Local projects
Create, save, and reopen sizing projects directly on the device.
Android utility
IsolaWatt Solar Sizer
A simple offline calculator for preliminary off-grid solar sizing. It helps estimate battery capacity, PV array size, inverter minimum, and charge controller current from local project inputs.
Local project
Offline
Battery
Wh / Ah
PV array
Wp
Controller
A
Inverter
W
Runs on-device. No account, ads, analytics, or remote backend in the current release.
What It Does
IsolaWatt is built for quick estimates and field planning, not final engineering certification.
Load-based sizing
Enter appliance quantity, watts, and daily hours to estimate demand.
Transparent method
Review the formulas and assumptions used by the app before relying on results.