Australia’s largest electricity grid operator has called for emergency powers to manage rooftop solar energy generation.
The Australian Energy Market Operator wants to implement emergency backstop measures for rooftop solar, allowing solar generation to be reduced or turned off in exceptional circumstances.
When more solar power is exported to the grid than can be used, issues in electricity supply instability, voltage problems and power outages can occur.
AEMO executive general manager for operations Michael Gatt said the company did not want to directly control people’s rooftop solar.
“We’re aware that high contributions of rooftop solar coinciding with certain system conditions needs to be carefully managed to ensure electricity reliability and grid security while managing power system risks,” Mr Gatt said.
Action to secure the grid can be taken by AEMO in some instances, especially emergency events, which often coincide with unplanned outages, Mr Gatt said.
After all available actions have been exhausted, temporary management of rooftop solar by network operators could be required.
“We expect this may only occur in very rare circumstances,” Mr Gatt said.
“These actions assist in keeping the power system secure, while also enabling the growth of rooftop solar installations.”
Victoria already has emergency backstop powers in place, with small and medium solar systems newly installed or upgraded able to be managed since October this year.
According to the Department of Energy, Environment and Climate Action, the backstop occasionally needs to be used on mild, sunny days when there is low demand for electricity.
However, AEMO’s Supporting secure operation with high levels of distributed resources report released this month said emergency backstop measures in Victoria may no longer be adequate by next year as their capabilities were small.
It recommends implementing monitoring and enforcement measures to increase compliance in all regions, given the projected continued growth in rooftop solar.
Electricity generated by rooftop solar panels can, during sunny periods, create enough power to meet half of total demand across the National Electricity Market.
One in three households have rooftop solar, and expected future uptake could occasionally supply 90 to 100 per cent of the grid’s energy needs, the report said.
Minimum operational demand, meaning the lowest levels of energy required from the grid, has decreased in recent years, largely due to rooftop solar output.
When more solar energy is exported to the grid than can be handled, minimum operational demand is threatened as other sources of electricity are reduced to secure the grid.
More traditional forms of energy, such as coal and gas, generate electricity through spinning turbines used to harness the resources.
As the turbines rotate, they produce a large mass of energy, which provides consistent power to the grid.
If rotating inertia is lost, such as when turbines are slowed down to reduce electricity generation when accommodating solar energy spikes, they could stop entirely and are difficult to restore quickly.
Solar and other renewable resources do not provide the same level of consistent power generation due to their characteristics.
State Member for Murray Plains Peter Walsh said Victoria’s infrastructure was inadequate to handle the excess electricity generated by rooftop solar.
“As summer heats up, rooftop electricity production soars, and there is now nowhere for it to go,” Mr Walsh said.
“It’s either shut down the rooftop industry or shut down the power stations. When that happens, it will be a disaster because you can’t just switch those back on.”
AEMO’s report said it was committed to delivering power system security as energy generation changed towards more renewable resources.
Reducing minimum operating levels of traditional energy sources, and investment in new assets, such as batteries, could allow the grid to work securely during lower levels of operational demand, the report said.