The push for strict and uniform solar inverter standards that will allow rooftop PV systems to be controlled and switched off remotely has gained new muscle this week, with the Clean Energy Regulator adding checks of inverter settings to its inspection program.
The CER said on Tuesday that it was working with the Australian Energy Market Operator and the Clean Energy Council to incorporate the inverter checks as part of its duties under the Small-scale Renewable Energy Scheme.
The new inspection program will be checking for compliance of inverter configurations with the Australian Standard 4777.2-2015, as well as compliance of inverter configurations with the requirements of each PV system’s corresponding distribution network service provider.
According to the Clean Energy Council, AS4777.2-2015 – updated in 2015 and in effect since October 2016 – includes requirements such as reactive power capability, new voltage and frequency set-points and limits to be compatible with requirements of network businesses.
The updated standard also requires inverters to have Demand Response Mode (DRM) capabilities, which gives a remote operator the ability to perform tasks like disconnecting the inverter from the grid, preventing the generation of power, or increasing power generation.
The standard also gives distributed energy resources the capability to provide services to the network, such as provide stored rooftop solar power at times of peak energy demand by way of coordinated virtual power plants – a resource AEMO believes will be crucial to Australia’s energy supply in the not-too-distant future.
Notably, the national standard does not yet require inverters have the ability to “ride through” system faults – a capability the AEMO is seeking to make compulsory to prevent large amounts of rooftop solar suddenly disconnecting as a result of voltage disturbances.
That said, a Short Duration Undervoltage Disturbance Ride-Through (VDRT) Test Procedure developed by AEMO to ensure inverters responded appropriately during short-duration voltage disturbance events found the majority – 10 out of 17 – of commonly installed inverters developed against AS/NZS 4777.2:2015, already had this capability.
South Australia – whose grid saw solar supply reach up to 93.7 per cent of state demand on the weekend – has decided to take matters into its own hands on this front, with strict statewide inverter standards to be introduced later this month under the government’s “Smarter Homes” program.
As RenewEconomy has reported, the rushed new standards which will apply to any new rooftop solar installation contract signed after August 10 has been met with concern from the two peak solar bodies, who report industry “chaos and confusion” and fears that installers will be left holding crippling amounts of unusable stock.
The CER – which already conducts comprehensive testing of the overall quality and safety of installed rooftop solar systems – said collecting the inverter data would help inform Australian standards development and could be used by AEMO, the CEC, Distribution Network Service Providers (DNSPs), or state and territory regulators to monitor compliance.
“Australia now has over 2.5 million grid-connected small-scale solar PV systems, with approximately 310,000 (representing 2.4 GW) installed in 2019. Together these individual systems amount to one of the biggest generators in the electricity grid,” the CER said.
“Small-scale solar PV systems that comply with Australian standards and DNSP requirements improve the reliability of the grid and allow more systems to be connected in the future. This will ensure the rooftop solar industry can continue to thrive.”