The Australian Standard AS/NZS 4777.1 (which sets the installation requirements for grid-connected inverters) has been updated and will be mandatory from 23 February 2025.
To align with this, Evoenergy is updating its connection requirements for solar and battery systems. Below is a summary of the key updates and what they mean for your installations.
Key updates to connection requirements
1. Simplified requirements for interface protection
For most commercial systems up to 200kVA, Evoenergy will no longer require central/interface protection. Previously, this was needed for systems above 30kVA.
What this means:
- This change is expected to reduce costs for most commercial solar installations over 30kVA.
- Interface protection will still be required in some cases, such as for older inverters that do not meet AS/NZS 4777.2:2020.
Example 1: A new system with 220kVA inverters and a generation limit of 200kVA set within the inverters → Interface protection is required because the total inverter nameplate rating exceeds 200kVA.
Example 2: An existing system with 100kVA of older inverters (non-compliant with AS/NZS 4777.2:2020) adding 50kVA of compliant inverters → Interface protection is required for the entire system.
Example 3: A new installation with 60kVA of inverters using an Inverter Power Sharing Device (IPSD, e.g., Solshare) → Interface protection is required for all IPSD installations exceeding 30kVA.
2. Increases to size limits for small EG systems
Evoenergy has reviewed the maximum inverter rating for small EG systems. This will allow larger battery installations for residential customers.
What is changing?
- Previously single-phase sites were limited to 15kVA including ESS, this has been increased to 20kVA.
- Three phase sites per phase limits have also been increased from 15kVA to 20kVA including ESS, and the maximum total rating of 30kVA has been removed.
3. Updated guidance on single-phase inverters at three-phase sites
The new standard provides clearer guidance on the use of single-phase inverters at three-phase properties, including battery systems such as Tesla Powerwall 3.
New sub-limits for single phase inverters at three phase sites
- 5kVA per phase with energy ports for PV
- 5kVA per phase battery only inverters
Why is this changing?
- These updates are part of the national standard AS/NZS 3000, which Evoenergy is required to follow.
- Customers with three-phase connections may need to consider alternative product configurations to ensure compliance.
Example 4: A three-phase site with a 10kVA single-phase hybrid inverter (with panels and battery) → Not allowed, as the single-phase limit is exceeded. A generation limit of 5kVA must be set, or a three-phase inverter used.
Example 5: A three-phase site with three single-phase 10kVA hybrid inverters, each installed on a separate phase and networked with phase balance protection → Allowed, as they function as a balanced three-phase system.
Example 6: A single-phase site with a 10kVA PV inverter and a 10kVA battery inverter → Allowed under the updated limits.
Example 7: A three-phase site with a 30kVA three-phase PV inverter + 30kVA three-phase battery inverter → Allowed.
Example 8: A three-phase site with a single-phase 5kVA PV inverter and a 5kVA single-phase hybrid inverter with only a battery connected on the same phase → Not allowed unless the PV ports on the hybrid inverter are permanently disabled or removed. A recommended approach would be to move the PV panels to the hybrid inverter and remove the existing PV inverter.
For three-phase sites, we recommend using three-phase inverters wherever possible. This will minimise the impact of per-phase limits on single-phase products.
Since the requirements now differ for single-phase and three-phase sites, it is essential to correctly indicate the site’s supply type on the SCR application and your single-line diagram (SLD). Evoenergy will conduct audits to ensure accurate information is provided. If we suspect a site is three-phase but has been submitted as single-phase, we may request a photo of the meter board or site main switch.
For sites with existing equipment, the entire site will need to comply with current requirements when any change is made. Exemptions may be granted for warranty replacements, provided the exact same product is used. In some cases, existing inverters may need generation limits programmed to meet updated single-phase inverter limits.
A three-phase upgrade does not require modifications to an existing solar system. However, any export controls must remain on the single phase they were originally approved for. If a customer wishes to switch to a three-phase export meter, the entire embedded generation system will need to meet the latest requirements, including single-phase inverter limits.
4. Refined approach to solar export limits
Evoenergy is updating the way solar exports are managed to align with industry practices and technical capabilities.
What is changing?
- Previously: A standard 5kVA per phase export limit applied.
- From 21 February 2025: Customers will have two options:
- 10kVA total export limit across all three phases (default setting).
- 5kVA per phase, if the inverter manufacturer confirms compliance.
- Customers seeking more than 10kVA total export can apply for a network assessment (fees apply).
Example 9: A 15kVA three-phase inverter → Allowed, as it cannot export more than 5kVA per phase.
Example 10: A 20kVA three-phase inverter → Requires an aggregate export limit of 10kVA, unless it can demonstrate the ability to implement a 5kVA per phase export limit
5. What this means for your installations
All installations from 21 February 2025 will need to follow these updated requirements.
For small jobs already in progress
- If you have an approval letter already, you still need to follow the new requirements if installing the system on or after 23/02/2025. Please withdraw and amend your application if required.
For LV jobs already in progress
If a Connection Proposal Letter (CPL) has not been issued, the new requirements will apply.
If a CPL has already been issued, installers can:
- Proceed with the existing approved design, or
- Request an amendment to follow the new guidelines (fees apply).
6. Next steps for installers
- A draft version of the updated small and LV requirements is linked for your reference, with the final version to be published on 21 February 2025, subject to minor refinements.
- These updates will bring cost savings to some commercial installations by removing the requirement for interface protection on systems ≤200kVA.
- Installers working on three-phase sites should take note of the revised approach to inverters, including considerations for single-phase battery systems.
- Changes to solar export limits will also take effect, with new default settings and application requirements to be aware of.
- Evoenergy appreciates your cooperation in implementing these updates. Please read the draft document and let us know if you have any questions.
Where to get more information
ENA has released a factsheet outlining some of the changes in AS/NZS 4777.1:2024 https://www.energynetworks.com.au/projects/national-grid-connection-guidelines/changes-to-inverter-installation-standards/
Smart Energy Council has a series of videos on the changes in AS/NZS 4777.1:2024 https://smartenergy.org.au/programs/smart-installer-program/
If you have questions specifically regarding Evoenergy requirements, please contact us at embeddedgeneration@evoenergy.com.au