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.]

rooftop solarSolar 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. Read the full article →

James Martin II

James Martin II

Communications Manager at Solar Choice
James has been Solar Choice's primary writer & researcher since 2010. He lives in Newcastle in a house with a weird solar system.
James Martin II

{ 4 comments }

sinikk pollari 5 May, 2017 at 10:29 am

Can you tell me when new back up batteries ( new technology) will be available and when the government will subside there batteries .
I have 5 ks system Thank You

Solar Choice Staff 15 May, 2017 at 9:52 am

Hi Sinikk. Backup power is already possible with the right battery setup. As for a government subsidy, a few small jurisdictions (ACT and City of Adelaide) offer battery incentives, but there is nothing on the federal level.

Hope this helps!

Patrick Comerford 28 April, 2017 at 11:16 pm

These tables are all well and good but when determining the economic criteria it falls apart because of the current huge disparity in costs between different battery storage makes. A Powerwall 2 with a stated capacity of 13.5 kWh and a cost of say $12000 installed compared to a Sonnen 6kwh with a installed cost of $12000 it’s a no brainer whatever else is variable i.e. Size of PV system home consumption or usage patterns. Even if you don’t use the full capacity of the PW2 battery it still represents better value and you don’t need a complicated chart to tell you that. Or am I missing something?

Solar Choice Staff 1 May, 2017 at 12:00 pm

Hi Patrick,

Thanks always for your thoughtful input. You are well on point with this observation. We’ve written lots of articles on the financial case for solar & batteries and regularly point out (e.g. here) that – for now – solar makes more sense on its own. We’ve also pointed out that smaller battery banks tend to have faster payback periods than larger ones for the majority of homes. Our calculators yield the same results as well.

The focus of this article is sizing, with the aim of educating people about how large a battery bank they can actually make use of – giving them a starting point for shopping around. This will help people to avoid being oversold on system size, especially in instances when the bigger battery bank does indeed cost significantly more than the smaller one. If the larger battery bank is more cost-effective and can operate at partial states of charge (so that it’s not a problem if it doesn’t reach ‘full’ most of the time – if ever), then by all means the larger one would be the smarter choice – and leaves room for expansion.

As you’ve pointed out there are some significant price disparities at present, but we expect these to even out as time goes on and the market matures. At that point in time, these tables will become even more relevant.

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