How we calculate "up to $8,000+ in solar and battery rebates"

The worked example

STC price assumed at $38. Installers typically pass on slightly less than the spot price to cover administration. Zone 3 covers Sydney, Brisbane, Perth, Adelaide and Canberra. Melbourne and Hobart are Zone 4, where the same system attracts $8,132, so the headline holds on the federal programs alone in every zone. A state scheme adds more where your state runs one: in Perth, the WA Residential Battery Scheme takes the smaller 13.3 kW and 14 kWh system to $8,368 for Synergy customers who meet its conditions.

What it does not include

• State schemes in the worked example above (they add to it where your state runs one, and are listed below because eligibility varies)
• Interest-free loans
• Feed-in tariffs
• VPP payments
• Anything means-tested or concession-only

Why 13.3 kW and 24 kWh

24 kWh is the smallest common battery size, three 8 kWh modules, that takes the federal programs past $8,000+ in every STC zone. That is why the headline says "up to": it is a ceiling for a large home, not what every household gets.

Most households are quoted a smaller battery. 14 kWh is the point where the federal battery rebate stops paying full rate. From 14 to 28 kWh it pays 60%, and from 28 to 50 kWh it pays 15%, so the rebate keeps growing with the battery but more slowly. On 13.3 kW and 14 kWh the federal programs come to $7,068 in Zone 3. We size to your usage, not to the headline, and the quiz works out the figure for your home.

13.3 kW is the largest array a standard single-phase home can install: a 10 kW inverter with the 133% panel oversize the STC rules allow. Three-phase homes can install more and earn more certificates, but most Australian homes are single-phase.

Other common systems (Zone 3 / Zone 4)

When the number changes

On 1 January 2027 the solar deeming period drops from 5 years to 4, cutting the solar component by about 20%. The battery STC factor also steps down in January and July each year. The STC spot price moves with the market. We check the headline against this working at every step-down, review this page monthly and note the date of the last review below.

State add-ons

• Western Australia: up to $1,300 (Synergy) or $3,800 (Horizon Power) from the WA Residential Battery Scheme, stackable with the federal rebate.
• Victoria: $1,400 on panels through Solar Victoria for eligible households. The battery loan program has closed.
• Australian Capital Territory: up to $5,000 through HESP for concession card holders ($2,500 on solar and $2,500 on one other upgrade, not batteries), plus Sustainable Household Scheme loans (up to $20,000 at 3% interest over up to 10 years).
• South Australia: VPP incentives. The SA Home Battery Scheme has closed.
• New South Wales: VPP incentives under the Peak Demand Reduction Scheme, plus a $15,000 interest-free Home Energy Saver loan. No upfront battery discount.
• Queensland: no state add-on.
• Northern Territory: no state add-on. The Home and Business Battery Scheme is closed.
• Tasmania: no state add-on.