Replacing a solar inverter in WA: the 2026 rules and cost

Published 23 October 2026

What changed for solar on 1 May 2026

Energy Policy WA's rules for new and upgraded rooftop solar and battery systems in the South West Interconnected System, which takes in Busselton, started on 1 May 2026. Households on a standard connection can install inverters up to 30 kVA, and the system must either:

• be able to be remotely disconnected and reconnected by your electricity retailer, set up by the installer at installation, which Energy Policy WA says is commonly called emergency solar management, or
• be limited to exporting 1.5 kW. Energy Policy WA says personal use of your solar or battery isn't affected

If you don't want to take part in export products, or the site can't keep a stable internet connection, Energy Policy WA says you don't have to stay connected after installation testing, and the system is set to the 1.5 kW limit instead. There are no penalties if a device loses communication; it falls back to a lower export limit. Systems installed or upgraded before 1 May 2026 aren't affected.

Does replacing an inverter trigger the 2026 rules?

It depends on what goes in. Western Power and Energy Policy WA separate replacements from upgrades:

How WA treats an inverter replacement

From Western Power's inverter application page and its 2026 Basic Embedded Generator technical requirements, and Energy Policy WA's pages for consumers and installers, checked 22 October 2026. Western Power says replacement equipment must meet current approval requirements, and that a three-phase connection replacing a single-phase inverter with one over 3 kVA must apply.

Western Power's technical requirements set out what a replacement must be. Where the same model isn't available, it's a current model within 0.1 kVA of the old inverter's size, compliant with AS/NZS 4777.2:2020, running the latest firmware and set to "Australia Region B". If the size changes, it's a new application. The inverter must also be on the Clean Energy Council's list of approved grid-connect inverters.

If you're adding a new inverter, including swapping to a bigger one, Energy Policy WA says all the inverters at your home must be able to communicate with each other as a single system.

REBS or DEBS: will a replacement change your buy-back rate?

If you're still on the older Renewable Energy Buyback Scheme (REBS), check before the work. Synergy says that if you make changes to your system, you may not be eligible to keep receiving REBS, and Energy Policy WA says REBS rates continue unless a change is made to the system. Neither says whether a like-for-like replacement counts, so ask Synergy before you book the replacement.

New and upgraded systems go on the Distributed Energy Buyback Scheme (DEBS). Synergy's schedule from 1 July 2026 pays 10 cents per kWh exported between 3pm and 9pm, and 2 cents at other times, excluding GST unless its terms say otherwise.

Signs your solar inverter needs replacing

Solar Victoria (interstate) puts it simply: in a grid-connected system, an inverter failure means your panels are doing nothing until it's repaired or replaced. It says panels should last more than 25 years, but inverters aren't generally expected to last much more than 10 or 15, so most systems need at least one replacement.

Most inverters show their status with a light or screen. On a Fronius Primo GEN24, for instance, Fronius says a green light means it's operating correctly, yellow means standby or not configured, and red means a critical status with no power fed into the grid. Check your own inverter's manual, as the signals differ between brands. Perth Solar Warehouse, a Perth solar business, says internal repairs are often a sign an inverter is approaching the end of its life.

Before paying for a replacement, check the inverter's warranty card or the manufacturer's website, because a warranty replacement is the case the 2026 exemption covers. Don't open the inverter or its cabling: that's work for a licensed electrical contractor.

Solar inverter replacement cost

Published inverter replacement prices

Prices as published, checked 22 October 2026. What's The Damage's figures are for the Perth metro area, updated October 2026. WhySolar's (13 April 2026) are national and don't say whether installation or GST is included. We found no South West installer publishing an inverter replacement price, so Busselton jobs can differ.

Western Power and Synergy fees

Western Power's application page and Synergy's DEBS price schedule from 1 July 2026, checked 22 October 2026. A like-for-like replacement doesn't need a new Western Power application. Synergy lists these fees in its DEBS schedule; ask Synergy which, if any, apply to your replacement.

Hybrid inverters, which can also run a home battery, cost more than string inverters. If you're thinking about a battery, see the solar battery cost guide before choosing a replacement, since adding a battery counts as an upgrade under the 2026 rules.

Who can replace a solar inverter in WA?

A licensed electrical contractor. Building and Energy says work on the inverter, wiring and switchboard of a solar system is electrical installing work in most cases, and solar businesses without an electrical contractor's licence must have it done by a licensed electrical contractor, who is responsible for its safety. Solar Accreditation Australia (SAA) accredits solar installers under the federal small-scale scheme, which the Clean Energy Regulator says adds assurance over and above state requirements for electricians.

Homeowners are responsible for their inverter's connection to Western Power, but Western Power says you can authorise your solar supplier to apply for you. There's no fee, and it says most applications are approved within an hour, or 15 business days where a technical assessment is needed. A replacement with a different specification, such as a bigger or hybrid inverter, should come with an Electrical Safety Certificate. A like-for-like swap may count as maintenance work, which doesn't need one, so ask the contractor. See the Electrical Safety Certificate in WA.

Common questions