Most Nigerian homeowners guess solar capacity. Here's how to calculate exactly what you need.
Step 1: List Your Appliances
| Appliance | Power (W) | Hours/Day | Daily kWh |
|---|---|---|---|
| Refrigerator | 800 | 24 | 19.2 |
| Lighting (8 LED bulbs @ 12W) | 96 | 8 | 0.77 |
| TV | 200 | 6 | 1.2 |
| Water Pump (1 hr/day) | 1500 | 1 | 1.5 |
| TOTAL DAILY | - | - | 22.67 kWh |
Step 2: Add 25% Buffer
Add 25% buffer for inefficiencies, cloudy days, and battery losses.
22.67 × 1.25 = 28.34 kWh daily requirement
Step 3: Calculate Solar Capacity
Nigeria receives 4-5 peak sun hours daily. Use 4.5 average:
28.34 ÷ 4.5 = 6.3kW solar capacity needed
System Sizing Summary
- Solar Panels: 6-7kW (15-16 panels @ 400W each)
- Battery Capacity: 10-15kWh (minimum 50% of daily usage)
- Inverter: 5-7kW (handle simultaneous loads)
- Estimated Cost: ₦3.2-₦4.0 million
Recommended System for Different Home Sizes
- 2-3 bedroom apartment: 3-4kW solar, 5-10kWh battery
- 4-5 bedroom house: 5-7kW solar, 10-15kWh battery
- 6+ bedroom mansion: 8-10kW solar, 15-25kWh battery
Don't Oversizing Waste Money?
Slightly oversizing (by 10-15%) is okay because it handles future expansion, provides surge protection, and maintains efficiency during system degradation. Major oversizing wastes capital.
Get a professional assessment for precise sizing.