Oyo State

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

Iseyin has 96,265 buildings with a viable rooftop and 1.92 GWp of roof capacity. 30% run a generator, and together they spend ₦62.1bn a year on energy.

Viable buildings

96,265

Usable roof area

8.55 km²

1.92 GWp roof capacity

Energy spend

₦62.1bn/yr

49.1 GWh/yr burned on generators

Median payback

4.4 yr

Median IRR 25% (cash saved)

The savings bracket for Iseyin

Approach B

Cash saved

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

Current energy spend₦62.1bn/yr

Year-one cash saved₦58.5bn

Lifetime cash saved₦3.12tn

NPV₦457bn

Median IRR25%

Median payback4.4 yr

Unlocked energy47.8 GWh/yr

Approach A

Energy value (upper bracket)

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

Installed capacity216 MWp

Capex₦221bn

Year-one energy value₦171bn

Lifetime energy value₦8.07tn

NPV₦1.33tn

Median IRR81%

Median payback1.4 yr

Three ways to size Iseyin'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: 216 MWp
Capital cost: ₦221bn
Year 1 savings: ₦171bn/yr
NPV: ₦1.33tn
Median IRR: 81%
Median payback: 1.4 yr

The odds a rooftop in Iseyin pays back quickly

Of the 95,092 buildings in Iseyin with a modelled payback, 65.0% pay back inside five years and 26.8% inside three.

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How much of Iseyin's demand actually gets met

Buildings in Iseyin consume 105 GWh/yr but want 153 GWh/yr. The 31% they cannot buy is suppressed demand — load that appears the moment supply is reliable.

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Electricity billing bands in Iseyin

Loading band economics…

How many rooftops in Iseyin 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 95,092 buildings with a modelled result out of 96,265 in Iseyin. 70,367 clear a positive NPV.

Payback

Under 3 years25,473 (27%)

Under 5 years61,793 (65%)

Under 7 years70,307 (74%)

Under 10 years74,804 (79%)

Return (IRR)

Above 10%74,081 (77%)

Above 15%70,367 (73%)

Above 20%64,240 (67%)

Above 25%56,591 (59%)

CO₂ avoided

112 kt/yr

Fuel avoided

28.7 million litres/yr

Energy unlocked

47.8 GWh/yr

Demand that is suppressed today

People served

506k

What hardware costs right now

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

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 Iseyin

Electricity billing band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
C	39,460	13,450	₦24.8bn	₦24.7bn	25%	4.4 yr
E	24,595	1,741	₦15.1bn	₦11.8bn	7%	15.4 yr
B	22,766	11,958	₦13.7bn	₦13.7bn	33%	3.4 yr
D	9,444	2,136	₦8.45bn	₦8.26bn	21%	4.9 yr

Load profile

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	93,049	27,275	₦52.3bn	₦48.8bn	25%	4.4 yr
Commercial General	1,464	939	₦6.35bn	₦6.34bn	37%	2.9 yr
Commercial Retail	629	417	₦141m	₦141m	35%	3.1 yr
Anchor	517	315	₦2.65bn	₦2.63bn	43%	2.4 yr
Industrial	444	239	₦473m	₦469m	47%	2.4 yr
Worship	106	68	₦53.3m	₦53.3m	41%	2.4 yr
Filling Station	33	17	₦17.9m	₦17.9m	35%	3.1 yr
Hospitality	14	10	₦65.5m	₦65.5m	39%	2.1 yr
Mall Retail	5	1	₦3.69m	₦3.56m	35%	3.1 yr
Productive Use	3	3	₦1.17m	₦1.17m	59%	1.9 yr
Automotive	1	1	₦409k	₦409k	41%	2.6 yr

Roof size band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Under 30m2	30,436	5,619	₦600m	₦591m	7%	14.9 yr
100 250m2	26,383	10,409	₦24.7bn	₦22.6bn	25%	4.1 yr
50 100m2	15,477	4,519	₦2.89bn	₦2.83bn	25%	4.4 yr
30 50m2	12,732	3,071	₦693m	₦691m	21%	5.1 yr
250 1000m2	11,180	5,638	₦29.6bn	₦28.3bn	35%	3.1 yr
Over 1000m2	57	29	₦3.58bn	₦3.45bn	39%	2.6 yr

Settlement type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Urban Centre	52,150	20,880	₦27.9bn	₦27.9bn	25%	4.1 yr
Unclassified	33,041	3,113	₦17.5bn	₦15.9bn	7%	14.6 yr
Urban	7,148	3,531	₦9.9bn	₦9.87bn	27%	4.1 yr
Dense Urban	2,497	1,060	₦1.74bn	₦1.74bn	25%	4.1 yr
Rural	1,429	701	₦5.01bn	₦3.05bn	27%	4.1 yr

Building type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential Formal	26,245	11,629	₦8.44bn	₦8.43bn	25%	4.1 yr
Shed	25,319	2,724	₦367m	₦367m	5%	16.6 yr
Residential	14,645	6,873	₦38.7bn	₦35.2bn	27%	4.1 yr
Residential Small	13,978	4,046	₦3.21bn	₦3.15bn	25%	4.4 yr
Residential Informal	8,756	104	₦340m	₦340m	23%	4.6 yr
Apartment	2,803	1,282	₦929m	₦917m	25%	4.1 yr
Duplex	1,148	612	₦355m	₦355m	35%	3.1 yr
Kiosk Shop	628	417	₦141m	₦141m	35%	3.1 yr
Institutional	608	344	₦2.21bn	₦2.21bn	37%	2.9 yr
Commercial Corridor	521	330	₦1.91bn	₦1.91bn	35%	3.1 yr
Commercial	344	291	₦3.27bn	₦3.26bn	49%	2.1 yr
Industrial Site	308	153	₦290m	₦290m	37%	2.9 yr

Land use

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
(Unset)	95,793	29,156	₦61bn	₦57.4bn
Farmland	309	38	₦59.5m	₦59.5m
Industrial	109	90	₦807m	₦807m
Farmyard	54	1	₦183m	₦182m

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	94,404	28,097	₦53.7bn	₦50.2bn	25%	4.4 yr
Enterprise	953	549	₦3.11bn	₦3.08bn	43%	2.4 yr
SME High	908	639	₦5.21bn	₦5.2bn	39%	2.9 yr

Demand tier

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
4.0	34,386	13,466	₦14.7bn	₦14.6bn
0.0	24,710	2,702	₦363m	₦363m
3.0	23,350	10,125	₦41.3bn	₦38.1bn
2.0	9,536	2,188	₦2.58bn	₦2.33bn
1.0	3,813	505	₦376m	₦372m
5.0	369	228	₦1.62bn	₦1.62bn
6.0	101	71	₦1.06bn	₦1.05bn