What size solar panel array do you need for your home? And if you’re considering battery storage, what size battery bank would be most appropriate? This article includes tables that provide an at-a-glance guide, as well as links to more comprehensive calculators.
[Note that this article was originally published in April 2017, but has been recently updated in 2019]
Solar system sizing table (no batteries)
If you’re considering solar panels for your home, you’ll get the most value from them by directly ‘self-consuming‘ the energy that they produce during the daylight hours. The simple reason for this is that using the solar yourself allows you to avoid purchasing expensive energy from the grid instead of earning only a small credit for sending it into the grid. This is a crucial fact about going solar in Australia today.
Your rate of self-consumption will depend on a few factors, including the amount of energy that you use on a daily basis, the pattern of your consumption throughout the day, and the size of the system that you install. We recommend that you aim to self-consume at least 30% of the energy that your solar system produces.
Bonus tip: You can increase your solar self-consumption ratio by running more of your devices during daylight hours – possibly manually, on timers or using a home energy management system.
The table below contains very rough solar self-consumption ratio estimates for a range of popular solar system sizes and energy consumption levels. If the cell is red, the system is probably too large (or better suited for having batteries). If the cell is green, the system size is likely have a favourable payback period (keeping in mind that the higher the percentage is, the better).
|Your daily energy consumption||Solar system size|
Remember: The table above is a highly generalised, indicative guide; it does not take into account your location or the tilt & orientation of your roof – not to consider system prices or financial details like payback period. If you’d like to take a more detailed look, use our Solar PV System Payback Estimator or our Simple Solar System Sizing Estimator.
Watch the explainer video
Solar & battery system sizing table
Using Sunwiz’s PVSell software, we’ve put together the below table to help shoppers choose the right system size for their needs. PVSell uses 365 days of weather data Please read the paragraphs below and remember that the table is a guide and a starting point only – we encourage you to do more research (and get more opinions) before deciding on a system size.
About solar & battery system sizing ▼
About solar batteries & energy goals ▼
A few caveats... ▼
The battery bank sizing calculator
The battery bank sizing table
Your daily energy consumption
Largest recommended battery size for…
|Solar system size|
|Maximising energy independence:||–||22kWh (3 days of energy autonomy)||35kWh (5 days of energy autonomy)||35kWh (5 days of energy autonomy)||35kWh (5 days of energy autonomy)|
|Maximising energy independence:||–||–||40kWh (3 days of energy autonomy)||65kWh (5 days of energy autonomy)||65kWh (5 days of energy autonomy)|
|Maximising energy independence:||–||–||–||55kWh (3 days of energy autonomy)||90kWh (5 days of energy autonomy)|
|Maximising energy independence:||–||–||–||23kWh (0.77 days of blackout protection)||70kWh (3 days of energy autonomy)|
|Maximising energy independence:||–||–||–||–||40kWh (1.5 days of blackout protection)|
|Maximising energy independence:||–||–||–||–||27kWh (0.7 days of blackout protection)|
Glossary for this table ▼
He is now the communications manager for energy technology startup SwitchDin, but remains an occasional contributor to the Solar Choice blog.
James lives in Newcastle in a house with a weird solar system.
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