Australia's electricity grid operator wants the power to remotely switch off or constrain the output of new rooftop solar systems, as it finds ways to manage South Australia's world-leading levels of "invisible and uncontrolled" solar output.
The recommendation is contained in a new report by the Australian Energy Market Operator, which sets out how it will manage the grid up to 2025.
At times, as much as 75 per cent of Australia's energy is forecast to be provided by wind and solar.
The report shows at certain points last year, 64 per cent of South Australia's power demand was met by rooftop solar alone.
AEMO's forecasts show that figure could grow as high 85 per cent by 2025, with rooftop solar also tipped to dominate supply at times in in Victoria (up to 66 per cent), Queensland (57 per cent) and New South Wales (48 per cent).
But the runaway success of solar power poses serious challenges for the security of the grid, because it operates "behind-the-meter", out of control of the authorities.
To manage the growth, AEMO is looking to impose requirements on new solar systems in South Australia to enable "generation-shedding capabilities" as soon as possible.
Other states and territories will be encouraged to adopt a similar approach.
While the use of batteries might help the market operator avoid powering down household rooftop systems, it describes the ability to remotely control panels as an essential "back-stop".
AEMO's managing director Audrey Ziebelman says the study makes clear that the current approaches used to manage the electricity market are becoming less effective as the grid continues its transformation to world-leading levels of renewable generation.
"Australia already has the technical capability to safely operate a power system where three quarters of our energy at times comes from wind and solar energy generation," Ms Ziebelman said.
"However, to do so requires changes in our markets and regulatory requirements, otherwise, AEMO will be required to limit the contribution of these wind and solar resources to 50 or 60 per cent of electricity supply at any point in time, even though they are the lowest cost way of providing electricity."
