Solar Calculator

How it works

Solar power reduces your bills in two ways:

  • Self Consumption

    When your home is using solar energy instead of the grid.

  • Exporting surplus solar

    for a ‘feed-in tariff’

  • Total savings

    This calculator adds these to find your total savings

  • Add a battery

    Adding a battery increases self-consumption by using stored solar energy at night, reducing your power bills even further. But batteries will also extend your payback time.


These calculators are intended to provide illustrative examples based on stated assumptions and your inputs.

Although we’ve tried hard to get all the calculations correct – there is a possibility that we’ve made a mistake somewhere – we are only human.

Beware that – although the default settings change by state/territory to reflect sensible values – the default settings of the solar calculator will most likely not be applicable to your situation, and you should ensure you change all the inputs to reflect your own circumstances.

You should also check that the Feed In Tariff settings are correct for your retailer (although don’t forget you can change retailers and the default setting is the best FiT available in your state at the time of writing).

Changing any of the inputs can have a large impact on the solar calculator’s outputs. It is particularly difficult to estimate the % of energy you will self consume, so you should try the calculator with a range of scenarios, e.g. 10% self-consumption, 50% self-consumption, etc, to ensure you understand the consequences of exporting more or less electricity as your usage patterns change.

Also, no one knows what the feed in tariff rates will be in the years ahead. You should always model the effect of a 0c FiT as a worst case scenario.

Calculations are meant as estimates only and are not intended to be kept or used for any practical purpose. They are based on information from sources believed to be reliable and accurate and are not intended to be used as a substitute for professional advice.

The calculators are not intended to be solely relied on for the purposes of making a decision in relation to a solar power product or finance deal.

Consumers should consider obtaining advice from an Australian Financial Services licensee before making any financial decision regarding mortgages, loans or solar financing.

Actual outcomes will depend on a range of factors outside the control of Solar Galaxy.

A note about the seasonal bill estimates:

This calculator cannot provide an exact prediction of your quarterly post-solar-bills because it does not know:

a) the seasonal variation in your electricity bills – we ask you for your daily consumption – then use typical seasonal variation (using thousands of data-sets kindly provided by Solar Analytics) to estimate how that bill will vary with each season.

b) your energy usage profile through each day. We would need to know this to know your self consumption ratio each day to five really exact predictions. To counter this – we allow you to change your self-consumption – then estimate how that would vary by seasonal, then use that to calculate the solar savings.