New Zealand’s solar grid connection rules sit at the intersection of the Electricity Authority’s Part 6 Code, the AS/NZS 4777 standard series, and individual Lines Company requirements. Installers who understand how these three layers interact can get systems connected faster and avoid the most common rejection reasons: wrong inverter settings, incomplete documentation, and mismatched export limits.
This guide explains the technical requirements for connecting solar to New Zealand’s distribution network in 2026. It covers the standards, the application processes, the protection settings, and the specific requirements of major Lines Companies.
Critical Compliance Point
From 7 November 2025, New Zealand adopted the Australia A Region voltage setting (258V 10-minute average). Inverters configured to the old New Zealand-specific profile (230V +6%) will fail inspection if installed after this date. Always verify the voltage protection settings before commissioning.
The Core Rule: Part 6 of the Electricity Industry Participation Code
Part 6 of the Code governs how distributed generation connects to New Zealand’s electricity distribution networks. It is the legal foundation that all Lines Companies must follow.
Connection Processes
The Code defines four processes based on system size and complexity:
| Process | System Size | Timeline | Assessment Level |
|---|---|---|---|
| Part 1A | under 10 kW | 10 business days | Simplified (deemed approval if no response) |
| Process 1 | under 10 kW | Varies | Standard |
| Process 2 | 10 kW to 300 kW | Varies | Full technical assessment |
| Process 3 | 300 kW and above | Negotiated | Custom connection contract |
For residential and small commercial solar, Part 1A is the relevant pathway. The key advantage is the deemed approval provision: if the distributor does not respond within 10 business days, the application is automatically approved.
Regulated Terms
Schedule 6.1 of the Code contains the regulated terms that apply when no negotiated contract exists. These terms cover:
- Construction and connection obligations
- Operation and maintenance requirements
- Protection and safety requirements
- Conditions for disconnection
- Compliance with the distributor’s connection and operation standards
Installers should request a copy of the distributor’s connection standards before starting work. These standards supplement the Code and AS/NZS 4777 with distributor-specific requirements.
AS/NZS 4777.2:2020 — Inverter Requirements
AS/NZS 4777.2:2020 is the performance standard for grid-connected inverters in Australia and New Zealand. Amendment 2 (2024) introduced additional requirements with full compliance required from 23 August 2025.
Anti-Islanding Protection
Anti-islanding is the most critical safety function. Inverters must detect when the grid is de-energised and stop exporting power within defined time limits.
Requirements:
- Passive anti-islanding: Continuous monitoring of voltage and frequency. Must trip when thresholds are exceeded.
- Active anti-islanding: At least one active method (frequency drift, impedance detection, or similar) to detect islanding conditions that passive methods might miss.
- Automatic disconnection: Must operate within the time limits specified in the standard.
- Minimum reconnection time: 60 seconds after grid voltage and frequency return to normal.
Export control systems (used to limit export power) must not interfere with anti-islanding performance. This is a common failure point during inspection.
Voltage and Frequency Protection Settings
From 7 November 2025, New Zealand adopted the Australia A Region voltage profile. The key settings are:
| Parameter | Setting | Trip Delay |
|---|---|---|
| Vnom max (10-min average) | 258V | 3 seconds max |
| Overvoltage stage 1 | 265V | 1 to 2 seconds |
| Overvoltage stage 2 | 275V | 0.2 seconds |
| Undervoltage stage 1 | 180V | 10 to 11 seconds |
| Undervoltage stage 2 | 70V | 1 to 2 seconds |
| Overfrequency | 55 Hz | 0.2 seconds |
| Underfrequency | 45 Hz | 1 to 2 seconds |
| Minimum reconnection time | 60 seconds | Fixed |
Installers must verify these settings during commissioning. Many inverters ship with factory defaults that do not match the New Zealand profile.
Volt-Watt and Volt-Var Response
These grid support functions help manage voltage rise caused by solar exports:
Volt-watt response: Reduces active power export as local voltage increases. This prevents overvoltage at the point of connection and reduces the risk of inverter trip events.
Volt-var response: Provides reactive power support. At high voltages, the inverter absorbs reactive power. At low voltages, it injects reactive power. This helps stabilise local voltage.
Both modes must be enabled for Part 1A applications. The specific response curves are defined in AS/NZS 4777.2:2020.
Harmonic and Power Quality Limits
Inverters must limit harmonic distortion, flicker, and voltage fluctuations to levels defined in the AS/NZS 61000 series. Key limits include:
- Total harmonic distortion of current: typically under 5%
- Individual harmonic orders: limits vary by harmonic number
- Flicker (Pst): under 1.0
- Voltage fluctuation: within distributor-specified limits
Compliance Certification
All inverters must have a Declaration of Conformity (DoC) from an IANZ-accredited or recognised test laboratory. The DoC must confirm compliance with AS/NZS 4777.2:2020 including Amendments 1 and 2.
Some Lines Companies maintain approved inverter lists. If an inverter is not on the list, the installer must provide the DoC with the application.
AS/NZS 4777.1:2024 — Installation Requirements
The 2024 update to the installation standard introduced several changes relevant to New Zealand installers.
Key Changes from the 2016 Version
| Change | Detail | Impact |
|---|---|---|
| Inverter Power Sharing Devices (IPSD) | Enables shared solar in multi-dwelling buildings | New opportunity for apartments and townhouses |
| V2G/V2H provisions | Covers bidirectional EV charging | Future-proofs installations for vehicle-to-grid |
| Phase balance limits | 30 kVA single-phase, 5 kVA imbalance for multi-phase up to 50 kVA | Clarifies multi-phase system sizing |
| Interface protection | Replaced central protection for systems under 200 kVA | Simplified protection for commercial systems |
| Supply type definitions | Refined definitions for different connection types | Clearer application of requirements |
Installation Requirements
All grid-connected solar installations must comply with:
- AS/NZS 3000: Wiring Rules (general electrical installation)
- AS/NZS 5033: PV array installation (DC cabling, mounting, earthing)
- AS/NZS 4777.1: Grid connection installation (AC isolation, point of connection, labelling)
Key installation requirements include:
- AC and DC isolation switches within specified distances of the inverter
- Correct cable sizing for voltage drop and ampacity
- Proper earthing and bonding of all metalwork
- Clear labelling at the point of connection, meter board, and isolation points
- Compliance with distributor-specific connection standards
The Electricity (Safety) Regulations are expected to cite AS/NZS 4777.1:2024 by the end of 2025, making the 2024 version mandatory.
Export Limits and Control
Export limits are one of the most contentious areas of New Zealand solar policy. The rules changed significantly in 2025 and 2026.
Historical Context
Until 2025, most Lines Companies applied a 5 kW export limit for residential single-phase connections. This was a de facto standard that limited the size of residential systems and reduced the value of solar for high-export households.
New Default: 10 kW
From April 2026, the EA mandates a default 10 kW export limit for small-scale distributed generation. This applies where network conditions permit.
Key points:
- The 10 kW limit is a default, not a guarantee
- Lines Companies may set lower limits where justified by network constraints
- Dynamic export limits are permitted and encouraged
- The limit applies to the export power, not the inverter nameplate capacity
Dynamic Export Limits
Dynamic export limits adjust in real time based on network conditions. During periods of low demand and high solar generation, the limit may decrease. During periods of high demand, the limit may increase above 10 kW.
Vector and other distributors have advocated for dynamic limits over static caps. The technology requires smart inverters and communication infrastructure that is not yet universal in New Zealand.
Export Control Methods
| Method | Description | Typical Use |
|---|---|---|
| Hard limit | Inverter disconnects when limit exceeded | Simple, reliable, but causes generation loss |
| Soft limit | Inverter reduces output to stay under limit | Preferred method, gradual reduction |
| Zero export | No power exported to grid | Used where export is not permitted |
| Dynamic | Limit varies based on real-time conditions | Emerging, requires smart inverter |
For Part 1A applications, the export power must remain below the distributor’s threshold. Installers should confirm the specific limit for the property address before finalising system design.
Lines Company-Specific Requirements
While the Code and AS/NZS 4777 provide the national framework, each Lines Company adds its own requirements. Here are the major distributors.
Vector (Auckland)
- Region: Auckland and surrounding areas
- Export limit: 10 kW default (supports dynamic limits)
- Application: Online DG portal
- Special requirements: Both volt-var and volt-watt must be enabled; inverter must be AS/NZS 4777.2:2020 compliant
- Response time: 10 business days for Part 1A
Powerco
- Region: Waikato, Taranaki, Bay of Plenty, Wellington, Manawatu
- Export limit: 10 kW default
- Application: Email or online form
- Special requirements: Technical requirements document specifies protection settings and power quality limits
- Response time: 10 business days for Part 1A
Orion (Canterbury)
- Region: Canterbury
- Export limit: 10 kW default
- Application: Online portal
- Special requirements: Network impact assessment for systems approaching 10 kW
- Response time: 10 business days for Part 1A
Unison Networks
- Region: Hawke’s Bay, Rotorua, Taupo
- Export limit: 10 kW default
- Application: Email or online form
- Special requirements: Standard distributed generation connection process
- Response time: 10 business days for Part 1A
Aurora Energy
- Region: Dunedin, Central Otago, Queenstown
- Export limit: 10 kW (increased from 5 kW in August 2025)
- Application: Online portal
- Special requirements: Was an early adopter of the 10 kW limit
- Response time: 10 business days for Part 1A
NorthPower
- Region: Northland
- Export limit: 10 kW default
- Application: Online portal
- Special requirements: Technical requirements standard for small to medium distributed generation
- Response time: 10 business days for Part 1A
Import/Export Metering
Bi-directional metering is required for all grid-connected solar systems. The meter records both electricity imported from the grid and exported to the grid.
Meter Types
| Type | Function | Typical Use |
|---|---|---|
| Basic bi-directional | Records import and export kWh | Standard residential |
| Time-of-use | Records import and export by time period | Time-of-use retail plans |
| Smart meter | Remote reading, interval data | Most new installations |
Meter Installation
The electricity retailer typically arranges meter installation or reconfiguration. The process is:
- Installer notifies the retailer that solar is being installed
- Retailer arranges for a bi-directional meter (may involve the metering equipment provider)
- Meter is installed or reconfigured after the solar system is commissioned
- Billing switches to the new import/export arrangement
Some retailers charge a fee for meter reconfiguration. Others include it at no cost. Installers should advise customers to confirm this with their retailer before installation.
Step-by-Step: How to Comply
Verify inverter AS/NZS 4777.2:2020 compliance
Check that the inverter model is listed on the distributor’s approved inverter list or that the manufacturer can provide a Declaration of Conformity from an IANZ-accredited or recognised test laboratory. The inverter must support volt-watt, volt-var, anti-islanding, and the full voltage and frequency protection suite required by AS/NZS 4777.2:2020 with Amendments 1 and 2.
Configure inverter protection settings for New Zealand
Set the inverter to the New Zealand voltage and frequency protection profile. From November 2025, use the Australia A Region setting: 258V for the 10-minute average. Enable both volt-var and volt-watt response modes. Set anti-islanding to passive plus active methods. Confirm the minimum reconnection delay is 60 seconds. Document all settings for the inspection.
Submit a Part 1A distributed generation application
Apply to your Lines Company using the Part 1A simplified process. Include the completed application form, inverter datasheets with Declaration of Conformity, a single-line diagram showing all equipment, and the proposed export limit. The distributor must respond within 10 business days or the application is deemed approved.
Install the system per AS/NZS 4777.1:2024 and AS/NZS 3000
The EWRB-registered electrician installs DC cabling, AC cabling, isolation switches, and earthing per AS/NZS 3000 and AS/NZS 5033. The grid connection wiring must comply with AS/NZS 4777.1:2024, including correct labelling, isolation requirements, and point of connection details.
Commission and test the system
The electrician performs commissioning tests including insulation resistance, polarity, earth continuity, and anti-islanding functionality. Record all test results. Verify that the inverter disconnects within required time limits during simulated grid loss and reconnects only after the 60-second minimum delay.
Obtain Certificate of Compliance and Record of Inspection
The installing electrician issues a Certificate of Compliance (CoC) within 20 working days. An independent electrical inspector issues a Record of Inspection (RoI). Both documents must be provided to the Lines Company before final energisation approval. The inspector verifies compliance with all applicable standards including AS/NZS 4777.2 settings.
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Common Mistakes
| Mistake | Why It Happens | Correct Approach |
|---|---|---|
| Inverter set to old NZ voltage profile (230V +6%) | Installer unaware of November 2025 change | Set to Australia A Region (258V) for all new installations |
| Missing Declaration of Conformity | Ordered inverter from grey market | Only use inverters with IANZ-recognised DoC |
| Export control interferes with anti-islanding | Poorly configured soft limit | Test anti-islanding with export control active |
| Wrong DG process selected | Installer assumes Part 1A without checking | Verify all criteria: size, phase balance, compliance modes |
| Phase imbalance over 5 kVA | Poor system design on multi-phase | Size inverters to stay under 5 kVA imbalance |
| Missing volt-var or volt-watt | Inverter capability not enabled | Both modes must be active for Part 1A |
Frequently Asked Questions
What is AS/NZS 4777.2 and why does it matter for solar in New Zealand?
AS/NZS 4777.2:2020 is the joint Australian-New Zealand standard that specifies performance and safety requirements for grid-connected inverters. It mandates anti-islanding protection, voltage and frequency protection settings, volt-watt and volt-var response modes, and harmonic limits. All inverters connecting to New Zealand’s distribution network must comply. Non-compliant inverters will be rejected by Lines Companies.
What are the anti-islanding requirements for NZ solar inverters?
Inverters must detect grid loss and disconnect within specified time limits. AS/NZS 4777.2:2020 requires both passive anti-islanding (voltage and frequency threshold monitoring) and active anti-islanding (frequency drift, impedance detection, or similar). The minimum reconnection time after grid restoration is 60 seconds. Export control systems must not interfere with anti-islanding performance.
What is the default solar export limit in New Zealand?
From April 2026, the Electricity Authority mandates a default export limit of 10 kW for small-scale distributed generation where network conditions permit. This replaced the previous 5 kW standard. Lines Companies may still set lower limits in areas with transformer or voltage constraints. Dynamic export limits, which adjust based on real-time grid conditions, are also being introduced.
What voltage settings must NZ solar inverters use?
From 7 November 2025, New Zealand adopted the Australia A Region voltage setting of 258V for the 10-minute average (Vnom max). Other key settings include: overvoltage stage 1 at 265V (1 to 2 second trip), overvoltage stage 2 at 275V (0.2 second trip), undervoltage stage 1 at 180V (10 to 11 second trip), undervoltage stage 2 at 70V (1 to 2 second trip), overfrequency at 55 Hz (0.2 second trip), and underfrequency at 45 Hz (1 to 2 second trip).
How do I qualify for the Part 1A simplified grid connection process?
To use Part 1A under the Electricity Industry Participation Code, your system must: have total inverter capacity under 10 kW; use single-phase inverters under 5 kVA (or phase imbalance under 5 kVA for multi-phase); use only AS/NZS 4777.2:2020 compliant inverters; have both volt-var and volt-watt response modes enabled; and keep export power below the distributor’s threshold. The distributor must process Part 1A applications within 10 business days.
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