On 1 May 2026, new requirements will commence for new and upgraded rooftop solar and battery systems installed in the South West Interconnected System (SWIS). These requirements will apply to most households and small businesses installing or upgrading a solar or battery system.
The new requirements will support the continued uptake of these renewable technologies, while establishing a foundation for customers with larger systems to participate in new products. This includes the opportunity for customers to sign up to new products, access new revenue streams and reduce the grid’s reliance on emissions-intensive energy sources.
The new requirements also provide more flexibility in the installation of solar and battery systems to support a wider range of configurations behind-the-meter.
What is changing?
From 1 May 2026, the following changes will come into effect:
- Households and small businesses on a standard connection service will be able to install inverters up to 30 kVA (or aggregate of 30 kVA for multi-inverter sites). This includes rooftop solar, batteries, or other inverter-based sources. For sites with a single-phase connection, this represents an increase in the allowable installed generation capacity of 15 kW, aligning more closely with existing arrangements for three-phase connections.
- All new and upgraded systems must be able to be remotely disconnected and reconnected by the customers’ electricity retailer, or otherwise be export limited to 1.5 kilowatts (kW). The remote disconnection / reconnection capability must be set up by the installer at the point of installation. This is commonly known as emergency solar management and already happens for most residential systems as part of the distributed energy buyback scheme (DEBS).
- All inverters must comply with AS/NZS 4777.2: 2020., including that the grid code be set to “Australia Region B”.
More information on the specific requirements of the WEM Procedure for Standard Small User Facilities is available on the Western Power website.
General guidance on how solar and battery installers should apply these new technical requirements is available through Western Power’s Basic Embedded Generation Connection Technical Requirements web page.
What it means for customers
These changes will provide customers with larger solar and battery systems the opportunity to participate in new retailer products in the future, such as virtual power plants and flexible exports, and get more value by providing services to the grid.
The new requirements may result in changes to how systems are sized, configured and commissioned to support this participation. Your installer can explain what this means for your specific circumstances. Find out more on the New requirements for solar and batteries: information for consumers web page.
What it means for industry
Electricity retailers will be responsible for developing more specific processes at installation and commissioning that installers will need to use for new and upgraded installations to meet the updated Western Power technical requirements. For nearly all residential customers, Synergy is the electricity retailer. Synergy’s DER Functionality Requirements outlines how it intends to remotely manage solar and battery systems, and what installers and technology providers must do to enable this.
To facilitate lower-cost integration of consumer devices, the WA Government’s interoperability statement promotes a nationally consistent rollout of the Common Smart Inverter Profile - Australia (CSIP-AUS) to communicate with solar and battery systems. CSIP-AUS is an open source communications protocol that has been developed in partnership with other states and territories to reduce costs for equipment manufacturers and ensure the rollout of this capability is standardised across Australia.
The new rules do not specifically require CSIP-AUS. However, the WA Government is encouraging electricity retailers to adopt CSIP-AUS to manage compliance with these new requirements. This approach is nationally consistent with other electricity retailers and aggregators, given that CSIP-AUS is open-source protocol which is already supported by the majority of solar and battery systems sold in Australia.
Find out more on the New requirements for solar and batteries: Information for installers and retailers web page.
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