Solar calculator
How the calculator works
Energy use
Each appliance’s watts multiplied by its hours of use, added up for a day.
Inverter size
The most power you could use at once, plus the start-up surge of the largest motor, with headroom, rounded up to a standard inverter size.
Battery storage
The energy you use after dark, divided by how much of the battery can be safely used. Lithium batteries let you use more of their capacity than tubular ones.
Solar panels
Enough panels to supply your daily energy on an average day, after allowing for heat, dust and wiring losses.
Savings
Your current grid and generator spend, and the share of it a correctly sized system typically replaces, shown as a range.
Want to check the sums yourself? Read our home solar sizing guide.
