Micro embedded generator standards define how small-scale generation systems, such as rooftop solar PV and battery systems, connect and operate safely on Australian distribution networks. They mainly apply to inverter-connected systems covered by AS/NZS 4777 and DNSP connection requirements. 

Key points

• Micro embedded generators are typically small-scale inverter-connected systems such as rooftop solar PV and battery systems.
• AS/NZS 4777 is the core standard for grid connection of inverter energy systems in Australia.
• DNSPs may apply additional technical requirements through model standing offers, connection agreements and local connection standards.
• Requirements can include inverter settings, export limits, phase balancing, metering, protection, commissioning and disconnection obligations.
• Product developers should check both national standards and DNSP-specific requirements before designing or supplying products for the Australian market.

What is a micro embedded generator?

A micro embedded generator is a small generating system connected to a distribution network, typically through an inverter. These systems are commonly rooftop solar PV, batteries or hybrid solar-battery systems installed at homes or businesses.

AS/NZS 4777.2: Grid connection of energy systems via inverters

AS/NZS 4777.2 (AS/NZS 4777.2:2020) specifies performance and grid interaction requirements for inverters connected to an LV network in Australia and New Zealand. It applies to inverters up to 200 kVA and governs how they respond to voltage, frequency, and grid disturbances. The standard ensures safe, stable integration of CER such as PV, BESS and Bidirectional EV Charging into the grid.

AS/NZS 4777.2 draws on international standards including IEC 62116 (anti-islanding protection), the IEC 61000 series (electromagnetic compatibility), and IEEE 1547 (grid interconnection). However, it adapts these to suit the unique characteristics of the Australian grid, particularly its long radial feeders, low fault levels, and high CER penetration.

Specific Australian requirements include:

• Region Code implementation: Mandates the use of region codes embedded in inverter firmware. These codes preconfigure voltage and frequency trip limits, ramp rates, and grid support functions based on AEMO system security requirements.
• Voltage ride-through requirements: Requires inverters to remain connected during short-term voltage disturbances, including sags down to 50% and swells up to 130%, with defined ride-through curves. Compared to international grid codes, AS/NZS 4777.2 requires inverters to remain connected through a wider range of voltage and frequency disturbances.
• Mandatory grid support functions: Volt-var, volt-watt, and frequency-watt modes are mandatory and must be enabled by default. This is generally more prescriptive than international grid codes and there can be no reliance on installer configuration.
• Demand response modes: Inverters must be capable of responding to DRM signals, which are specified in AS/NZS 4755.3.5 for inverter energy systems. Specifically, DRM0 is a mandatory mode that instructs the inverter to disconnect. The standard does not specify the communication protocol or interface through which DRM signals must be received. Instead, it allows flexibility for manufacturers to implement DRM0 using a AS/NZS 4755.1 compliant interface, IEEE 2030.5 (Smart Energy Profile 2.0), Sunspec Modbus, or other DNSP-approved methods.

AS/NZS 4777.2 certification and product listing

All Micro EGs must be certified to AS/NZS 4777.2 through an accredited testing and listing process overseen by the CEC. The certification and listing process is summarised below.

• Laboratory testing: Inverters must undergo testing at a laboratory accredited by the National Association of Testing Authorities (NATA) or an equivalent ILAC MRA signatory. The testing must demonstrate compliance with all mandatory clauses of AS/NZS 4777.2, including voltage and frequency ride-through, anti-islanding protection, and grid support functions. Testing must also verify support for DRM0 and generation limiting capabilities.
• Test report submission: The manufacturer or local representative submits the test report to the CEC along with a completed application form, product datasheets, installation manuals, and firmware version details. The documentation must clearly show how the inverter meets the functional requirements of the standard. The applicant must declare which region codes the inverter supports, as these determine the inverter’s grid interaction settings for different jurisdictions. A fee is charged by the CEC for reviewing documentation.
• CEC review: The CEC reviews inverter test reports to confirm testing outcomes such as whether region codes are correctly implemented and locked, grid support functions operate as required, and DRM0 are present. It also assesses supporting documentation, including installation manuals and firmware version declarations. The CEC may conduct technical audits or request additional evidence to verify compliance.
• CEC listing: Inverters that pass this review are listed on the CEC Approved Products List, which is essential for grid connection approval (unless a specific exemption is granted by a DNSP).
• Ongoing compliance: Any firmware updates or other product modifications that affect grid behaviour require re-testing and re-submission. The CEC may conduct post-certification audits or request additional documentation to confirm continued compliance and maintain listing.

Related articles

• Connecting a generator to a distribution network
• Connecting a Micro EG (<30 kW)
• CER technical and interoperability standards
• Standards for electrical installations in Australia
• Other standards