Choose a country starting point
Choose from popular countries or all 54 African countries. The country page opens with local currency and Solar ROI assumptions.
🇳🇬 Nigeria selected - NGN
Select a country to prepare a solar ROI planning brief.
Review assumptions before opening the calculator
Nigeria country data: Medium confidence overall. Reviewed 2026-03-01; field confidence varies.
- Electricity tariff
- 68 NGN/kWhMedium confidence
- Generator fuel
- 700 NGN/litreMedium confidence
- Solar yield
- 5.5 peak sun hours/dayMedium confidence
- Install cost
- 725,000 NGN/kWLow confidence
Planning defaults for the country calculator. Replace them with a current bill, fuel receipt, site assessment, and written installer quote.
Tariff context: NERC and an AfroTools planning seed. Solar resource: Global Solar Atlas and an AfroTools country seed. Open solar resource source
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Plan the full solar decision
Use the country page first, then move to the specific calculator that answers your next question. For background reading, start with the generator vs solar guide.
Solar ROI FAQs
How do I calculate solar payback?
Enter your monthly grid bill, generator spend, outage hours, system size, battery choice, and financing assumptions. The calculator compares current energy spend with a solar scenario and estimates how long savings may take to recover the system cost.
Should I include generator fuel?
Yes, include generator fuel if you use a petrol or diesel generator for backup power. Generator savings can materially change payback, especially for shops, clinics, schools, churches, cold rooms, and SMEs with frequent outages.
Do I need a battery?
Not always. A battery is mainly for backup and night-time essential loads. Solar without a large battery can pay back faster, but it will not keep appliances running during outages.
What size solar system do I need?
Start from daily kWh, peak load, outage hours, and essential appliances. A small home may start around 1-2 kW, a family home around 3-5 kW, and businesses should do a load estimate before choosing a size.
Why is my payback different from installer quotes?
Quotes change with panel wattage, inverter brand, battery chemistry, usable battery capacity, roof work, protection devices, wiring distance, labour, warranty, maintenance, and finance charges.
What assumptions can I edit?
You can edit tariff, generator fuel price, solar yield, performance ratio, system size, install cost, battery cost, maintenance, deposit, interest, finance term, and outage or backup assumptions.
Is this a replacement for PVWatts or installer design?
No. Use this for early planning and quote comparison. PVWatts, PVGIS, Global Solar Atlas, and installer design tools can model location, roof, shading, inverter limits, and production more precisely.
How accurate is this calculator?
It is a planning estimate, not a quote. Accuracy improves when you use recent bills, real fuel receipts, a load profile, local solar yield, current equipment quotes, and finance terms from the provider.