The Government of Western Australia will introduce new connection requirements for solar and battery systems on the Western Power network from 1 May 2026, reshaping how DER (distributed energy resources) are installed across the South West Interconnected System.
Published through an updated Wholesale Electricity Market Procedure, the changes apply to Standard Small User Facilities with a connection voltage below 1000 volt and an aggregate (distributed energy resources) capacity of 30 kVA (kilovolt-amperes) or less.
The reform enables greater flexibility in inverter system design up to 30 kVA under a standard connection, across both single and three-phase systems. This creates a pathway for larger rooftop solar and battery systems to export more energy to the network and greater access emerging products such as virtual power plants and flexible export arrangements.
Under the new framework, inverter systems must continue to comply with Australian/New Zealand Standard 4777.2, including installation using Australian Region B settings. Customers seeking to participate in export products, such as the Distributed Energy Buyback Scheme, will also need systems capable of remote disconnection and reconnection. Electricity retailers will nominate the technical solution installers must follow.
Installations that do not meet remote connectivity requirements must be export limited to 1.5 kilowatt and will not be required to support remote disconnection.
For customers of Synergy, commissioning must align with Synergy’s DER Functionality Requirements and Interconnection Handbook, including use of the CSIP-AUS communications protocol. The open-source standard is designed to support interoperability and national consistency.
The Government of Western Australia shared that the changes are a response to the unique operational challenges of the South West Interconnected System, the world’s largest isolated grid, where high rooftop solar penetration requires tighter coordination to maintain system stability in partnership with the Australian Energy Market Operator.
Nothing changes for installers before 1 May 2026, but industry is encouraged to review the Wholesale Electricity Market Procedure ahead of commencement. Following consultation with industry, the start date was delayed from February to May 2026 to allow additional preparation time.
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