Gridly
Battery Energy Savings Calculator
Estimate how many kWh of grid electricity your home battery will save each year, based on your solar generation, consumption pattern and battery capacity.
e.g. Powerwall 3 = 13.5 kWh, BYD HVM = 16.6 kWh
Tesla: 89% · Sungrow/BYD: 96–97%
From your inverter monitoring - daytime energy not used at home
Electricity used from grid after sunset - check your bill or meter
Days with enough solar to charge the battery (est. 280–320 in most AU cities)
Your Results
Usable energy per charge cycle
12.8 kWh
after round-trip efficiency losses
Annual grid energy avoided
3,840 kWh
replaced with stored solar
Battery covers nightly demand
-%
Solar captured annually
- kWh
Est. full charge cycles / yr
-
Calculator notes
- Battery can only store up to its capacity per day - excess solar still exports to grid.
- Battery can only discharge up to the night-time demand - excess charge carries over (or is lost if next day is also full).
- Round-trip efficiency applies to both charge and discharge, so 95% means you recover 95 kWh for every 100 kWh stored.
- Results are estimates. Actual savings depend on your solar system size, household load profile, and seasonal variation.