Grid protection requirements for Solar PV installations over 30 Kilowatts
This information is for electrical contractors, and the solar industry. Solar PV installations with a combined inverter capacity over 30 Kilowatts require a grid protection system installed to comply with Australian Standards and the Electrical Safety Act 2022.
A property with total inverter capacity over 30 Kilowatts installed after 30 March 2017 without a grid protection system is considered non-compliant and may be disconnected from the grid by Power and Water.
What is a grid protection system?
A grid protection system is installed between the solar PV installation and the power grid to maintain safety of the system and stability of the power grid. A variety of manufacturers can provide different solutions to achieve this.
The grid protection system works in addition to the Anti Islanding function of individual inverters by disconnecting all of the Solar PV installations within the installation from the grid when there is a blackout or major voltage or frequency transitions.
This function prevents the individual inverters from forming their own grid within the installation and generating electricity which can be fed back into the power grid endangering maintenance, line workers and possibly the general public.
When is a grid protection system required?
A grid protection system is required when the total solar PV inverter capacity connected to a single grid connection point exceeds 30 Kilowatts. The following two examples require a grid protection system installed.
Compliance requirements for electrical contractors and the solar industry
The solar industry, including wholesalers, retailers, designers and installers should be aware of the requirements for grid protection systems and this information should be communicated to potential customers. Any Solar PV systems sold with a combined inverter capacity over 30 Kilowatts must include a grid protection system to be compliant.
Electrical contractors, solar designers and installers must ensure that a grid protection system is installed on a property where the combined solar inverter capacity is over 30 Kilowatts and is connected to a single grid connection point. The installation must comply with the following standards.
- Clause 3.4.4.3, ASNZS4777.1:2016 Grid connection of energy systems via inverters – Part 1: Installation requirements.
- Clause 4, ASNZS4777.2:2020 Grid connection of energy systems via inverters – Part 2: Inverter requirements.
Failing to do so is a potential breach of Section 29 of the Electrical Safety Act 2022 and Section 26 of the Work Health and Safety (National Uniform Legislation) Act 2011.