What Size Solar System Do I Need?

What Size Solar System Do I Need?

How to Choose the Size of Your Solar System

Generally there are two ways to sizing a rooftop solar system for your home.

  1. More the merrier
    Install as many panels as your roof and/ or budget will allow. You know solar is a good thing, and if you are going to get solar installed want to do it well. This method is more future proof, because if your family grows, you add a pool, own electric cars in the near future or intend to add a battery system in coming years, this larger system will be able to service it all. This is a great approach as long as you understand a few things, which we will discuss with you.
  2. Do some maths
    You want to maximise the financial return from your solar with a system sized to give you optimum return. Measuring this can be complex and it will depend on how much electricity you use, when you use that electricity and more. To keep it simple, here is a rough guide to help you see what system might be right for you. All you need to know is your current electricity bill and if you expect that to stay around that level of electricity use in the short to medium term future.


$200 or more per bill                3kw                              $120 – $200 per bill

$350 or more per bill                5kw                              $180 – $350 per bill

$500 or more per bill                8kw                              $300 – $500 per bill

$800 or more per bill                10kw                             $400 – $700 per bill

From our experience, the average solar system we install has an estimated payback period of between 2.5 – 4 years. Please note this and the chart above is as a rough guide only. A number of additional factors need to be considered, including the time of the day you use the majority of your energy, current or future shading, your roof design, weather patterns and your future circumstances.