Solar vs Generator in Nigeria: What Each Kilowatt-Hour Really Costs (2026)

Last month we put a generator and Band A grid electricity on the same scale and found the gap was four to seven times. Several readers asked the obvious follow-up: fine, but what does solar cost per unit, and how long before it pays for itself?

This is that answer. It is longer than "solar is cheaper," because the honest version has a condition attached.

The short answer

A petrol generator delivers electricity at roughly ₦1,000–₦1,300 per kWh at ₦1,250/litre — about ₦980 of that is fuel alone, with servicing and eventually replacing the machine on top.
Band A grid electricity is ₦209.50/kWh. Bands B through E are far cheaper, ₦31 to ₦69 depending on your DisCo.
Solar, levelised over ten years, lands around ₦170–₦210 per kWh for a typical Lagos household — competitive with Band A, and nowhere near competitive with Band E.
But cheaper per unit is not the same as worth buying, because solar asks for ten years of money on day one. Whether it pays back depends almost entirely on how many hours your generator currently runs.
For a household on Band D or E, break-even typically arrives in three to five years. For a Band A household with good supply and a generator that runs forty minutes a day, it may never arrive inside ten years.

Where the generator number comes from

The formula has not changed since our last piece:

Cost per kWh = (litres burned per hour × price per litre) ÷ kW actually delivered

What most comparisons get wrong is the denominator. Generators are rated in kVA but deliver kW, and at a power factor of about 0.8 a 3.5 kVA machine tops out near 2.8 kW. More importantly, the published fuel-consumption figures are quoted at about 75% load — so the litres you burn buy you 75% of that, roughly 2.1 kW, not 2.8.

Divide the fuel by the full nameplate rating instead and you will understate the cost by a quarter. That single slip is the most common reason published generator cost-per-kWh figures come out flatteringly low.

At ₦1,250/litre, a 3.5 kVA petrol set:

| Component | ₦/kWh | |---|---| | Fuel | ₦982 | | Servicing, oil, filters | ₦25 | | Replacing the machine | ₦89 | | Total | ₦1,096 |

The last line is the one nearly every comparison omits. A generator is a consumable. Petrol engines last roughly 3,000–5,000 running hours, and in Nigerian heat with 100–200-hour oil-change intervals, that is three to five years of real use. The money you will spend replacing it is a genuine cost of every unit it produces today.

And the smaller the machine, the worse the arithmetic gets. The 0.65–0.95 kVA sets — "I better pass my neighbour" — are the most expensive electricity most Nigerians will ever buy, well past ₦1,700 per kWh, because they burn almost as much fuel idling as working.

Where the solar number comes from

Solar has no fuel bill, so its cost per unit is the whole system divided by every kilowatt-hour it will ever produce:

Levelised cost = (system cost + battery replacements + cleaning and upkeep) ÷ lifetime kWh delivered

For a mid-size Lagos household using about 4.8 kWh a day, with a 1.4 kWp array, a 2.5 kVA hybrid inverter and a 5 kWh lithium battery, that comes to roughly ₦2.16 million in year one, plus about ₦680,000 of cleaning and minor upkeep over ten years, delivering about 16,700 kWh.

Call it ₦170 per kWh.

Two things about that figure are worth defending, because they are lower and higher respectively than what an installer will tell you.

Lifetime output is lower than the brochure. Standard solar models assume around 2% loss to dust. Nigerian measurements are brutal: research published in Renewable Energy recorded 68.6% yield loss over seventeen uncleaned months in the north, and the follow-up soiling map found the standard global dataset underestimates Nigerian soiling, with up to 88% optical loss measured on a horizontal test panel at Abuja. Panel degradation measured at Maiduguri runs 1.2–1.5% a year against a global norm of 0.5–0.8%.

So we model 74–78% system efficiency rather than the international 86%, and we put panel washing on the cost sheet — six visits a year in the south, twelve in the harmattan belt — instead of pretending it is free.

But the cost is real and complete. No installer's payback slide includes cleaning, and very few include the battery you will buy in year four if you choose the wrong chemistry.

The three numbers side by side

For that same Lagos household, on Ikeja Electric:

| Source | ₦/kWh | |---|---| | Grid, Band C | ₦46 | | Grid, Band A | ₦209.50 | | Solar, lithium, ten-year levelised | ₦170 | | Petrol generator, 3.5 kVA | ₦1,096 |

The generator is not "a bit dearer." It is roughly six times Band A and twenty-four times Band C. That is the number worth sitting with.

Notice also what this table implies about the grid. If you are on Band C at ₦46/kWh, solar cannot beat your tariff and is not trying to — it is competing with the generator hours, not with the grid units. This is why the payback question is really a question about your band.

Why cheaper per unit still might not mean buy

Here is the part the vendor calculators skip.

Solar only saves you money on the electricity it actually displaces. If your grid supply is good and your generator barely runs, there is very little expensive electricity for solar to replace — and you will have spent ₦2 million to displace ₦46/kWh grid units.

Running the same household through the model across all five bands, holding everything else constant:

| Band | Grid hours/day | Break-even | Ten-year position | |---|---|---|---| | A | 20 | Never inside 10 years | ₦265,000 worse off | | B | 18 | Never inside 10 years | ₦1.96m worse off | | C | 14 | Month 98 | ₦600,000 better off | | D | 10 | Month 54 | ₦3.27m better off | | E | 6 | Month 37 | ₦5.96m better off |

Band B looks worse than Band A, which surprises people. The reason is tariff, not supply: Band A customers pay ₦209.50 a unit and Band B customers pay around ₦62, so the Band A household has far more expensive grid electricity for solar to displace. Supply hours and tariff pull in opposite directions, and the result depends on both.

If you are a Band A or Band B customer with a generator that runs under an hour a day, the honest answer today is: don't buy yet. Nothing is wrong with the technology. The arithmetic simply is not there for you at ₦1,250 petrol, and it will change if fuel rises.

The fuel price problem

Every number above rests on ₦1,250 a litre, and that is the shakiest assumption in the whole exercise.

The NBS national average for petrol went ₦1,034.76 in January 2026, to ₦1,288.54 in March after the Hormuz closure, to ₦1,532.93 in April, to ₦1,596.25 in May, and back to about ₦1,250 by August. That is a 55% swing inside eight months. Diesel was worse: ₦1,420 in February, ₦3,277 in May, roughly ₦1,700 in August.

So a single payback number is close to meaningless. For that Lagos household on Band C, break-even lands at:

Month 117 if petrol falls to ₦875
Month 98 at today's ₦1,250
Month 61 if petrol rises to ₦1,625

Cheap fuel is the enemy of solar payback, which is a strange sentence until you remember that the generator is what solar is competing against.

What to do with this

If you are going to get quotes, three questions will tell you more than any brochure:

How many kilowatt-hours of battery is in this price? Not kVA — kWh. This is more than half the bill and it is the single reason two "5 kVA systems" can differ fivefold in price.
Lithium or tubular, and what is the warranty in years? The tubular bank that looks half the price usually costs more over ten years, for reasons we work through separately.
What daily output are you assuming, and does it allow for dust? If the answer implies better than about 78% system efficiency in the south or 74% in the north, it is optimistic for Nigeria.

You can run your own numbers — your appliances, your band, your generator, your pump price — in our solar payback calculator. It will tell you not to buy when the arithmetic says not to.

A note on our sources

Everything about the grid comes from NERC's published tariff orders, the same data behind our electricity bill calculator. Fuel prices come from NBS and from August 2026 Dangote and depot pricing.

The solar prices are the weak link, and we would rather say so than dress it up. No Nigerian public body publishes a residential solar price index. Every hardware figure we use traces to somebody who sells solar hardware. We handle that by pricing per component rather than per system, anchoring on two itemised real installation quotes rather than on the 2026 "price guide" blogs, stamping every figure with the month it was checked, and making all of it editable in the calculator. It is the best available, and it is not the same thing as a primary source.

The figure we are least happy with is the cost of replacing a generator, which feeds that ₦89/kWh line above. No citable Nigerian generator price table appears to exist, so that one is an informed placeholder rather than a sourced price — which is why the calculator lets you type in your own.