Rebates

Solar and battery rebates in WA, explained

By Christy Britton, GridLine Solar · Figures checked October 2026

There are three separate things people call "the rebate" in Western Australia. Two of them come off your quote. The third is a bill credit you earn for years afterwards. They're worked out differently, so it pays to look at each one on its own.

1. The federal solar discount (STCs)

When an accredited installer puts in a solar system, the system creates small-scale technology certificates (STCs). You sign them over to the installer and the value comes straight off your price. Nobody applies for anything.

The number of certificates depends on three things:

• System size in kilowatts of panels.
• Where you live. Perth is in zone 3, which gives 1.382 certificates per kilowatt for each year of "deeming".
• The year it's installed. Deeming is 5 years for systems installed in 2026 and drops by one each January until the scheme ends after 2030.

A 6.65 kW system (fourteen 475 W panels) installed in Perth this year works out at 6.65 × 1.382 × 5 = 45 certificates, rounded down. The same system installed in January 2027 gets 36. Certificates trade at roughly $37 each at the moment, so that drop is worth about $330 on a small system and more on a big one.

2. The federal battery discount (Cheaper Home Batteries)

Since July 2025 home batteries create certificates too, under the Cheaper Home Batteries Program. It works the same way as solar: the installer claims the certificates and takes the value off your quote.

The amount is set per kilowatt-hour of usable battery capacity, not the number on the box. A SolaX T-BAT HS28.8, for example, is 29.4 kWh nominal but 26.4 kWh usable, and only the 26.4 counts.

Two rules changed on 1 May 2026:

• Bigger batteries earn less per kWh. The first 14 kWh gets the full rate. From 14 to 28 kWh you get 60% of it, from 28 to 50 kWh you get 15%, and nothing past 50 kWh.
• The rate drops every six months instead of once a year.

What that means in dollars, at about $37 a certificate:

• A 13.2 kWh battery installed in November 2026: 13.2 × 6.8 = 89 certificates, roughly $3,290. The same battery installed in February 2027: 75 certificates, roughly $2,780.
• A 26.4 kWh battery installed in November 2026: 95 certificates for the first 14 kWh plus 50 for the rest, 145 in total, roughly $5,370.

The rate is set by the day the battery is installed, not the day you sign. If a quote was written for a 2026 install and the job slips into January, the discount shrinks. Ask how your quote handles that before you sign.

3. The WA Residential Battery Scheme

This is the State Government's scheme, separate from the federal one, and you can get both. As of the latest WA Government update:

• Rebate: up to $1,300 for Synergy customers and up to $3,800 for Horizon Power customers. You don't choose your retailer; it's set by your address.
• The catch: you have to sign up to a virtual power plant (VPP) offered by Synergy or Horizon Power. That lets your retailer draw on your battery at certain times.
• Battery rules: at least 5 kWh usable, on the approved product list, one per property.
• Interest-free loans: $2,001 to $10,000 over 3 to 10 years, for households earning under $210,000 a year, through Plenti. A credit check applies, and the loan can cover solar as well as the battery.
• Who applies: the battery vendor, on your behalf. The vendor has to be registered for the scheme.

To be upfront: GridLine isn't registered as a vendor for the WA scheme yet, so we can't lodge it for you at the moment. The federal discount is unaffected. If the $1,300 or the loan matters to you, ask us where that's up to before you sign.

What isn't a rebate: export credits

Synergy pays you for electricity your system sends back to the grid under the Distributed Energy Buyback Scheme (DEBS). From 1 July 2026 that's 10c per kWh between 3pm and 9pm and 2c at other times. It shows up as a credit on your bills for as long as you're on the scheme. It doesn't reduce your installation price, and a quote that adds it to the "rebates" is mixing two different things. There's more on this in our guide to DEBS and REBS.

Things to check on any quote

• Each discount shown as its own line, with the number of certificates.
• The battery's usable capacity, not just the model name.
• Which install period the battery discount was worked out for.
• Whether the WA scheme is included, and if so, whether the installer is actually registered to lodge it.