The South Australia state government has announced the first batch of approved inverter suppliers and agents that will ensure that new rooftop solar installations have the ability to “ride through” system faults, can be subject to changing export limits and can be disconnect from the grid if needed.
The strict new standards – imposed under the government’s “Smarter Homes” program – are in response to the growing share of rooftop solar in the state’s generation mix, and fears from the Australian Energy Market Operator that is has little visibility or control of an energy source that is supply up to 60 per cent of daytime demand at times, and could reach 100 per cent within a few years.
The new standards for inverters are designed to prevent large amounts of rooftop solar suddenly disconnecting as a result of voltage disturbances. AEMO says recent events have revealed that up to a third of installed inverters have not been able to do this.
The appointment of agents is designed to allow AEMO to use their technologies to seek the widespread “switching off” of rooftop solar in the “rare” occasions it needs to do so in order to keep the grid secure.
The new standards come into force on September 28, but any new rooftop solar installation contract signed after August 10 is expected to conform with the new standards, leading the two peak solar bodies to complain of “chaos and confusion” and fears that installers will be left holding crippling amounts of unusable stock.
On Friday, the Office of the Technical Regulation released the list of the first batch of approved inverters, from four different suppliers, and a handful of approved companies that solar homes can nominate as “agents” to carry out any AEMO directive for rooftop solar systems to be disconnected.
The four inverters suppliers approved in the first batch include Enphase, Fronius, SMA, Sungrow, and more than 60 different models under those brands. You can find the full list here.
It is not clear that all those inverters have completed testing, or whether the manufacturers have simply signed an “undertaking document” that says the models will meet the standards. All manufacturers will be required “make good” any deficiencies should testing – which must be complete by March 31, 2021- reveal any poblems.
The list of approved agents include Solar Analytics, Redback Technologies, Luceo, and one agent – possibly a “Get Smart” fan – called “Agent 1 Pty Ltd.” All these agents will be required to provide a list and location of installations signed up to them, and have the ability to remotely disconnect the rooftop solar systems (effectively stopping them from exporting into the grid) should AEMO give the order to do so.
The list of approved inverters and agents will be expanded in coming weeks and months.
Similar rules are being developed for Western Australia, and will ultimately follow in other states in Australia as part of a broader distributed energy roadmap that will encourage aggregators, battery storage suppliers, demand management specialist and others to create a “two-sided” market.
This will allow more control over rooftop solar, and the creation of “virtual power plants” that can also provide grid services from the rooftop solar, battery storage and electric vehicles. It is not entirely clear how much control, in some of these programs, will be left in the hands of the household consumer, or the aggregators.
South Australia finds itself at the forefront of these changes because it has the highest penetration of rooftop solar in the country, the highest share of wind and solar in its grid (more than 55 per cent of its generation last year), and is heading towards “net 100 per cent” renewables by the end of the decade.
Energy minister Dan van Holst Pellekaan has described the new regulations as essential to ensure that the switch to a renewables grid can continue, and is a better option that placing limits on the amount of rooftop solar that can be installed.