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Information for installers

All applications to install renewable energy require our assessment to ensure they meet our technical requirements.

The Basic Micro EG Connection Technical Requirements or Low Voltage EG Connection Technical Requirements specify the minimum technical requirements for customers connecting renewable energy to our low voltage networks. 

Please be mindful that even when you feel you have complied with all the technical requirements, there is no guarantee that your application will be approved. For example, an application may not be accepted due to local network constraints, something you have no control over. You cannot proceed with any installation until you have received approval from Horizon Power in writing. Don’t forget to complete and attach the relevant schedules to your application.

Included in the technical requirements are specifications for generation controlled renewable energy installations. In these installations, your system production is controlled or managed to help maintain the reliability of power supply to all our customers. Generation controlled systems may require energy smoothing, feed-in management (FIM) or export limits and will need a System Impact Study to be undertaken, for which a fee applies. The System Impact Studies may identify the need for network augmentation however Horizon Power cannot confirm what these augmentation costs are until after the study is completed.

Some specific applications may also require zero export or feed in management (FIM) as part of the Horizon Power technical assessment process. 

Industry updates

New DER Technical Requirements

We’re working hard to fix the hosting capacity constraints and make solar available to more of our communities. The good news is, we're planning to release more capacity across many of our currently constrained towns over the next 12 months.

To facilitate hosting capacity increases, and to accommodate the transition to the new Australian Standard AS4777.2:2020, Horizon Power will shortly be updating its Technical Requirements for connection of DER systems.

The new Technical Requirements have been finalised and are available below - these come into effect on 18 December 2021.

What happens next?
Horizon Power is seeking industry feedback on the new Technical Requirements. Feedback may be emailed to up until Monday 15 November.

Technical information forum
Horizon Power hosted an industry technical forum on Thursday 4 November. This was an opportunity to understand more about these changes and provide your feedback. 

If you were unable to make it, please see below for a copy of the presentation and a recording of the session.

Requirements for new systems
In the meantime, please be aware of the following requirements in relation to transition to the new rules, and some immediate requirements for new systems:

Immediate requirements for all renewable energy systems
As part of the installation of a renewable energy system, the inverter firmware should be updated to the latest available firmware.

  • Inverters that are already compliant with the new AS4777.2:2020 standard must be configured to ‘Australia Region C’ settings.
  • For Inverters that are not compliant with AS4777.2:2020 but may be brought up to the new AS4777.2:2020 standard by updating the firmware, these inverters must have their firmware updated and be configured to ‘Australia Region C’ settings.

Updates to the latest firmware, and the use of the ‘Australia Region C’ settings will simplify the process of entering the required inverter settings.

Approval requirements - from 18 December 2021
As of 18 December 2021, Horizon Power will only accept applications for systems compliant to the new Technical Requirements, and AS4777.2:2020 (for Basic EG and LV EG connections).

Horizon Power uses the CEC inverter list and inverters must be accredited with the CEC. These inverters must be configured to ‘Australia Region C’ settings.

To facilitate the transition and processing of applications, Horizon Power will cease accepting applications with AS4777.2:2015 inverters from 10 December 2021.

Approval requirements - before 10 December 2021
Applications approved before 10 December 2021 with older AS4777.2:2015 compliant inverters can be installed after 10 December 2021 but must be installed and commissioned within three months of the date of application.

Any installation of an approved AS/NZS 4777.2:2015 after 18 December must be compliant with the inverter settings in the new Technical Requirements (‘Australia Region C’ settings).

Eligibility criteria: small-scale technology certificates and large-scale generation certificates
Compliance with AS/NZS 4777.2 current version is part of the Clean Energy Regulator (CER) eligibility criteria. With changes to the standard, the affected installation should refer to the regulations for eligibility criteria for these certificates, as provided by the Clean Energy Regulator on their website.

Horizon Power approval of an installation may not meet the eligibility criteria of CER. This is the responsibility of the user and supplier/installer to manage.

Can I still install a warranty replacement?
An inverter compliant with an earlier version of AS/NSZ 4777.2 can be replaced under warranty where:

  • The replacement inverter is the same make and model (like-for-like).
  • The replacement is for warranty purposes.
  • The inverter is set up to comply with the existing connection agreement.

Where the above requirements are not met, an AS/NZS 4777.2:2020 inverter compliant with the latest standards will be required.

From 1 July 2021, inverter systems in Western Australia must be compliant with new voltage disturbance requirements


From 18 December 2021 all inverters connecting to Horizon Power’s systems must be in accordance with AS/NZS 4777.2:2020 with the default regional setting selection set to “Australia C”. In order to keep power systems stable under high penetration of distributed energy resources, the new Australian Standard AS/NZS 4777.2:2020 now prescribes mandatory requirement for all inverters to have Voltage Disturbance Ride-Through (VDRT) capability.

Changes from 1 July, 2021

From 1 July 2021, all inverters in WA that meet the previous version of AS/NZS 4777.2:2015 are required to have this VDRT capability. This implementation requirement is being accelerated in WA at the recommendation of the Energy Transformation Taskforce to reduce the number of inverters with lower specifications being installed prior to December 2021.  

Therefore inverter based systems installed in WA between 1 July 2021 and 18 December 2021, which are registered under the outgoing AS/NZS 4777.2:2015 standard, will now be required to comply with the Short Duration Under Voltage Disturbance ride-through test procedure published by AEMO.

In determining approval for connection, inverters that meet the 2015 version of AS 4777.2 will be required to demonstrate compliance with the new voltage disturbance ride-through test protocol that was developed by the Australian Energy Market Operator. Horizon Power will be using a list of inverters compliant with the new test protocol as provided by the Clean Energy Council (CEC)

In order to allow time for projects already under consideration, applications which have been submitted to and approved by Horizon Power prior to 1 July 2021 under the old requirements will be permitted a one month grace period for physical installation and submission of all completion notices.

Watch the information session

To avoid confusion and ensure alignment across Western Australia, Horizon Power recently provided joint commentary at an industry information session hosted by Western Power and Energy Policy WA on Thursday 27 May 2021. Further explanation via a recording of that event can be found on the Western Power website. 

For further enquiries, please email

Horizon Power has recently updated its Technical Requirements with updated inverter settings, to ensure inverters do not curtail unnecessarily due to frequency fluctuations. 

The settings are the Over-Frequency Power Reduction settings, as described in Clause of AS/NZS 4777.2, including:

  • Activation Frequency – this is the frequency level at which over-frequency power reduction is activated.
  • Deactivation Frequency – this is the frequency level below which the over-frequency power reduction is deactivated (after a suitable delay – see the Deactivation Time) and the power level may be increased in accordance with the power rate limit.
  • Deactivation Time – this is the period of time for which frequency must be below the Deactivation Frequency before the over-frequency power reduction is deactivated and the power level may be increased in accordance with the power rate limit.
  • Fstop – this is the point on the Over-Frequency Power Reduction curve where the output of the system reaches zero.

The following settings are now required for the Over-Frequency Power Reduction settings, in non-standard network areas (i.e. outside the NWIS):

  • Activation Frequency: 50.6 Hz
  • Deactivation Frequency: 50.5 Hz
  • Deactivation Time: 20 sec
  • Fstop: 53.0 Hz

For systems with energy storage, the following settings are also required for Under-Frequency Charge Rate Limits (refer AS/NZS 4777.2 Clause, in non-standard network areas (i.e. outside the NWIS)::

  • Under-Frequency Activation Frequency: 49.4 Hz
  • Under-Frequency Deactivation Frequency: 49.5 Hz
  • Under-Frequency Deactivation Time: 20 sec
  • Fstop-CH: 45.0 Hz

Settings for standard network areas (i.e. NWIS) shall be as per Section 7.5.3 of AS/NZS 4777.2.

Proponents are required to ensure that all new systems installed comply with the new settings.  The Technical Requirements documents above have been updated with the new settings.

Stay up to date on solar releases and technical changes


Technical requirements and assessments

Renewable energy systems are categorised as follows:

  • Basic Micro EG Connection: Single phase, up to and including 10 kVA
  • Basic Micro EG Connection: Three phase, up to and including 30 kVA
  • LV EG Connection: Over 30 kVA but less than or equal to 200 kVA
  • LV EG Connection: Over 200 kVA but less than or equal to 1,000 kVA

These categories are further defined by whether your system is located in a Standard or Non-standard network. Horizon Power currently defines these as:

  • Standard networks: Towns located in the North-West Interconnected System (NWIS) which include Karratha, Roebourne, Port Hedland, South Hedland, Cossack and Point Samson.
  • Non-standard networks: All other towns located in Horizon Power’s service area

For all applications seeking to install over 1,000 kVA please contact

Prosumers If your intent is to connect a renewable energy system to a Horizon Power network to partially generate your own electricity and potentially export excess electricity to the Horizon Power network, then you are a Prosumer.

Prosumers are offered the Renewable Energy Buyback contract or the Renewable Energy Commercial Buyback contract.
For larger, non-residential systems, the total estimated annual renewable energy generation (kWh) should be no more than 20 per cent above the customers’ total annual consumption (kWh) prior to installing the renewable energy generation.
Independent Power Producer If your intent is to supply the renewable energy generated back to Horizon Power as a power producer, then you are an Independent Power Producer (IPP).

A Power Purchase Agreement is negotiated with each IPP.
If you don't meet the Prosumer rule above, you are deemed to be an Independent Power Producer (IPP).

Please complete and attach the relevant schedules to you application, as required for your system size.

Schedule 1

Proponent Compliance Checklist

This is a checklist comprising the key elements that need to be satisfied in order to comply.

Basic Micro EG Customer Compliance Checklist

LV EG Customer Compliance Checklist

Complete the checklist and enter any relevant comments. The checklist must be attached to all applications

Schedule 2

System Diagram

This is a conceptual diagram that illustrates the functional relationships between key subsystems using solid lines. The Customer’s System Diagram shall be in accordance with Appendix B ‘Connection Arrangement Requirements’ of the Basic Micro EG or Low Voltage EG Connection Technical Requirements.

Basic Micro EG System Diagram

LV EG System Diagram

A system diagram must be attached to all applications

Schedule 3

Circuit Diagram

This includes one or more diagrams detailing the electrical connections from the point of connection through to the renewable energy source. The Customer’s Circuit Diagram shall be in accordance with Appendix B and the other requirements of the Technical Requirements.

View a sample diagram

A circuit diagram must be attached to all applications

Schedule 4

Cable Data

This is the data associated with power cables connecting the Customer’s grid connected inverter to Horizon Power’s electricity distribution system. This includes the consumer mains cable.

Note that it is the Installer’s responsibility to ensure that voltage rise within the customer’s premises is in accordance with AS/NZS 4777.1

View sample data

Cable data must be attached to all applications.

Schedule 5

System Parameters

The key parameters that are to be implemented in the system are to be captured in this schedule. This will include information on power quality response modes, protection functions etc.

Basic Micro EG System Parameters

LV EG System Parameters

The System Parameters schedule must be attached to all applications.

Schedule 6

Registered Professional Engineer (NER or equivalent) sign-off letter

For all installations that require Generation Management, a registered Professional Engineer shall validate that the design is in accordance with the Connection Technical Requirements and provide supporting documentation. An installer may reuse a NER (or equivalent) declaration for multiple installations providing the installations do not differ with the NER (or equivalent) validated reference design in certain elements.

The National Engineering Register provides a directory of Chartered Professional Engineers.

To avoid any conflict of interest, Chartered Professional Engineers in the employ of Horizon Power are unable to provide NER sign-off letters.

A registered Professional Engineer sign-off must be attached to the application for all systems requiring generation management.

What are the most common reasons for an unsuccessful engineering assessment?

1. Ambiguity in the information supplied on the application
2. Inverter not on the CEC approved list
3. The voltage rise is too high
4. Local distribution transformer limits have been exceeded
5. There is a phase imbalance (greater than 2.5 kVA)
6. Generation management details have not been included in the application
7. Horizon Power system renewable energy limits reached

Generation management

Generation management allows more renewable energy to be installed across our electricity systems.

One of the challenges of managing renewable energy installations is the impact of their intermittent nature on the security and reliability of the power supply.

Generation management helps to overcome this challenge by controlling the electricity output of your rooftop solar. The availability of generation management installations means that we can allow more renewable energy to be installed across our electricity systems.

Generation management needs to be purchased in addition to the solar panels and inverter. In some towns, a solar system can only be installed with a generation management system.

Included in our technical requirements are specifications for generation managed renewable energy installations - where the electricity output can be controlled to help maintain the reliability of our power supply to all our customers.

Please note: The inverters connected to Horizon Power’s system shall be compliant as per the list managed by the Clean Energy Council (CEC).

Contractors and consultants are encouraged to demonstrate that their PV & Battery Systems comply with Horizon Power’s generation management (smoothing) requirements. 

The requirement for generation management depends primarily on the size of the renewable energy system you would like to install, whether it is in a Standard or Non-standard network, and the available hosting capacity in your town.

All ‘LV EG’ category renewable energy systems will require generation management.

All ‘Basic Micro EG’ category renewable energy systems are required to have FIM provisioning.

In certain circumstances, some ‘Basic Micro EG’ connections may require generation management where there is an increased risk to the reliability and security of supply in their town.

Please use the eligibility calculator to see if you are eligible to install rooftop solar, participate in our buyback scheme.

Eligibility calculator

Horizon Power prescribes three methods of generation management:

Generation Management Method


Renewable energy smoothing

Participating customers to install energy storage devices that release energy back to the grid to prevent system instability caused by fluctuations in renewable energy generation

Feed-in management (FIM)

Participating customers to allow Horizon Power to occasionally curtail the renewable energy installation’s generation output to prevent system instability

Zero export

Participating customers will not be allowed to export renewable energy into the system/distribution network.

This may apply in some of our towns.

Energy control and/or storage installations for renewable energy systems are already available in the market place and renewable energy suppliers and installers will be able to develop these so that they meet Horizon Power’s generation management technical requirements.

Horizon Power will provide information support to suppliers and installers who wish to develop this kind of energy storage installation.

There will be an additional cost from your installer for a generation managed system. Your renewable energy installer will be able to provide you with a quote for a suitable product to purchase.

You may also be required to pay a fee for Horizon Power to carry out a technical assessment of your renewable energy system application.