PVOUT (specific photovoltaic power output) is the electricity a 1 kWp array produces per day, in kWh, after typical losses (temperature, soiling, wiring, inverter, availability), for a fixed array at optimum tilt. It is the number to use for sizing. GHI (global horizontal irradiation, kWh/m²/day) is the raw sunlight on a flat surface and is what "peak sun hours" loosely means; using it directly overstates output by 15–25%.
| City | PVOUT, avg | Worst month | Best month | Per year | GHI | Opt. tilt | Air temp |
|---|---|---|---|---|---|---|---|
| JosNorth Central · 9.90, 8.86 | 4.71 | 3.63 | 5.61 | 1.717 kWh/kWp | 5.81 kWh/m² | 15° | 21.9 °C |
| MaiduguriNorth East · 11.85, 13.16 | 4.69 | 3.95 | 5.30 | 1.712 kWh/kWp | 5.90 kWh/m² | 16° | 27.9 °C |
| KanoNorth West · 12.00, 8.52 | 4.65 | 4.00 | 5.16 | 1.699 kWh/kWp | 5.82 kWh/m² | 16° | 26.3 °C |
| SokotoNorth West · 13.06, 5.24 | 4.62 | 3.95 | 5.05 | 1.685 kWh/kWp | 5.82 kWh/m² | 17° | 28.9 °C |
| KadunaNorth West · 10.52, 7.44 | 4.45 | 3.45 | 5.22 | 1.626 kWh/kWp | 5.54 kWh/m² | 15° | 25.1 °C |
| AbujaNorth Central · 9.06, 7.49 | 4.13 | 3.15 | 5.00 | 1.507 kWh/kWp | 5.17 kWh/m² | 13° | 26.6 °C |
| OnitshaSouth East · 6.15, 6.79 | 3.86 | 3.32 | 4.32 | 1.407 kWh/kWp | 4.84 kWh/m² | 7° | 26.8 °C |
| EnuguSouth East · 6.45, 7.51 | 3.80 | 3.20 | 4.42 | 1.386 kWh/kWp | 4.78 kWh/m² | 9° | 26.8 °C |
| IbadanSouth West · 7.38, 3.95 | 3.65 | 2.83 | 4.24 | 1.333 kWh/kWp | 4.57 kWh/m² | 9° | 25.9 °C |
| OwerriSouth East · 5.48, 7.03 | 3.64 | 3.12 | 4.05 | 1.328 kWh/kWp | 4.57 kWh/m² | 7° | 26.1 °C |
| LagosSouth West · 6.52, 3.38 | 3.63 | 3.15 | 3.96 | 1.323 kWh/kWp | 4.54 kWh/m² | 7° | 26.6 °C |
| Benin CitySouth South · 6.34, 5.63 | 3.61 | 3.07 | 4.01 | 1.319 kWh/kWp | 4.52 kWh/m² | 7° | 25.8 °C |
| CalabarSouth South · 4.96, 8.33 | 3.61 | 2.94 | 4.14 | 1.317 kWh/kWp | 4.51 kWh/m² | 7° | 25.8 °C |
| Port HarcourtSouth South · 4.82, 7.03 | 3.43 | 2.88 | 3.90 | 1.251 kWh/kWp | 4.29 kWh/m² | 6° | 26.0 °C |
Monthly profile
The annual average hides a seasonal swing of 20–30%. In the south the trough is the July–September rainy season; in the north it is August plus the Harmattan months when dust reduces direct sunlight.
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Jos | 5.50 | 5.48 | 5.12 | 4.48 | 4.16 | 3.97 | 3.69 | 3.63 | 4.31 | 5.00 | 5.61 | 5.57 |
| Maiduguri | 5.23 | 5.21 | 4.90 | 4.56 | 4.32 | 4.01 | 3.98 | 3.95 | 4.59 | 5.01 | 5.30 | 5.25 |
| Kano | 5.13 | 5.05 | 4.72 | 4.52 | 4.36 | 4.21 | 4.09 | 4.00 | 4.59 | 4.91 | 5.16 | 5.14 |
| Sokoto | 4.99 | 5.02 | 4.66 | 4.54 | 4.36 | 4.23 | 4.09 | 3.95 | 4.65 | 4.90 | 5.05 | 5.02 |
| Kaduna | 4.99 | 4.95 | 4.65 | 4.50 | 4.24 | 3.89 | 3.59 | 3.45 | 4.18 | 4.73 | 5.22 | 5.12 |
| Abuja | 4.61 | 4.60 | 4.42 | 4.17 | 3.90 | 3.55 | 3.28 | 3.15 | 3.74 | 4.33 | 5.00 | 4.83 |
| Onitsha | 3.90 | 3.95 | 3.90 | 4.00 | 3.94 | 3.64 | 3.32 | 3.33 | 3.72 | 4.03 | 4.32 | 4.21 |
| Enugu | 4.07 | 4.06 | 3.85 | 3.81 | 3.76 | 3.45 | 3.22 | 3.20 | 3.51 | 3.84 | 4.42 | 4.39 |
| Ibadan | 3.83 | 3.93 | 3.83 | 3.85 | 3.82 | 3.44 | 2.95 | 2.83 | 3.31 | 3.70 | 4.24 | 4.16 |
| Owerri | 3.80 | 3.82 | 3.67 | 3.80 | 3.72 | 3.38 | 3.12 | 3.24 | 3.50 | 3.64 | 3.94 | 4.05 |
| Lagos | 3.61 | 3.76 | 3.86 | 3.96 | 3.82 | 3.25 | 3.15 | 3.31 | 3.42 | 3.67 | 3.84 | 3.85 |
| Benin City | 3.69 | 3.73 | 3.69 | 3.82 | 3.74 | 3.43 | 3.07 | 3.18 | 3.40 | 3.64 | 4.01 | 3.99 |
| Calabar | 3.99 | 4.01 | 3.70 | 3.79 | 3.72 | 3.35 | 2.95 | 2.94 | 3.30 | 3.61 | 3.83 | 4.14 |
| Port Harcourt | 3.73 | 3.75 | 3.47 | 3.69 | 3.52 | 3.06 | 2.88 | 3.09 | 3.23 | 3.34 | 3.51 | 3.90 |
Worst month: the sizing number
A system that must carry a household every night has to be sized for the month it produces least, not the annual mean. For Lagos that is 3.15 kWh/kWp/day (Jul) against an average of 3.63; the array needs 15% more panels than an average-based design. In Kano the penalty is 16%.
| City | On average | On worst month | Extra panels |
|---|---|---|---|
| Lagos | 3.8 kWp · 7 panels | 4.4 kWp · 8 panels | 1 |
| Port Harcourt | 4.0 kWp · 8 panels | 4.8 kWp · 9 panels | 1 |
| Abuja | 3.3 kWp · 7 panels | 4.4 kWp · 8 panels | 1 |
| Kano | 3.0 kWp · 6 panels | 3.4 kWp · 7 panels | 1 |
Hybrid systems with a reliable grid or a generator for the wet season can size closer to the average and accept a few generator hours in August; off-grid systems cannot.
Optimum tilt and temperature
Optimum fixed tilt runs from 6° on the coast to 17° in the far north, roughly equal to latitude plus a small correction for the seasonal cloud pattern. Below 5° panels self-clean poorly; the loss from 5–15° instead of optimum is under 2%. Long-term mean air temperature is 22–29 °C; cell temperature at midday runs 25–35 °C above that, which the PVOUT model already deducts through the temperature coefficient.
How to use these numbers
PV_kWp = E_daily ÷ PVOUT_worst ÷ η_batt // array to cover a load through the worst month, with storage losses
Annual_kWh = PV_kWp × PVOUT_year // for economics; see solar vs generator
For a location not listed, query the Global Solar Atlas directly (method below) or take the nearest city in the same climate zone. The sizing calculator and panel count calculator carry these values built in.
Method and query
Values are the long-term averages returned by the Global Solar Atlas API for the city-centre coordinates listed, layer PVOUT_csi (PV output for a fixed, optimally tilted, small crystalline-silicon system with typical losses), together with GHI, DNI, optimum tilt (OPTA) and air temperature (TEMP). Monthly values are the monthly totals divided by days in the month. The endpoint, with Lagos as an example:
GET https://api.globalsolaratlas.info/data/lta?loc=6.52,3.38 → annual.data.PVOUT_csi = 1323 kWh/kWp (÷ 365 = 3.63) → monthly.data.PVOUT_csi = [3.61, 3.76, 3.86, 3.96, 3.82, 3.25, 3.15, 3.31, 3.42, 3.67, 3.84, 3.85] kWh/kWp/day (converted)
Data version 2.2.68, updated 1 April 2026, period to 2025; fetched 16 September 2026. The raw JSON for every city is archived with the site. Licence: CC BY 4.0; attribution: Global Solar Atlas 2.0, a free, web-based application developed and operated by Solargis s.r.o. on behalf of the World Bank Group, funded by ESMAP.
Coordinates are city centres; yield varies by a few percent across a metropolitan area and more where local haze (industrial Lagos, coastal fog) applies. Roof shading, orientation off optimum, soiling beyond the model's assumption and inverter clipping are not included: budget a further 5–15% for a real roof.
FAQ
How many peak sun hours does Nigeria get?
Expressed as PV yield, 3.43–4.71 kWh per kWp per day depending on city (Global Solar Atlas). Raw sunlight (GHI) is 4.29–5.81 kWh/m²/day; the difference is system losses. Quoting "5–6 peak sun hours" for Lagos overstates output by about a third.
Which part of Nigeria is best for solar?
The far north: Jos (high altitude), Maiduguri, Kano and Sokoto all exceed 4.6 kWh/kWp/day. The Niger Delta coast is lowest at 3.4–3.6. Solar is viable everywhere; the array just needs to be 25–35% larger on the coast for the same load.
What is the worst month for solar in Lagos?
Jul at 3.15 kWh/kWp/day, versus 3.96 in Apr. July to September average about 3.29.
Can I use these figures for a commercial roof?
Yes for a first estimate; PVOUT_csi assumes a small fixed system. Large ground-mounted or tracking systems perform differently, and a proper design should use hourly data from Solargis, PVGIS or Meteonorm with the actual layout.
Sources
- Global Solar Atlas 2.0 — Solargis, World Bank / ESMAP. API endpoint api.globalsolaratlas.info/data/lta; PVOUT_csi, GHI, DNI, OPTA, TEMP layers; data v2.2.68 updated 1 April 2026 — globalsolaratlas.info
- World Bank Data Catalog — Nigeria: Solar irradiation and PV power potential maps (Solargis), CC BY 4.0 — datacatalog.worldbank.org/dataset/nigeria-solar-irradiation-and-pv-power-potential-maps
- Global Solar Atlas methodology — Solargis PV simulation model (fixed-tilt, typical losses) — globalsolaratlas.info/support/methodology