Size of solar inverter dependent on the equipments that are intended to be used while utility supply is down. Total load on inverter is equal to the sum of all nameplate rating of such equipments. While sizing, some equipment like air conditioner and refrigerators should be sized at 2/3 times normal rating to account for the high inrush current drawn by these equipments while starting. An additional 25 -30 % can be considered as buffer for future expansion.

Once the total wattage of devices are calculated, the next step is to determine the type and number of batteries required to support your inverter. The battery capacity, measured in ampere-hours (Ah), is crucial for ensuring your system can store enough energy to meet your needs, especially during power outages or when solar input is unavailable.