Anambra State

Rooftop solar in Onitsha South, Anambra: what the roofs are worth

Onitsha South has 14,539 buildings with a viable rooftop and 516 MWp of roof capacity. 39% run a generator, and together they spend ₦19.6bn a year on energy.

Viable buildings

14,539

Usable roof area

2.29 km²

516 MWp roof capacity

Energy spend

₦19.6bn/yr

15.2 GWh/yr burned on generators

Median payback

3.9 yr

Median IRR 29% (cash saved)

The savings bracket for Onitsha South

Approach B

Cash saved

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

Current energy spend₦19.6bn/yr

Year-one cash saved₦19.1bn

Lifetime cash saved₦1.05tn

NPV₦150bn

Median IRR29%

Median payback3.9 yr

Unlocked energy23 GWh/yr

Approach A

Energy value (upper bracket)

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

Installed capacity78 MWp

Capex₦72.1bn

Year-one energy value₦43.4bn

Lifetime energy value₦2.01tn

NPV₦317bn

Median IRR69%

Median payback1.6 yr

Three ways to size Onitsha South'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: 78 MWp
Capital cost: ₦72.1bn
Year 1 savings: ₦43.4bn/yr
NPV: ₦317bn
Median IRR: 69%
Median payback: 1.6 yr

The odds a rooftop in Onitsha South pays back quickly

Of the 14,514 buildings in Onitsha South with a modelled payback, 78.4% pay back inside five years and 30.6% inside three.

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How much of Onitsha South's demand actually gets met

Buildings in Onitsha South consume 52.9 GWh/yr but want 75.9 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 Onitsha South

Loading band economics…

How many rooftops in Onitsha South 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 14,514 buildings with a modelled result out of 14,539 in Onitsha South. 12,936 clear a positive NPV.

Payback

Under 3 years4,447 (31%)

Under 5 years11,382 (78%)

Under 7 years12,939 (89%)

Under 10 years13,856 (95%)

Return (IRR)

Above 10%13,727 (94%)

Above 15%12,936 (89%)

Above 20%11,838 (81%)

Above 25%10,501 (72%)

CO₂ avoided

40.1 kt/yr

Fuel avoided

5.76 million litres/yr

Energy unlocked

23 GWh/yr

Demand that is suppressed today

People served

32.4k

What hardware costs right now

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

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 Onitsha South

Electricity billing band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
A	12,983	4,985	₦15.9bn	₦15.5bn	29%	3.9 yr
B	1,513	633	₦3.69bn	₦3.64bn	29%	3.9 yr
C	43	1	₦2.25m	₦2.25m	7%	14.1 yr

Load profile

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	12,714	4,570	₦5.19bn	₦5.14bn	29%	3.9 yr
Commercial General	844	511	₦6.45bn	₦6.4bn	39%	2.6 yr
Anchor	409	164	₦6.24bn	₦5.89bn	45%	2.4 yr
Commercial Retail	290	242	₦188m	₦188m	49%	2.1 yr
Worship	156	79	₦216m	₦216m	37%	2.9 yr
Industrial	47	21	₦1.12bn	₦1.1bn	41%	2.6 yr
Mall Retail	28	11	₦82.1m	₦82.1m	37%	2.9 yr
Hospitality	26	15	₦74.2m	₦74.2m	37%	2.6 yr
Filling Station	13	3	₦10.2m	₦10.2m	37%	2.9 yr
Productive Use	10	1	₦15m	₦15m	37%	2.9 yr
Automotive	2	2	₦3.11m	₦3.11m	39%	2.6 yr

Roof size band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
250 1000m2	4,049	1,429	₦7.83bn	₦7.81bn	29%	3.9 yr
100 250m2	3,557	1,436	₦3.13bn	₦3.08bn	29%	3.9 yr
50 100m2	2,531	974	₦457m	₦457m	25%	4.1 yr
Under 30m2	2,527	1,032	₦146m	₦144m	15%	6.9 yr
30 50m2	1,755	685	₦164m	₦164m	23%	4.9 yr
Over 1000m2	120	63	₦7.87bn	₦7.46bn	37%	2.9 yr

Settlement type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Urban Centre	14,173	5,468	₦18.3bn	₦17.8bn	29%	3.9 yr
Unclassified	366	151	₦1.29bn	₦1.29bn	29%	3.6 yr

Building type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential Informal	11,729	3,731	₦1.63bn	₦1.63bn	29%	3.9 yr
Residential	407	378	₦3.31bn	₦3.27bn	59%	1.9 yr
Residential Small	334	317	₦214m	₦209m	67%	1.6 yr
Kiosk Shop	275	234	₦143m	₦143m	49%	2.1 yr
Institutional	247	108	₦5.78bn	₦5.49bn	33%	3.4 yr
Shed	244	144	₦26.9m	₦26.9m	41%	2.6 yr
Commercial Corridor	219	193	₦1.47bn	₦1.46bn	49%	2.1 yr
Commercial	177	147	₦2.4bn	₦2.37bn	51%	2.1 yr
Unknown	134	47	₦634m	₦633m	33%	3.4 yr
Educational Facility	111	48	₦336m	₦336m	47%	2.1 yr
School	104	37	₦175m	₦175m	47%	2.4 yr
Commercial	93	30	₦776m	₦776m	37%	2.9 yr

Land use

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
(Unset)	14,394	5,474	₦17.4bn	₦17bn
Industrial	144	144	₦2.19bn	₦2.13bn
Farmyard	1	1	₦43k	₦43k

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	13,603	5,061	₦8.11bn	₦8.06bn	29%	3.9 yr
SME High	487	373	₦4.13bn	₦4.09bn	49%	2.1 yr
Enterprise	449	185	₦7.34bn	₦6.97bn	45%	2.4 yr

Demand tier

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
4.0	8,168	2,806	₦11.7bn	₦11.4bn
3.0	3,280	1,322	₦3.67bn	₦3.6bn
2.0	2,259	984	₦192m	₦190m
1.0	359	150	₦25.1m	₦25.1m
5.0	258	211	₦1.48bn	₦1.48bn
6.0	112	89	₦2.49bn	₦2.44bn
0.0	103	57	₦9.67m	₦9.67m