minister for Energy and Mining Dan van Holst Pellekaan said on Friday. This will most likely involve new standards for inverter settings to maximize the potential contribution of solar PV.

On the federal level, in collaboration with industry, through the Standards Australia committee, AEMO is seeking to progress update to the national standard for inverters (AS/NZS4777.2) to incorporate bulk system disturbance withstand and autonomous grid support capability by 2025. However, it appears that the federal regulatory reforms are too slow for SA, which is leading the country in the uptake of rooftop PV and wind energy.

Voltage management and new line

Under the new plan, the SA state government is also providing $10 million to South Australia Power Networks to upgrade its voltage management. This is aimed to help prevent potential voltage disturbances near Adelaide identified in the new AEMO analysis that could see up to 400 MW of rooftop solar simultaneously disconnected. “Bringing forward this investment will allow South Australia to securely host more rooftop solar and improve the quality of power received at people’s houses,” the minister said.

The need for network improvements in SA is nothing new with the risk highlighted following a state-wide blackout in 2016. Referring to the new AEMO modeling, the state government says that such actions would be a step in-between “to manage low demand conditions due to a decade of unmanaged rooftop solar uptake.” However, the “single most important finding of AEMO’s report is that the SA-NSW interconnector is critical to the long-term security of South Australia’s electricity system,” Van Holst Pellekaan underlines.

“The delivery of the 800 MW Project EnergyConnect will enable the continued growth of household solar installations whilst driving down the price of power and keeping the entire electricity system stable,” he said.

The 900-kilometer transmission line built by ElectraNet and Transgrid, which got a regulatory go-ahead from the Australian Energy Regulator in January, is set to enhance power system security and allow for further development and integration of large-scale renewables into the nation’s main grid. It will also unlock up to 30 new wind and solar projects totaling nearly 5.3 GW planned for South Australia, New South Wales, and Victoria.

Labeled as a critical part of the national transmission plan, which AEMO has declared a “no regrets” measure, the Project EnergyConnect will boost security and cut prices. “Fortunately, we are already underwriting early works to accelerate the project as fast as possible,” the minister said. However, until the new line is delivered, actions in cooperation with AEMO, SA Power Network, ElectraNet and ESCOSA will be taken to address the risks to the SA grid. Without these actions, a moratorium of new solar would be required, AEMO has said.

Congrats and concerns

The Clean Energy Council (CEC) has welcomed the South Australian Government’s “firm plan for getting to 100% renewable energy”. In response to AEMO’s new modeling, Australia’s peak body for the clean energy industry has once again underlined the need for stronger network interconnections and a new way to operate an increasingly distributed grid.

“The project has been burdened by a regulatory process and RIT-T that is no longer fit for purpose,” said CEC Chief Executive, Kane Thornton. “Accelerating Project EnergyConnect is key to addressing the challenges identified in the AEMO report, as is continued investment in energy storage at the household, community and utility-scale.”

It also commended the plan for recognizing the importance of leveraging smart technology built into solar power systems, which can be achieved by updating regulations and standards to catch up with the latest technology developments. “We need to change the way that we manage solar and battery systems and how they interact with the grid,” said Thornton. “New rules are required to mandate technological capability and new markets to make the best use of the capabilities already at our disposal.”

NGO Solar Citizens congratulated the SA Government on its commitment to achieving 100% renewable energy by 2030 but also expressed concerns that a rule change to allow rooftop solar curtailment could be exploited. “It’s wonderful to see that both the South Australian Government and AEMO are working to enable the growth of rooftop solar,” said Stephanie Gray, Campaigner at Solar Citizens. “But we need to ensure that rooftop solar curtailment is a last resort that only occurs in emergency situations.”

“Households across the country have made the solar switch to slash their electricity bills and do their bit for the environment. They should not be unfairly penalised for making an investment that provides cheap electricity to the grid,” she said. “It’s vital that the State Government and network continue to explore and implement other options, such as battery storage and demand response, to overcome grid issues.”

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