How Many Solar Panels Do I Need to Power My Home?

"How many panels do I need?" is the first question every buyer asks — and the honest answer is: it depends on what you want to power. This post gives you the actual maths, worked examples for common Nigerian home sizes, and tips for sizing correctly so you don't under-buy or over-spend.

The Formula

Number of panels = Daily energy need (kWh) ÷ (Panel wattage (kW) × Peak Sun Hours × System Derate). Use 0.80 for the derate — it bundles inverter efficiency (~96%), wiring losses (~2%), and temperature/dust losses (~5%). Peak Sun Hours: Lagos/PH 4.2, Abuja 4.6, Kano/Sokoto 5.0.

Step 1 — Estimate Your Daily kWh

Refrigerator (200L frost-free): ~1.5 kWh/day
LED lighting (10 × 9W, 6 hrs): ~0.54 kWh/day
Ceiling fans (3 × 55W, 10 hrs): ~1.65 kWh/day
TV 43 inch (80W, 5 hrs): ~0.4 kWh/day
Water pump (0.75HP, 1 hr/day): ~0.56 kWh/day
Phone/laptop charging: ~0.3 kWh/day
1.5HP Inverter AC (1,100W, 6 hrs): ~6.6 kWh/day
SUBTOTAL without AC: ~5 kWh/day | with AC: ~11.6 kWh/day

Worked Examples

2-bedroom flat, Lagos, no AC, 8 kWh/day → 8 ÷ (0.5 × 4.2 × 0.8) = 4.8 → 5 × 500W panels (2.5 kWp).
3-bedroom bungalow, Abuja, one AC, 12 kWh/day → 12 ÷ (0.5 × 4.6 × 0.8) = 6.5 → 7 × 500W panels (3.5 kWp).
4-bedroom duplex, Kano, one AC + heavy load, 16 kWh/day → 16 ÷ (0.5 × 5.0 × 0.8) = 8.0 → 8 × 500W panels, or 6 × 665W panels (4.0 kWp either way).
Tip: Higher-wattage panels (620W–665W) mean fewer units on the roof for the same total power — better if roof space is limited.

Harmattan Dust — The Hidden Panel Thief

Between November and February, harmattan dust deposits on panel glass can reduce output by 15–25%. If you're sizing for year-round reliability, either add one extra panel to the array or commit to a monthly rinse. Our cleaning guide explains the safest way to clean panels without scratching the anti-reflective coating.

Panel Recommendations by Array Size

Small array (3–5 panels): Astronergy TOPCon N5 480W or Itel 410W — compact, easy to mount, lower upfront cost.
Medium array (5–8 panels): Jinko 590W N-Type Bifacial or Itel 590W — good balance of output and price.
Large array (8+ panels): Jinko 620W N-Type or Canadian Solar Hiku7 665W — fewest panels for maximum kWp.

Next Steps

Frequently asked questions

How many solar panels do I need to run an air conditioner in Nigeria?+

A 1.5HP inverter air conditioner running 6 hours a day consumes roughly 6.6 kWh. To cover just the AC in Lagos (4.2 PSH), you need about 3–4 × 500W panels dedicated to it. For a full home with one AC, budget 7–10 panels total depending on other loads.

Can I start with fewer panels and expand later?+

Yes — most hybrid inverters accept additional panels over time. It's best to install an inverter and battery sized for your end-goal array from day one, then add panels in phases. Mixing panel generations is possible but check with your installer that Voc and Isc are within the existing string's tolerance.

Does my location in Nigeria affect how many panels I need?+

Significantly. Kano receives roughly 5.0 peak sun hours versus Lagos at 4.2. A home in Kano can achieve the same daily kWh output with about 16% fewer panels compared to the same home in Lagos. Always use location-specific peak sun hour data when sizing your array.