Solar Battery Kilo-Watt Hour kWh Sizes | SunWatts
That means the average power required per day is 30 kWh. Now, when sizing a grid-tied solar battery system for daily usage, you will want a system that can deliver up to 30 kWh, or possibly more for peak usage days. However, if you also want the system to provide off-grid backup battery storage, then you will typically choose 3X to 5X the daily