1Start from a typical building
2Your appliances
Edit the numbers to match your building. Use the power rating on each appliance's label. For fridges and freezers, about 10 hours a day is typical, because the compressor switches on and off.
| Appliance | Watts each | Qty | Hours / day | Remove |
|---|
3Your goals
How the planner calculates
- Peak load assumes everything in the list can run at the same time. This is the safe, worst-case figure.
- Inverter: peak load plus 25% headroom, and enough surge capacity for your largest motor (pump, fridge, AC) to start, at about 3 times its running power. Rounded up to a standard size.
- Battery: energy each appliance uses during the outage (up to its daily hours), divided by 92% inverter efficiency and 90% usable depth of discharge for lithium (LiFePO₄). Shown in 5.12 kWh modules, a common 48 V size.
- Solar: daily energy divided by peak sun hours (4.5 for Rwanda, 5.0 for Uganda) and a 75% system efficiency for heat, dust, wiring and battery losses. Shown in 550 W panels.
- Generator: peak load plus 25% headroom at 0.8 power factor, checked against motor starting, then rounded up to a standard kVA size. Fuel use follows a standard diesel fuel curve (0.08 L/h per rated kW plus 0.25 L per kWh produced) at the average outage load.