The True Cost of Generator vs Solar in Lagos

If your generator runs about 8 hours a day, a solar system sized for a how many solar panels do i need for a 3 bedroom flat in nigeria? load pays for itself in roughly 1.0–1.8 years of fuel it no longer buys. Run it more and that number falls; run it less and it rises — the table further down works both directions from your own generator's hours.

What running the generator actually costs

A 3kVA petrol generator at roughly half load burns 1.5–2 litres an hour (Lenol — cost of running a generator in Nigeria). Petrol is ₦1,100–₦1,500 a litre nationally (GlobalPetrolPrices / FuelTracker.ng, September 2026) — Lagos pump prices move with the national price, not against it, so the same range applies. Multiply the two together and the daily fuel bill depends entirely on how many hours the set runs:

Fuel only — no oil, no servicing, no repairs, no cost of the generator itself. Those are real money and we explain below why we have left them out rather than guessed at them.

The one number that decides your own answer

8 hours a day is our stated assumption, used everywhere on this site a generator figure is needed — it is not a measurement of your street, because supply varies too much between streets for a national figure to mean anything. If your set runs on the school run and the evening only, use the 4h row above. If NEPA barely shows up where you are, use the 16h row. Either way, the arithmetic is the same one used for the ₦8,663,436 system below — only the hours change.

What solar costs instead

The comparison needs one real system, not a range, so here is the Standard build for a how many solar panels do i need for a 3 bedroom flat in nigeria? load — 4.3kW if everything runs at once, 15.8kWh across a normal day.

Range ₦6.53M – ₦12.1M. Equipment priced from Nigerian vendor listings, last checked October 2026. Quote SB-8K-MTQ55T. Full working on the sizing page for this load.

Payback, at your generator's real hours

Same ₦8,663,436 system, set against each of the four generator-hours rows above:

The view over years, not months

Fuel is a cost you keep paying. Solar is a cost you pay once. At our 8h/day assumption, here is what each side has cost by a given year — generator fuel accumulating, solar flat because it was paid at installation:

Generator column is fuel only, held at the 8h/day assumption throughout — recompute it yourself from the first table if your hours differ. Solar column assumes no battery replacement in the window shown; see the caveat below for why that is a reasonable assumption at ten years and not beyond it.

What this leaves out, on purpose

• •Oil changes, servicing and repairs. A generator needs all three, and none of them has a reliable national naira figure we could cite — quotes for a service call vary by mechanic and by city far more than fuel does. Add your own from your own receipts; whatever it is, it only widens the gap in this page’s favour.
• •The generator itself, and eventually replacing it. Most households keep the set for the week solar and grid both fail. That is sensible, and it means the purchase price is not a saving you can bank — only the fuel it stops burning is.
• •Battery replacement. Lithium LiFePO4, which is what the Standard build above uses, is the one battery chemistry where a ten-year assumption is defensible — which is why the cumulative table stops there. The full replacement arithmetic, including the tubular-lead-acid case where it is not defensible, is worked out in lithium vs tubular batteries
• •Panel degradation and harmattan soiling. Both reduce output slightly and are covered on their own pages rather than folded into a payback number here — folding them in would need a cleaning schedule we do not know you will keep.

What a generator costs you besides naira

Some of the difference does not show up in any table. Solar is silent and has no fumes to stand near while it runs; it does not need a fuel queue or a padlocked tank; and it comes on the instant the grid drops rather than however long it takes to walk outside and pull the cord. None of that has a naira figure we can defend, so we are naming it in prose instead of pretending it belongs in the arithmetic above.

Run it on your own hours

The two inputs that matter are yours, not ours: how many hours your generator actually runs, and what appliances you actually want solar to carry. Get the second from the calculator, then apply your own hours to the fuel formula above. For the fuller three-case payback — generator, grid, or both, which is what most Nigerian homes actually pay — see is solar worth it in Nigeria. If part of what you are running is a stable grid connection rather than a generator, the tariff side of the sum is in your Band A bill versus solar. And if the number above is more than you want to spend at once, see what smaller budgets actually buy.