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Sunulator is a free tool which estimates the economic feasibility of a solar system. Sunulator has been developed by the Alternative Technology Association (ATA).

The Sunulator currently covers NSW and Vic.


Sunulator is a simulation tool that can help you plan a grid-connected solar project.

Unlike most other solar calculators, Sunulator uses half-hourly consumption data over a whole year to estimate how much solar generation will be consumed onsite versus exported. Based on electricity tariff information, it then calculates the impact on your electricity bill and projects the savings over a 30-year timeframe. Financial results include payback period, net present value and Return on Investment.


Sunulator allows you to compare the results for several scenarios, for example different system sizes or panel orientations.

Community Investment Options

In Australia, most solar installations are owned directly by the electricity consumer, eg a home owner. Sunulator is designed to assist community organisations to install solar systems via additional investment options:

  • Community organisation installs a system and sells electricity to the host site.
  • Solar system installed via a loan from a community organisation.
  • Community organisation acts as an electricity retailer.
    Economic returns are estimated both for investors and the host site.

Requirements to use Sunulator

  • some experience using spreadsheets
  • some knowledge of electricity bills / data, eg:
    • what’s a tariff
    • kW vs kWh
    • Microsoft Excel, version 2003 or greater
    • system permissions to run macros

More information

Download the Sunulator.

Developing a solar project