If you've ever asked "how many solar panels do I actually need?" — you're not alone. It's the number one question we get from Nigerian homeowners before they go solar. The good news is the calculation is simpler than you think. This guide walks you through it step by step.
Why Getting the Size Right Matters
Too few panels and your inverter won't charge your batteries fast enough — especially during the harmattan season when sunlight hours are reduced. Too many panels and you've spent money you didn't need to spend.
Getting the right size means maximum savings, a fully charged battery every single day, and a system that performs reliably for 25+ years without issues.
Key Insight
Nigerian homes that are correctly sized for solar typically eliminate 80–100% of their NEPA dependency and save between ₦15,000 – ₦90,000 every month depending on system size.
The 4-Step Calculation
Follow these four steps and you'll know exactly how many panels your home needs:
List Your Appliances & Wattage
Write down every appliance you want to power with solar and how many watts each one uses. The table below has all the common Nigerian household appliances.
Calculate Your Daily Energy (Wh/day)
Multiply each appliance's wattage by the number of hours you use it per day. Add them all up to get your total daily energy consumption in watt-hours.
Add 25% for System Losses
No solar system is 100% efficient. Wiring losses, inverter efficiency and battery charging typically reduce usable energy by 20–25%. Multiply your total by 1.25.
Divide by Peak Sun Hours & Panel Wattage
Nigeria receives 4.5–5.5 peak sun hours per day. Divide your adjusted energy need by peak sun hours and then by your panel wattage to get the number of panels.
Common Nigerian Appliance Wattage
Use this reference table to find the wattage of every appliance in your home:
| Appliance | Typical Wattage | Daily Use (Avg) | Wh/Day |
|---|---|---|---|
| Ceiling fan | 60W | 8 hrs | 480Wh |
| Standing fan | 45W | 8 hrs | 360Wh |
| LED bulb (10W) | 10W each | 6 hrs | 60Wh each |
| 32-inch LED TV | 50W | 5 hrs | 250Wh |
| 43-inch LED TV | 80W | 5 hrs | 400Wh |
| DSTV Decoder | 15W | 5 hrs | 75Wh |
| Phone charger | 10W each | 3 hrs | 30Wh each |
| Laptop | 65W | 4 hrs | 260Wh |
| Refrigerator | 150W | 24 hrs | 3,600Wh |
| Deep freezer | 200W | 24 hrs | 4,800Wh |
| 1HP Split AC unit | 750W | 8 hrs | 6,000Wh |
| 1.5HP Split AC unit | 1,200W | 8 hrs | 9,600Wh |
| Washing machine | 500W | 1 hr | 500Wh |
| Water pump | 750W | 1 hr | 750Wh |
| Microwave | 1,000W | 0.5 hrs | 500Wh |
⚠️ Highlighted rows show AC units — these are the biggest factor in system sizing
Worked Example — Typical Lagos 3-Bedroom Flat
Let's calculate for a standard 3-bedroom Lagos apartment with no AC, running on solar from 6pm to 6am (12 hours overnight) plus daytime use:
| Appliance | Watts | Hours/Day | Wh/Day |
|---|---|---|---|
| 3 ceiling fans | 180W | 8 hrs | 1,440Wh |
| 6 LED bulbs | 60W | 6 hrs | 360Wh |
| 43-inch TV | 80W | 5 hrs | 400Wh |
| DSTV Decoder | 15W | 5 hrs | 75Wh |
| Refrigerator | 150W | 24 hrs | 3,600Wh |
| 4 phone chargers | 40W | 3 hrs | 120Wh |
| Laptop | 65W | 4 hrs | 260Wh |
| Total | 6,255Wh/day |
Now apply the formula:
Result: This home needs 5 × 400W panels
A 5-panel, 2kW system with a 3kVA hybrid inverter and 200Ah lithium battery will comfortably power this home 24 hours with no NEPA dependency.
Quick Reference — Panels by Home Type
Not sure about your exact appliances? Use this quick reference guide based on Nigerian home types:
1-Bedroom Flat
2-Bedroom (No AC)
3-Bedroom (No AC)
3-Bedroom + 1 AC
4-Bed Duplex + 2 AC
Shop / Small Office
What Inverter and Battery Do You Need?
Solar panels generate power during the day. To use electricity at night or during cloudy periods, you need a battery to store that energy and an inverter to convert it to usable AC power.
| Number of Panels | Inverter Size | Battery Recommended | Est. Budget |
|---|---|---|---|
| 2–3 panels | 1–2kVA Hybrid | 100Ah Lithium | ₦180k – ₦280k |
| 4–6 panels | 3kVA Hybrid | 200Ah Lithium | ₦350k – ₦520k |
| 7–10 panels | 5kVA Hybrid | 400Ah Lithium Bank | ₦650k – ₦950k |
| 11–16 panels | 10kVA Hybrid | 800Ah Lithium Bank | ₦1.2M – ₦1.8M |
Important: Always Choose Lithium Over Lead-Acid
Lithium LiFePO4 batteries last 6,000+ cycles compared to 300–500 cycles for lead-acid. In Nigeria's heat, lead-acid batteries degrade even faster. The upfront cost difference pays back within 18–24 months in replacement costs alone.
The AC Unit Factor
Air conditioners are the single biggest variable in solar sizing. A single 1.5HP AC unit running 8 hours a day adds approximately 9.6 kWh to your daily energy need — effectively doubling the size of the system required for a typical 3-bedroom flat.
If you plan to run AC on solar, budget for at least 8–10 panels per AC unit and ensure your inverter is rated to handle the startup surge current, which is typically 3–5× the running wattage.
Pro Tip — Use Inverter AC Units
Inverter-type air conditioners (like Hisense, LG Dual Cool, or Midea inverter models) use 30–50% less electricity than standard ACs. If you're going solar and want to run AC, switching to an inverter AC unit significantly reduces the number of panels you need.
Don't Want to Do the Maths Yourself?
Our solar engineers will calculate the exact system you need for free — just answer 5 quick questions. Get your personalised recommendation in 60 seconds.
Summary — Key Takeaways
- Calculate your daily energy need by multiplying each appliance's wattage by hours used
- Add 25% buffer for system losses and multiply by 1.25
- Divide by Nigeria's average 4.5–5 peak sun hours and your panel wattage
- Most Lagos 3-bedroom flats without AC need 4–6 panels of 400W each
- Each AC unit adds approximately 8–10 extra panels to your requirement
- Always pair your panels with a correctly sized hybrid inverter and lithium battery
- When in doubt, get a free expert calculation — it takes 60 seconds