E = capacity × DoD × efficiency. Runtime = E / average power. PV is a daily energy scenario only; it does not guarantee night or winter operation. Check starting currents and inverter power separately.
ZeroHouse
Home autonomy calculator
Transparent assumptions and a preliminary result.
Related
Autonomy
Knowledge: critical functions and outage scenarios.
Build an average-load scenario
Appliance fields use watts. A refrigerator's or pump's average demand over a period can differ from its running nameplate power. The tool adds the entries into a constant average load P. It does not simulate alternating operation, motor starting or brief peaks. First define the period and how the average values were obtained so the calculated duration has a clear meaning.
Convert stored energy into time
Usable energy E is capacity C multiplied by the allowed discharge fraction DoD and efficiency η. Percentages become fractions; runtime t = E/P is calculated with kWh and watts converted consistently. For example, an illustrative 2 kWh of usable energy at a steady 100 W gives 20 hours. This is an arithmetic example, not a rating for a particular battery or a promise about an installed system.
Read the solar input as a daily balance
Entered PV is daily energy used in a simplified deficit calculation. It does not guarantee charging at the required hour or automatically extend every overnight scenario. Weather, season, ageing, temperature and self-consumption beyond the chosen efficiency are not modelled separately. Save several load alternatives for discussion. Inverter power, protection and recharge between outages still need their own assessment; a plausible runtime result cannot establish that a demanding appliance will start successfully. Zero load does not yield a finite duration with this formula; first identify functions that will actually consume energy.