What Size Solar System Should I Install?

What Size Solar System Should I Install?

When considering if solar is right for your home, one of the first questions you’ll need to ask yourself is what size system should I install?

If you are new to solar, working out power consumption, roof space and grid limits can seem daunting, but this article should help clear some of your confusion. If you would prefer to have one of our Qualified Renewable Energy Installers calculate this for you, just click here or read on for some further information…

What Size Solar System Should I Install on my Home?

  1. How much energy does my home use?The easiest way to work out your home’s daily energy usage is by checking your energy bill. Below is an example of an Origin Energy bill with a quarterly usage amount of 75kWh. This amount can be found in the ‘Your Usage Summary’ section.

Below is an approximate Energy Usage to Solar System Size example:

0-30kWh per day = 6.6kW Solar System

31-45kWh per day = 10kW Solar System

46kWh+ per day = 13.2kW Solar System


Most Australian homes fall into the 0-30kWh range; requiring only a ‘6.6kW’ Solar System.


  1. How many panels can my roof fit?

If you have a small or predominantly shady roof area, this can affect the size of your system. Most homes in Australia have between 100-200 m2 of roof space which can generally fit between 20-30 solar panels. This is usually suitable for an average-sized 6.6kW solar system. For a more detailed analysis of how many panels your roof can fit, speak to one of our Qualified Renewable Energy Installers for a custom review.

  1. What are the grid limits for my area?

When the electricity grid was first constructed, it was not designed to have energy flowing in both directions (import and export). To accommodate for the recent influx of solar energy now feeding into our grid, operators have introduced ‘grid limits’ to help balance the voltage and frequency of our existing pole and wire infrastructure.

In most parts of Australia, grid operators limit single-phase connection export capacity to 5kW and three-phase connection export capacity to 30kW. This limits the amount of ‘feed-in-tariff’ you are able to benefit from. If you are considering installing a large solar panel system to your rooftop, you can store the excess solar energy generated throughout the day for night-time use with a home energy storage or battery system. With now record low feed-in-tariff fees, many Australians are now choosing to store most of their energy for their personal evening usage.

Owning a home energy storage system had added benefits too, like black-out protection and energy independence. To learn more about home energy storage systems, click here to speak to one of our Qualified Renewable Energy Installers today!