3 kW solar prices in each capital city
| City | Standard | Per watt | Premium |
|---|---|---|---|
| Adelaide | $3,610 | $1.20 | $4,350 |
| Brisbane | $4,120 | $1.37 | $4,920 |
| Canberra | $4,030 | $1.34 | $4,740 |
| Darwin | $6,250 | $2.08 | $7,050 |
| Hobart | $4,310 | $1.44 | $5,160 |
| Melbourne | $3,980 | $1.33 | $4,570 |
| Sydney | $3,670 | $1.22 | $4,470 |
| Perth | $3,060 | $1.02 | $3,850 |
| National average | $4,130 | $1.38 | $4,890 |
The prices above already take off the federal discount. In 2026 a 3 kW system creates 20 small-scale technology certificates (STCs) in zone 3, which covers Sydney, Brisbane, Adelaide, Perth and Canberra, and 17 in zone 4, which covers Melbourne and Hobart. At the $40 Clearing House price that is up to $800 and $680, though certificates usually trade a little below it. See how STCs work.
How much power a 3 kW system makes
| CER zone | Example places | Per day | Per year |
|---|---|---|---|
| Zone 1 | Alice Springs | 13.3 kWh | 4,866 kWh |
| Zone 2 | Darwin | 12.6 kWh | 4,608 kWh |
| Zone 3 | Sydney, Brisbane, Adelaide, Perth, Canberra | 11.4 kWh | 4,146 kWh |
| Zone 4 | Melbourne, Hobart | 9.7 kWh | 3,555 kWh |
The Clean Energy Regulator rates every postcode by how much sunshine it gets. Its zone ratings are averages for a well-placed system, so treat them as a guide. A north-facing roof with no shade comes closest to these figures; east and west roofs, shade and hot panels all make less. Run your own numbers in the solar calculator.
Who a 3 kW system suits
- Households of one or two people who use most of their power during the day.
- Homes with a small or shaded roof, such as townhouses, where more panels will not fit.
- Anyone adding to an existing system, where a few more panels top up output.
Why small systems cost more per watt
Installing solar has fixed costs that barely change with size: the trip, scaffolding or roof safety gear, the inverter, the switchboard work and the network paperwork. Spread over 3 kW they add more to each watt. On the national averages, 3 kW works out at $1.38 a watt, against $1.05 for 6 kW and $0.98 for 10 kW.
That is why installers often suggest going bigger if the roof allows. Extra panels are cheap compared with the base cost, and with feed-in tariffs low, the value comes from using more of your own power through the day.
Check the inverter size
If you might add panels or a battery later, ask for an inverter with room to grow, or a hybrid inverter. Swapping the inverter later usually costs more than buying the right one now.
Common questions
The national average is $4,130 installed for a standard system and $4,890 for premium parts, after the STC discount and including GST, according to the Solar Choice Price Index for October 2026.
The Clean Energy Regulator deems about 11.4 kWh a day in Sydney, Brisbane, Adelaide, Perth and Canberra, and about 9.7 kWh a day in Melbourne and Hobart, averaged over a year.
It can be for a small household that is home in the day, but each watt costs more than a bigger system. If your roof has space, a 5 or 6.6 kW system usually gives a better return for not much more money.
Sources
System prices are from the Solar Choice Price Index, an industry average of installer quotes, as there is no government price series. Output and STC figures are from the Clean Energy Regulator. Last checked October 2026. Prices include GST unless we say otherwise.