This solar calculator shows what a system is deemed to generate where you live and what it costs installed. It is also an STC calculator: it works out how many small-scale technology certificates (STCs) a system earns for a 2026 installation from your Clean Energy Regulator zone, and adds payback when you enter your own tariffs.
Pick a system and your city, or tap a common system to start.
Your measurements
Estimated cost, Australia
$4,000 to $8,500 typical $6,000
Your numbers
- Clean Energy Regulator zone
- Zone 3 (rating 1.382)
- Deemed generation
- 9,121 kWh a year (about 25 kWh a day)
- Certificates (STCs) for a 2026 installation
- 45 (already counted in the installed prices below)
- Yearly value and payback
- Add your electricity price and feed-in tariff to see them
| Price row | Quantity | Rate | Low to high |
|---|---|---|---|
| 6.6 kW system (standard) | 1 | $4,000 to $8,500 installed | $4,000 to $8,500 |
Rates are the low, typical and high figures in our solar price guide, prices verified October 2026. An estimate only: get quotes to price your job.
Type the total on your quote to see how it compares with this estimate.
This job in 15 cities: typical $5,400 in Hobart to $6,900 in Sydney
| City | Low to high | Typical |
|---|---|---|
| Hobart | $3,600 to $7,650 | $5,400 |
| Adelaide | $3,675 to $7,800 | $5,500 |
| Geelong | $3,725 to $7,900 | $5,600 |
| Newcastle | $3,800 to $8,100 | $5,700 |
| Sunshine Coast | $3,875 to $8,250 | $5,800 |
| Gold Coast | $3,925 to $8,350 | $5,900 |
| Brisbane | $4,000 to $8,500 | $6,000 |
| Darwin | $4,000 to $8,500 | $6,000 |
| Byron Bay | $4,200 to $8,900 | $6,300 |
| Melbourne | $4,200 to $8,900 | $6,300 |
| Perth | $4,200 to $8,900 | $6,300 |
| Townsville | $4,325 to $9,200 | $6,500 |
| Wollongong | $4,325 to $9,200 | $6,500 |
| Canberra | $4,400 to $9,350 | $6,600 |
| Sydney | $4,600 to $9,800 | $6,900 |
Each city is priced from the rows in its own guide, cheapest typical figure first.
STC calculator: how many STCs a solar system earns
The number of STCs is worked out from three things:
- System size in kilowatts.
- Your zone rating. The Clean Energy Regulator splits Australia into four zones by postcode. Darwin is in zone 2 (rating 1.536); Sydney, Brisbane, Perth, Adelaide, Gold Coast, Canberra, Newcastle, Sunshine Coast, Townsville, Wollongong and Byron Bay are in zone 3 (rating 1.382); Melbourne, Hobart and Geelong are in zone 4 (rating 1.185).
- The deeming period, which is 5 years for a 2026 installation and drops by one each year until the scheme ends in 2030.
Multiply the three and round down. A 6.6 kW system in zone 3 earns 45 STCs for a 2026 installation; in zone 1 it earns 53. The installed prices in this calculator already have the certificates counted, so they are not taken off a second time.
How the calculation works
Zone. The Clean Energy Regulator puts every postcode in one of four zones by the level of solar radiation, and gives each zone a rating. In our guide Darwin is in zone 2 (rating 1.536); Sydney, Brisbane, Perth, Adelaide, Gold Coast, Canberra, Newcastle, Sunshine Coast, Townsville, Wollongong and Byron Bay are in zone 3 (rating 1.382); Melbourne, Hobart and Geelong are in zone 4 (rating 1.185). The national example uses zone 3, and you can change it.
Generation. One STC is equal to 1 MWh of renewable electricity, and a system earns its certificates on the kW of panels multiplied by the zone rating for each year of the deeming period. So kW × zone rating is the electricity the system is deemed to generate in a year: 6.6 kW in zone 3 is 9,121 kWh a year (about 25 kWh a day). Real output depends on the roof's direction and tilt, shading and the weather, so treat it as the deemed figure the certificates are based on, not a guarantee.
Certificates. The count is kW × zone rating × the deeming period, rounded down. The deeming period is 5 years for a 2026 installation and falls by one year each year until the scheme ends in 2030, which gives the example 45 STCs. Installers usually take the certificates as a discount, and the installed prices in our guide already include it.
Value and payback. The calculator does not guess your tariffs. Each kWh you use at home saves what you pay for electricity, and each kWh you export earns your feed-in tariff, so the yearly value sits between those two cases. Payback is the typical installed price divided by that yearly value.
Batteries are priced from the same guide. They earn certificates under their own rule, an STC factor per kWh of usable capacity, which this calculator does not work out.
Source for the figures that are not prices: Clean Energy Regulator (zones and zone ratings and what one certificate represents and the deeming period and the battery rule), checked October 2026.
Deemed output and STCs by zone (2026 installation)
Each figure is the system size multiplied by the zone rating; the certificates also multiply by the deeming period and round down.
| System | Zone 1 | Zone 2 | Zone 3 | Zone 4 |
|---|---|---|---|---|
| 6.6 kW | 10,705 kWh a year, 53 STCs | 10,138 kWh a year, 50 STCs | 9,121 kWh a year, 45 STCs | 7,821 kWh a year, 39 STCs |
| 10 kW | 16,220 kWh a year, 81 STCs | 15,360 kWh a year, 76 STCs | 13,820 kWh a year, 69 STCs | 11,850 kWh a year, 59 STCs |
| 13 kW | 21,086 kWh a year, 105 STCs | 19,968 kWh a year, 99 STCs | 17,966 kWh a year, 89 STCs | 15,405 kWh a year, 77 STCs |
Solar rates the calculator uses
These are the national figures from our solar price guide. Pick a city in the calculator and it switches to the same rows from that city's guide.
| Price row | Low | Typical | High |
|---|---|---|---|
| 6.6 kW system (standard) | $4,000 | $6,000 | $8,500 installed |
| 6.6 kW system (premium panels) | $6,500 | $8,000 | $10,500 installed |
| 10 kW system (standard) | $6,000 | $9,000 | $12,000 installed |
| 10 kW system (premium panels) | $10,000 | $12,500 | $15,000 installed |
| 13 kW+ commercial system | $12,000 | $16,000 | $22,000 installed |
| Battery 5 kWh (e.g. Sungrow) | $5,000 | $7,000 | $9,000 installed |
| Battery 10–13 kWh (mid-range) | $8,000 | $11,000 | $15,000 installed |
| Tesla Powerwall 3 (13.5 kWh) | $12,000 | $14,000 | $17,000 installed |
Solar prices by city
SydneyMelbourneBrisbanePerthAdelaideGold CoastCanberraHobartDarwinNewcastleGeelongSunshine CoastTownsvilleWollongongByron Bay
Frequently asked questions
How much electricity does a 6.6 kW solar system generate?
In zone 3 (rating 1.382) a 6.6 kW system is deemed to generate 9,121 kWh a year, about 25 kWh a day. In zone 4 (rating 1.185) the same system is deemed to make 7,821 kWh a year. Real output depends on orientation, tilt, shading and the weather.
How many STCs does a solar system get in 2026?
Multiply the system size in kW by the zone rating and the deeming period, then round down. The deeming period is 5 years for a 2026 installation, so a 6.6 kW system in zone 3 earns 45 STCs and a 10 kW system earns 69.
How much does a 6.6 kW solar system cost?
Our national solar guide puts a standard 6.6 kW system at $4,000 to $8,500 installed, with $6,000 typical, and one with premium panels at $6,500 to $10,500. A standard 10 kW system is $6,000 to $12,000. These prices already include the STC discount. Choose your city in the calculator to use that city's figures.
How long does solar take to pay back?
It depends on your tariffs and how much of the power you use at home. Enter what you pay for electricity and your feed-in tariff: the calculator divides the typical installed price by the yearly value of the deemed generation, from all of it exported to all of it used at home.
How much does a solar battery cost?
Our national guide lists a 5 kWh battery at $5,000 to $9,000 installed, a 10 to 13 kWh battery at $8,000 to $15,000 and a Tesla Powerwall 3 at $12,000 to $17,000.
Do solar batteries earn STCs?
Yes, under their own rule. The Clean Energy Regulator sets an STC factor per kWh of usable battery capacity, which changes over time, so this calculator prices the battery but does not work out its certificates.
How does an STC calculator work out the certificates for solar panels?
It multiplies the system size in kW by your zone rating and by the deeming period (5 years for a 2026 installation), then rounds down. A 6.6 kW system in zone 3 earns 45 STCs.
An estimate is a starting point. Get quotes from local solar businesses to price your job.
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