6.6 kW became a familiar residential solar size in Australia because it pairs neatly with common inverter and oversizing arrangements, but whether it is right for a particular home depends on current and future electricity use.
How many panels make 6.6kW?
Modern panel ratings are higher than they were when 6.6 kW systems first became common, so the panel count varies:
| Panel rating | Approximate panel count |
|---|---|
| 400 W | 17 panels = 6.8 kW |
| 440 W | 15 panels = 6.6 kW |
| 475 W | 14 panels = 6.65 kW |
Use the Solar Panel Calculator for your chosen panel model.
How much does a 6.6kW system generate?
There is no single national answer. Melbourne, Sydney, Brisbane, Adelaide, Perth and other locations have different typical solar resources. Roof direction, shading and equipment losses also change real output.
Calculate indicative output for your location →
Is 6.6kW enough for a family home?
It may be, but electrification is increasing household demand. EV charging, heat-pump hot water, electric space heating/cooling, pool equipment and batteries can all change the optimum solar size. If roof and network limits allow, installing more solar now can sometimes be more economical than expanding later.
What determines savings?
The key question is not only how much the system generates, but how the generation aligns with household demand. Solar used directly avoids the retail import price, while exported energy receives the feed-in tariff.
Test your usage with the Solar Savings Calculator.
6.6kW solar with battery storage
A battery may increase self-consumption, but storage should be sized to surplus solar and evening/night demand. Do not assume a battery needs to be the same numerical size as the solar array.
Use the Battery Size Calculator for a first estimate.