Solar Systems: Which Size Do You Need?
The right solar system size depends on:
- How much electricity you use each day.
- When you use electricity, especially during daylight hours.
- How much suitable roof space you have.
- Whether you plan to add a battery or EV.
- Your local network’s inverter and export limits.
- Your budget and payback expectations.
As a rule of thumb, many homes are better off installing as much good-quality solar as they can reasonably fit and afford, rather than going too small and needing an upgrade later.
Not sure where to start? Let’s look at some common system sizes:
Solar System Size Guides
- 3 kW solar systems – a small system for low-usage homes, granny flats or tight roofs. Less common now, but still useful in specific situations.
- 5 kW solar systems – once a very common residential size, but now usually considered small compared to modern 6.6 kW and 10 kW systems.
- 6 kW & 6.6 kW solar systems – a popular starting point for many Australian homes, especially where roof space or single-phase limits are a factor.
- 10 kW solar systems – a good fit for larger homes, higher daytime usage, batteries, pool pumps, ducted air conditioning or future EV charging.
- 13 kW solar systems – a larger residential system for homes with serious electricity use, enough roof space and the right network approval.
Other Solar System Guides
- Off-grid solar systems – for homes without a reliable grid connection.
- Solar battery systems – for storing excess solar and using more of your own power at night.
- Solar feed-in tariffs – for understanding how much you’ll get paid for exporting excess solar electricity to the grid.
- Solar system upgrades – for homes that already have solar but need more capacity.
- Grid connection rules – important to know if you’re planning a larger system.
Get Help Choosing a Solar System Size
A good installer should look at your usage, roof, location and local network rules before recommending a system size. If you want quotes from installers I trust, you can get up to 3 quotes here.