Size Your Off-Grid System
Appliance By Appliance
Quick answer: every off-grid system is sized from two numbers — your potential load (the kW drawn if everything switched on at once, which sets the inverter) and your average daily consumption (the kWh you use in a day, which sets the array and battery bank). Tick the appliances you actually use below, adjust the hours, and you'll have both.
Start CalculatingTick what you run, and for how long.
Wattages are typical Australian figures to get you moving — every one is editable, so if you know the plate rating on your own appliance, put it in. Set the quantity and the hours you'd genuinely use it on an average day, then enter your details below to see your load profile.
Your own appliances
Enter your details to see your load profile.
What your system has to cope with.
Select at least one appliance above and your load profile will appear here.
Your load profile is ready
You've selected 0 appliances. Enter your details in Step 2 above and your potential load and average daily consumption will appear here — we'll send a copy through with them.
Enter my detailsThe power drawn if everything you ticked ran at the same moment. Your inverter has to be able to carry this — plus surge headroom for motors, pumps and welders that spike on start-up.
The energy you get through in a typical day. This is what the solar array has to generate and the battery bank has to store and give back overnight and through poor weather.
Where your power goes
Indicative only. Wattages shown are typical Australian appliance ratings and your own units will differ — check the compliance plate where you can. Fridges, freezers, air conditioners and heat pumps cycle rather than draw continuously, so their hours here represent run-time, not hours switched on. Motor-driven loads (pumps, compressors, welders, power tools) draw a starting surge well above their running wattage, which is accounted for in system design rather than in this figure. Seasonal swing matters too — heating and cooling loads in the Canberra, Queanbeyan and South Coast regions vary a great deal between winter and summer, so an average day is only ever an average.