With more than four million solar systems now installed on Australian rooftops, the Australian Energy Market Operator (AEMO) is calling for stronger measures to manage the surge in rooftop solar power, which is pushing the national electricity grid to its limits.
South Australia, Victoria, Queensland, and New South Wales could face blackouts as the “solar tsunami” tests grid stability, AEMO warned in a report released on Monday.
“The emergency periods where this kind of intervention is required should remain infrequent, but essential for maintaining a secure and reliable supply of electricity for customers,” AEMO said.
The core issue stems from what energy experts call “minimum demand”- periods when rooftop solar generates so much power that traditional generators are pushed to the margins.
In South Australia, solar output has periodically exceeded 100 per cent of the state’s electricity needs, with surplus power exported to other states.
AEMO is proposing an “emergency backstop” mechanism that would allow network operators to reduce or temporarily switch off rooftop solar systems in extreme circumstances. Similar powers already exist in some states, but AEMO wants them extended nationwide by next year.
The potential risks are significant. Without intervention, AEMO warns the grid could operate “insecurely” for extended periods, potentially compromising the ability to restore power after a major outage.
Spring presents the most acute challenge, with longer, sunnier days coinciding with lower electricity demand as mild temperatures reduce air conditioning use. AEMO predicts rooftop solar could meet up to 90 per cent of system demand in the coming years.
“(It may) therefore be operating outside of the risk tolerances specified in the National Electricity Rules, where the loss of a single transmission or generation element may lead to reliance on emergency control schemes to prevent system collapse.”
According to AEMO, the proposed measures do not mean it intends to directly control individual solar installations. Instead, the focus is on maintaining grid stability during periods of extreme solar generation.
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