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Solar & Inverter Size Calculator
Add up your appliances, choose how many hours of backup you want, and get a recommended inverter, battery bank and panel count.
1. Your load
| Appliance | Watts | Qty | Hrs/day |
|---|
2. System settings
How we size your solar system
- Inverter: peak load × 1.25 safety margin, divided by a 0.8 power factor, rounded up to the next common size (1, 1.5, 2.5, 3.5, 5, 7.5, 10, 12, 15 kVA).
- Battery: the share of daily energy used from the battery, divided by depth of discharge (90% for lithium, 50% for lead-acid) and 90% inverter efficiency.
- Panels: daily energy ÷ (peak sun hours × 0.75 to allow for heat, dust and wiring losses), divided by panel wattage.
Treat the result as a planning estimate. A qualified installer should confirm the design, cable sizes, charge controller/MPPT rating and protection devices before you buy.
Frequently asked questions
What size inverter do I need for a 3-bedroom flat in Nigeria?
A typical 3-bedroom flat running lights, fans, TV, fridge, freezer and laptops (without AC) needs about a 3.5–5 kVA inverter. Adding one 1.5HP inverter AC usually pushes it to 5–7.5 kVA.
Lithium or tubular batteries?
Lithium (LiFePO4) costs more upfront but can be discharged to about 90%, lasts 6,000+ cycles and needs no maintenance. Tubular lead-acid batteries are cheaper but should only be discharged to about 50%.
How many solar panels do I need for a 5kVA inverter?
It depends on daily energy use, not inverter size. Homes using 10–12 kWh a day typically need eight to ten 550W panels in most of Nigeria.