Solar Choice Solar & Battery Storage Sizing & Payback Calculator

solar_choice_logo_finalsolar_choice_logo_finalWith demand for solar battery storage in Australia growing quickly, Solar Choice has developed the below Solar PV & Battery Storage Sizing & Payback Estimator tool below to help Australian households & businesses to make a decision about whether to install a solar PV system, a battery storage system or both.

However, it’s important to keep in mind that all calculator outputs are indicative only. They are not intended to take the place of advice from an industry professional based on a more detailed assessment.

While we’ve made every effort to make sure that this calculator is as accurate as possible (given its inherent limitations), but there may still be some glitches that have slipped through the cracks – let us know.

If you’d like a more detailed assessment of your property’s solar potential, get in touch with Solar Choice via email, or fill out our Solar Quote Comparison Request form.

Looking for a more detailed analysis?

Additionally, Solar Choice’s commercial solar engineering team has a highly sophisticated solar & battery return on investment modelling tool for our internal use. If you are a commercial client who is thinking about investing in solar and batteries for your business, please reach out to us directly for a more accurate indicative business case. Matt Lasauce is our Commercial Tender Manager – he can be contacted on

Some notes about using this estimator:

1. This calculator has the following limitations

  • All financial calculations should be seen as indicative only. Outputs do not constitute recommendations or advice. Again, we recommend that you check the results from our calculator against those from other sources.
  • Solar in this tool is based on 365 days of historic solar irradiation data from the Bureau of Meteorology (BoM). These figures are averages from several years past and are therefore not predictors of future performance; the data is nevertheless useful in working out how a solar-plus-battery system will operate through different types of weather.
  • Household energy consumption data is based on rough consumption curves (read more here), repeated throughout the year. While users can select separate indicative curves for weekdays and weekends, extreme or unusual consumption events (such as having guests over for multiple days) cannot be modelled.
  • Due to file size limitations, the calculator only works for Australia’s capital cities at a limited range of tilt angles and orientations. We will look to improve the calculator (or add more, separate calculators) in the future.

2. Enter values into the white boxes (only!) 

Depending on your web browser, when you click on the calculator you will automatically jump to the top of the screen.

After you first click onto the calculator, use your keyboard arrows to move between boxes. The box you are currently editing will be highlighted.

This tool is designed to give you a set of outputs based on the details that you include. Changing the values in any of the coloured boxes may disrupt the formulas; if you do this by accident, simply refresh the page in your browser to start over.

The output values will change automatically as you enter your details in the white boxes – no need to hit any ‘submit’ buttons.

If you want to start over for any reason, simply refresh the page.

3. Try different combinations of sizes, prices and specifications

Our calculator is not designed just to spit out one set of answers, but rather to allow you to explore a range of possibilities and how they pan out. You’ll need to provide inputs of your own to make it relevant to you.

Below we’ve listed some resources for you to use to collect these inputs – otherwise you can just estimate them.

Energy usage & pricing

  • Your energy bill is the best place to get your energy usage & price data – there should be a chart on the back that shows your historic energy consumption by month.
  • The federal government’s EnergyMadeEasy website is a great place to compare energy pricing offers from suppliers in your area

Solar PV system & battery pricing

Compare Solar & Battery Quotes

  • There is not currently a reliable, publicly available, ‘one-stop’ source for battery pricing data in Australia. In addition to solar system prices, you can also compare battery storage system pricing by requesting a Solar Quote Comparison by filling out the form on this page.
  • Ball-park figures for a fully installed battery storage system are $800-$2,000 per kilowatt-hour (kWh) for lithium-ion and $500-$1,000 for lead acid.

Comments or feedback about this calculator?

We’d love to hear from you. Email us at

Choose the version of the calculator that best suits your situation

Full version of the solar & storage tool

This is the newest, most complete version of our solar & battery tool, updated in July 2017. It will allow you to generate rough, indicative financial outcomes for grid-connected solar PV, solar-plus-storage and battery retrofit scenarios. We are still ironing out bugs and making improvements, so please bear with us.

(Alternatively, you can  visit the older, archived version of this calculator or check out the ‘advanced’ version – also old.)

Battery retrofit tool (old version)

This tool allows you to get an idea of how much battery storage it might be beneficial to add to a pre-existing solar PV system. (Note that most people who add batteries also add solar – see some case studies here.)

New version of this tool coming soon – sign up for our newsletter to get updates.

Off-grid calculator (old version)

This tool allows you to work out (very roughly) how much solar & storage might be required for you to take your home off the grid. It does not include financial analysis.

New version of this tool coming soon – sign up for our newsletter to get updates.

Solar PV system payback calculator

Our oldest and most-used calculator tool, this calculator allows you to determine at a glance whether solar might be worth it for your home or business.

Simple solar system sizing estimator

This simple tool allows you to get a rough idea what size solar system your home is likely to benefit from most (keeping in mind that most people go with a 5kW solar system these days). This tool has no financial component.

Solar Choice’s Battery Storage Sizing & Payback Estimator