The Alternative Technology Association (ATA) has launched a new, remodelled version of ‘Sunulator’, its free economic analysis tool for grid-connected solar PV systems. The simulation software has been upgraded to include an on-grid battery storage component and extended coverage across Australia.
Sunulator is a free simulation tool designed to help households, businesses and community groups plan a grid-connected solar project. It uses half-hourly consumption and generation data over a whole year to estimate how much solar generation will be consumed on-site versus exported.
For each half-hourly interval, the model simulates:
- solar generation based on the sun’s position and weather data.
- battery charge/discharge and grid export/import.
- household cost or revenue based on relevant grid tariff.
Based on this information, the tool then calculates the impact of the system on a household’s electricity bill and projects the savings over a 30-year time frame.
This is important when considering battery storage, since – as experts have noted – it is far from simple to determine when it is economical to install storage, and what capacity of storage is appropriate.
he tool still has a few limitations. The ATA’s recent Household Storage Analysis report, which was based on analysis using the new version of Sunulator, noted that the Perth time of use tariff was too complex to model in the current version of the tool. The software currently does not provide modelling for oversized arrays, or for off-grid systems, and it also requires some proficiency in Microsoft Excel.
Nonetheless, Sunulator appears to be a valuable tool for households looking to install solar and/or storage. And for installers, it could be a handy way of helping customers understand the economic and environmental benefits of installing a system, especially as feed-in tariffs tail off and battery storage technology becomes more widespread.
