Worked example
Solar & battery sizing for a fridge-only backup
The simplest case — keeping a single fridge running through outages, the most common starting point for backup power.
Open this fridge-only backup setup in the calculator →
Example daily load
| Device | Power | Use | Energy |
|---|---|---|---|
| Fridge | 120 W | 24 h/day | 2880 Wh |
| Total | 2880 Wh/day |
Sized system (LiFePO4, 12V, 1 day autonomy)
Battery bank
4.08 kWh
Capacity
340 Ah @ 12V
Solar array
928 W
Sun hours assumed
4.5 h/day
Open this setup in the calculator — then adjust for your own devices →
Notes for a fridge-only backup
These figures assume 4.5 peak sun hours and 1 day(s) of autonomy. If your location is cloudier, your usage is higher, or you want more buffer, increase autonomy or array size. The button above opens the full calculator pre-loaded with this fridge-only backup setup, so you can change any device, voltage or chemistry and see the system resize instantly — the example is a starting point, not a prescription.