Oyo State

Rooftop solar in Irepo, Oyo: what the roofs are worth

Irepo has 36,663 buildings with a viable rooftop and 580 MWp of roof capacity. 29% run a generator, and together they spend ₦38bn a year on energy.

Viable buildings

36,663

Usable roof area

2.59 km²

580 MWp roof capacity

Energy spend

₦38bn/yr

34.9 GWh/yr burned on generators

Median payback

4.1 yr

Median IRR 27% (cash saved)

The savings bracket for Irepo

Approach B

Cash saved

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

Current energy spend₦38bn/yr

Year-one cash saved₦37.3bn

Lifetime cash saved₦1.96tn

NPV₦307bn

Median IRR27%

Median payback4.1 yr

Unlocked energy24.5 GWh/yr

Approach A

Energy value (upper bracket)

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

Installed capacity107 MWp

Capex₦103bn

Year-one energy value₦87.9bn

Lifetime energy value₦4.16tn

NPV₦698bn

Median IRR93%

Median payback1.1 yr

Three ways to size Irepo'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: 107 MWp
Capital cost: ₦103bn
Year 1 savings: ₦87.9bn/yr
NPV: ₦698bn
Median IRR: 93%
Median payback: 1.1 yr

The odds a rooftop in Irepo pays back quickly

Of the 36,201 buildings in Irepo with a modelled payback, 56.4% pay back inside five years and 30.6% inside three.

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How much of Irepo's demand actually gets met

Buildings in Irepo consume 58.4 GWh/yr but want 82.9 GWh/yr. The 30% they cannot buy is suppressed demand — load that appears the moment supply is reliable.

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Electricity billing bands in Irepo

Loading band economics…

How many rooftops in Irepo 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 36,201 buildings with a modelled result out of 36,663 in Irepo. 22,029 clear a positive NPV.

Payback

Under 3 years11,085 (31%)

Under 5 years20,407 (56%)

Under 7 years22,029 (61%)

Under 10 years23,022 (64%)

Return (IRR)

Above 10%22,788 (62%)

Above 15%22,029 (60%)

Above 20%20,959 (57%)

Above 25%19,413 (53%)

CO₂ avoided

65.8 kt/yr

Fuel avoided

19 million litres/yr

Energy unlocked

24.5 GWh/yr

Demand that is suppressed today

People served

156k

What hardware costs right now

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

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 Irepo

Electricity billing band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
D	18,548	6,958	₦25bn	₦24.4bn	29%	3.9 yr
E	18,115	3,667	₦13.1bn	₦12.9bn	5%	15.9 yr

Load profile

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	32,762	9,082	₦26.4bn	₦25.7bn	23%	4.6 yr
Commercial General	2,192	851	₦10.4bn	₦10.3bn	37%	2.9 yr
Commercial Retail	1,370	498	₦319m	₦319m	35%	3.1 yr
Anchor	179	138	₦873m	₦856m	63%	1.6 yr
Worship	83	30	₦23.2m	₦23.2m	33%	3.1 yr
Industrial	68	19	₦102m	₦101m	37%	2.9 yr
Filling Station	8	7	₦12.3m	₦12.2m	53%	1.9 yr
Hospitality	1	0	₦89.9k	₦89.9k	35%	3.1 yr

Roof size band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Under 30m2	16,509	2,053	₦423m	₦416m	5%	17.6 yr
100 250m2	9,372	4,635	₦19.8bn	₦19.3bn	37%	2.9 yr
50 100m2	4,496	1,663	₦1.95bn	₦1.91bn	27%	3.9 yr
30 50m2	3,818	949	₦407m	₦400m	21%	5.1 yr
250 1000m2	2,454	1,316	₦14.8bn	₦14.8bn	49%	2.1 yr
Over 1000m2	14	9	₦599m	₦599m	47%	1.9 yr

Settlement type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Unclassified	16,869	1,869	₦7.41bn	₦6.78bn	5%	17.1 yr
Urban Centre	16,764	7,475	₦26.3bn	₦26.2bn	35%	3.1 yr
Urban	2,026	1,262	₦4.31bn	₦4.27bn	67%	1.6 yr
Rural	1,004	19	₦49.9m	₦49.9m	7%	15.1 yr

Building type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Shed	15,876	1,533	₦227m	₦227m	5%	17.6 yr
Residential	7,140	4,125	₦22.9bn	₦22.3bn	67%	1.6 yr
Residential Small	5,654	2,608	₦2.58bn	₦2.53bn	27%	3.9 yr
Residential Formal	1,885	102	₦167m	₦165m	25%	4.1 yr
Residential Informal	1,692	682	₦464m	₦464m	27%	3.9 yr
Kiosk Shop	1,370	498	₦319m	₦319m	35%	3.1 yr
Commercial	1,078	527	₦7.18bn	₦7.16bn	37%	2.9 yr
Commercial Corridor	957	230	₦2.67bn	₦2.67bn	35%	3.1 yr
Apartment	360	25	₦43.8m	₦43.8m	27%	3.9 yr
Institutional	172	95	₦474m	₦474m	41%	2.6 yr
Duplex	121	6	₦11m	₦11m	27%	3.9 yr
Educational Facility	64	51	₦205m	₦205m	79%	1.4 yr

Land use

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
(Unset)	36,663	10,625	₦38bn	₦37.3bn

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	34,373	9,704	₦27.2bn	₦26.5bn	25%	4.4 yr
SME High	2,043	764	₦9.87bn	₦9.84bn	37%	2.9 yr
Enterprise	247	157	₦974m	₦957m	53%	2.1 yr

Demand tier

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
0.0	15,878	1,509	₦216m	₦216m
3.0	10,193	5,923	₦23.8bn	₦23.7bn
4.0	3,999	860	₦3.16bn	₦2.65bn
2.0	3,731	1,442	₦1.06bn	₦1.04bn
5.0	1,352	537	₦4.71bn	₦4.71bn
1.0	1,143	180	₦101m	₦100m
6.0	367	174	₦4.96bn	₦4.94bn