The Labor McGowan government announced that the emergency measure will take effect early next year as a “last resort”, to be used for short periods when solar generation sends demand for energy to low levels.
To facilitate the shut-down mechanism, 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 February 14, 2022.
The measure will not affect homes with existing solar panels and, according to state energy minister Bill Johnston, will work to allow the continued uptake of rooftop solar panels by WA households without increasing costs through the upgrading of networks.
The move by Western Australia to take overarching control of new residential solar systems connected to the SWIS follows South Australia’s move to do the same in September of last year, giving that state a deployable resource of up to 140MW of rooftop solar.
As RenewEconomy reported at the time, it has long become obvious that rooftop solar – still growing at more than 3GW a year across the country – has become Australia’s largest power station, but it has been a resource beyond the bounds of network and operator control.
For this reason, new inverter standards that will require ride-through capabilities have been expected to come into force all across the main grid, but South Australia – which just this past weekend notched up another extraordinary solar supply record – was compelled to fast-track the new rules.
And justifiably so, it would turn out, with the mechanism called into action in March of this year, when the rooftop solar systems of more than 10,000 Adelaide households were turned off at 3pm on Sunday March 14 to ride through a dangerous demand low.
Western Australia, with rooftop solar on around 30 per cent of homes and businesses on the main grid, has long been considered the state most likely to follow suit – although minister Johnston stressed on Tuesday that the state’s power stations would be turned down first, with residential solar the last to be impacted.
“Remotely switching off solar panels will be used as a last resort to prevent widespread power interruptions and is expected to occur a few times a year for a few hours,” the statement said. “This won’t affect the resident’s power supply.”
The WA government said Synergy was engaging with technology providers to simplify the process for installers and would soon be announcing the results of this process.
Johnston also noted that guidelines would be released on Thursday outlining export limits for residential systems larger than 5kW inverter capacity, so customers with higher energy consumption could install larger systems.
“This new measure means we can continue supporting the uptake of residential solar while ensuring electricity is secure and affordable,” said Johnston on Tuesday.
“The Energy Transformation Strategy is planning for a long-term future where rooftop solar, batteries and electric vehicles are at the centre of the WA power system.”
“Most homeowners worry about rising electricity bills so we create custom solar plans to ensure you never face outrageous bills ever again.”