Western Australia has joined South Australia this week to become the second state to allow the network operator to order residential rooftop solar systems to be switched off remotely as an emergency backstop to keep the grid stable.
WA on Monday brought into play its new Emergency Solar Management rules, which it has said will be used by the Australian Energy Market Operator as a tool “of last resort” over short periods on days when abundant rooftop solar generation sends demand for electricity to critically low levels.
For rooftop solar households in the state, this means that all new or upgraded solar systems (with inverter capacity 5kW and below) installed on the state’s main grid, the South West Interconnected System, will be required to have the capability to be remotely switched off, and back on again, starting from Monday.
Homes with existing solar panels are not affected by the new rules, unless their system is upgraded after February 14, 2022.
The move to exert a form of centralised control over rooftop solar on Australia’s electricity grids comes as households and businesses continue to install panels at a rate of more than 3GW a year across the country, effectively making it the largest power source in some parts of the country.
South Australia – where abundant rooftop solar generation has on occasion sent the grid to zero demand – was the first Australian state to introduce solar switch-off rules in September of 2020, calling them it into action less than six months later to ride through a dangerous demand low.
Western Australia, with its isolated grid and rooftop solar on around 30 per cent of homes and businesses, was bound to follow suit – although WA energy minister Bill Johnston has repeatedly assured that the state’s thermal power stations would be turned down first, with residential solar the last to be impacted.
“Over the past 10 years rooftop solar has increased by over 600 per cent, with 50 per cent of WA households expected to have solar panels by 2030,” Johnston said in a statement in January.
“These rapid changes to the energy landscape have presented a range of challenges and opportunities, which we are addressing to ensure electricity remains affordable and reliable.”
But at least one energy expert argues that the introduction of a solar switch-off mechanism – while “a totally reasonable ‘emergency backstop’ response to an unprecedented situation” – did not have to happen.
And he wants the occasion of its introduction in WA to serve as a hurry-along to policy makers and market bodies to pick up the pace on grid reform to a speed that matches Australia’s world-leading uptake of clean energy technologies.
“There is currently no way of diverting or storing the excess renewable energy at scale to deal with the potential risk to grid stability. Curtailing solar and wind power is the only immediate and reliable option,” said the director of the Monash Energy Institute, Professor Ariel Liebman, in a statement on Tuesday.
“This could have been avoided if Australian policy makers had not been missing in action on grid reform for more than 10 years as renewables started to grow strongly.
“We urgently need coordinated policy, and the funding of research and development. Unfortunately we can’t use international solutions on this as we are leading the charge. We therefore need homegrown innovation to address these issues.”
Liebman, in his role at Monash, has been a part of the university’s ground-breaking development of a microgrid on its Clayton campus in Melbourne, which as he explained here in 2019, addresses the challenge of coordinating distributed renewable energy sources and storage to enable an optimised flexible demand side.
His team’s efforts to minimise the curtailment of solar and wind energy at any level has also included the development of machine learning technology designed to boost the accuracy of five-minute ahead renewable energy generation forecasts.
The collaboration between Monash University’s Grid Innovation Hub, Worley and Palisade Energy, claims to have achieved a 45% improvement in customer power output predictions from wind and solar to better integrate them into the national electricity grid.
“Coal power stations tend to be more unreliable during hot weather. Solar power from household rooftop panels helps during the hottest periods such as around midday and afternoons but in the evening when it’s still hot, the unreliability of coal stations during the heat means there can still be some risks,” Liebman said this week.
“There is a need to replace ageing power stations with a more affordable, reliable and flexible combination of wind, solar and batteries.
“Optimal energy usage has been an ongoing matter for grids since they have been built. In hot countries during summer and cold during winter. Nothing new here. However, with the retirement of many ageing and uneconomic coal and gas fired plants the national grid is becoming finely balanced.”
