Lagos State

Rooftop solar in Lagos Island, Lagos: what the roofs are worth

Lagos Island has 12,001 buildings with a viable rooftop and 365 MWp of roof capacity. 85% run a generator, and together they spend ₦93.2bn a year on energy.

Viable buildings

12,001

Usable roof area

1.62 km²

365 MWp roof capacity

Energy spend

₦93.2bn/yr

80 GWh/yr burned on generators

Median payback

2.9 yr

Median IRR 39% (cash saved)

The savings bracket for Lagos Island

Approach B

Cash saved

What these buildings stop paying — merit order, capped at current spend.

Current energy spend₦93.2bn/yr

Year-one cash saved₦85.2bn

Lifetime cash saved₦4.11tn

NPV₦584bn

Median IRR39%

Median payback2.9 yr

Unlocked energy24.3 GWh/yr

Approach A

Energy value (upper bracket)

What the energy is worth if full latent demand were met. Not cash saved.

Installed capacity204 MWp

Capex₦185bn

Year-one energy value₦84bn

Lifetime energy value₦3.74tn

NPV₦547bn

Median IRR47%

Median payback2.4 yr

Three ways to size Lagos Island's rooftops

Solar + battery. The default headline scenario, and the one the SEO fact base quotes. Prices the energy a full solar+storage system would deliver.

Baseline: mixed

Counterfactual: grid when available, generator otherwise, weighted by the NTL-derived grid availability. The realistic case, and what the headline numbers use. Always falls between grid and genset by construction.

Read with care: Sized to LATENT demand — the energy the building would use if it could. Against a cash baseline that only reflects today's spend this looks oversized; that is what sc3 exists to fix.

System size: 204 MWp
Capital cost: ₦185bn
Year 1 savings: ₦84bn/yr
NPV: ₦547bn
Median IRR: 47%
Median payback: 2.4 yr

The odds a rooftop in Lagos Island pays back quickly

Of the 12,001 buildings in Lagos Island with a modelled payback, 99.9% pay back inside five years and 69.9% inside three.

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How much of Lagos Island's demand actually gets met

Buildings in Lagos Island consume 251 GWh/yr but want 275 GWh/yr. The 9% they cannot buy is suppressed demand — load that appears the moment supply is reliable.

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Electricity billing bands in Lagos Island

Loading band economics…

How many rooftops in Lagos Island actually pay

Counted building by building on the cash-saved basis (merit-order sized, valued against what the building spends today), not read off an average. Shares are of the 12,001 buildings with a modelled result out of 12,001 in Lagos Island. 11,992 clear a positive NPV.

Payback

Under 3 years8,391 (70%)

Under 5 years11,983 (100%)

Under 7 years11,992 (100%)

Under 10 years11,996 (100%)

Return (IRR)

Above 10%11,995 (100%)

Above 15%11,992 (100%)

Above 20%11,985 (100%)

Above 25%11,967 (100%)

CO₂ avoided

139 kt/yr

Fuel avoided

25.4 million litres/yr

Energy unlocked

24.3 GWh/yr

Demand that is suppressed today

People served

54.8k

What hardware costs right now

Median advertised rates from our Nigerian market tracker — the same prices used to cost a system in Lagos Island.

Solar panels

₦250

₦/W

Inverters

₦127,419

₦/kVA

Batteries

₦177,500

₦/kWh

Full price tracker Size a home system Size a business system

Building mix in Lagos Island

Electricity billing band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
A	11,793	10,060	₦90.5bn	₦82.8bn	39%	2.9 yr
B	208	179	₦2.75bn	₦2.37bn	45%	2.4 yr

Load profile

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	4,602	3,706	₦14.4bn	₦12.6bn	39%	2.9 yr
Commercial General	3,839	3,398	₦54.5bn	₦50.5bn	39%	2.6 yr
Commercial Retail	1,771	1,627	₦4.5bn	₦4.47bn	39%	2.9 yr
Anchor	762	629	₦11.2bn	₦9.83bn	49%	2.1 yr
Worship	398	337	₦1.02bn	₦1.02bn	39%	2.9 yr
Mall Retail	253	231	₦2.18bn	₦2.09bn	39%	2.9 yr
Hospitality	215	184	₦4.2bn	₦3.55bn	45%	2.4 yr
Productive Use	62	45	₦229m	₦227m	39%	2.9 yr
Industrial	48	40	₦690m	₦676m	49%	2.1 yr
Automotive	33	28	₦124m	₦124m	35%	3.1 yr
Filling Station	18	14	₦129m	₦129m	39%	2.6 yr

Roof size band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
100 250m2	4,132	3,490	₦22.5bn	₦20.2bn	39%	2.6 yr
50 100m2	2,882	2,488	₦4.7bn	₦4.04bn	39%	2.9 yr
250 1000m2	1,738	1,468	₦41.9bn	₦39.7bn	45%	2.4 yr
Under 30m2	1,658	1,425	₦728m	₦650m	39%	2.9 yr
30 50m2	1,453	1,255	₦1.25bn	₦1.02bn	39%	2.9 yr
Over 1000m2	138	113	₦22.1bn	₦19.5bn	53%	2.1 yr

Settlement type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Urban Centre	11,216	9,590	₦78.3bn	₦72.2bn	39%	2.9 yr
Unclassified	785	649	₦14.9bn	₦13bn	39%	2.9 yr

Building type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential Informal	4,519	3,669	₦13.9bn	₦12.5bn	39%	2.9 yr
Kiosk Shop	1,465	1,318	₦979m	₦979m	39%	2.9 yr
Commercial Corridor	1,234	1,113	₦16.6bn	₦16.2bn	39%	2.6 yr
Commercial	906	783	₦12.6bn	₦12.1bn	39%	2.9 yr
Commercial	865	799	₦14.1bn	₦13.7bn	45%	2.4 yr
Commercial Retail	579	547	₦5.47bn	₦5.44bn	39%	2.9 yr
Institutional	349	297	₦5.44bn	₦5.21bn	35%	3.1 yr
Unknown	333	277	₦4.59bn	₦4.11bn	35%	3.1 yr
Educational Facility	230	189	₦1.42bn	₦1.42bn	51%	2.1 yr
School	229	188	₦824m	₦824m	49%	2.1 yr
Worship Center	171	145	₦306m	₦306m	39%	2.9 yr
Place Of Worship	160	133	₦230m	₦230m	39%	2.9 yr

Land use

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
(Unset)	11,309	9,565	₦87.8bn	₦79.9bn
Retail	610	598	₦4.8bn	₦4.75bn
Industrial	66	60	₦311m	₦309m
Commercial	16	16	₦265m	₦264m

Not published for this cube: Median IRR, Median payback.

Lead segment

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Standard	8,366	6,982	₦43.6bn	₦38bn	39%	2.9 yr
SME High	2,850	2,611	₦38bn	₦36.9bn	41%	2.6 yr
Enterprise	785	646	₦11.6bn	₦10.3bn	49%	2.1 yr

Demand tier

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
4.0	5,578	4,686	₦52.9bn	₦47.4bn
3.0	2,615	2,214	₦4.38bn	₦3.16bn
2.0	1,870	1,633	₦994m	₦936m
5.0	1,239	1,125	₦13.2bn	₦13bn
6.0	465	394	₦21.7bn	₦20.6bn
1.0	208	177	₦56.9m	₦49.8m
0.0	26	10	₦964k	₦964k