Imo State

Rooftop solar in Njaba, Imo: what the roofs are worth

Njaba has 35,672 buildings with a viable rooftop and 836 MWp of roof capacity. 48% run a generator, and together they spend ₦15.1bn a year on energy.

Viable buildings

35,672

Usable roof area

3.72 km²

836 MWp roof capacity

Energy spend

₦15.1bn/yr

13.6 GWh/yr burned on generators

Median payback

4.4 yr

Median IRR 25% (cash saved)

The savings bracket for Njaba

Approach B

Cash saved

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

Current energy spend₦15.1bn/yr

Year-one cash saved₦15bn

Lifetime cash saved₦775bn

NPV₦120bn

Median IRR25%

Median payback4.4 yr

Unlocked energy12.4 GWh/yr

Approach A

Energy value (upper bracket)

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

Installed capacity54.3 MWp

Capex₦56.6bn

Year-one energy value₦47.6bn

Lifetime energy value₦2.27tn

NPV₦378bn

Median IRR97%

Median payback1.1 yr

Three ways to size Njaba'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: 54.3 MWp
Capital cost: ₦56.6bn
Year 1 savings: ₦47.6bn/yr
NPV: ₦378bn
Median IRR: 97%
Median payback: 1.1 yr

The odds a rooftop in Njaba pays back quickly

Of the 35,394 buildings in Njaba with a modelled payback, 69.0% pay back inside five years and 45.9% inside three.

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How much of Njaba's demand actually gets met

Buildings in Njaba consume 21 GWh/yr but want 33.4 GWh/yr. The 37% they cannot buy is suppressed demand — load that appears the moment supply is reliable.

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Electricity billing bands in Njaba

Loading band economics…

How many rooftops in Njaba 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 35,394 buildings with a modelled result out of 35,672 in Njaba. 28,529 clear a positive NPV.

Payback

Under 3 years16,252 (46%)

Under 5 years24,412 (69%)

Under 7 years28,479 (80%)

Under 10 years31,709 (90%)

Return (IRR)

Above 10%31,009 (87%)

Above 15%28,529 (80%)

Above 20%25,573 (72%)

Above 25%17,830 (50%)

CO₂ avoided

27.6 kt/yr

Fuel avoided

8.11 million litres/yr

Energy unlocked

12.4 GWh/yr

Demand that is suppressed today

People served

108k

What hardware costs right now

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

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 Njaba

Electricity billing band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
E	11,196	4,728	₦3.69bn	₦3.66bn	25%	4.4 yr
D	10,937	4,392	₦2.91bn	₦2.91bn	25%	4.4 yr
C	8,851	4,887	₦5.37bn	₦5.31bn	45%	2.4 yr
B	4,688	3,151	₦3.1bn	₦3.08bn	41%	2.6 yr

Load profile

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	35,195	16,752	₦12.2bn	₦12.2bn	25%	4.4 yr
Anchor	200	173	₦1.5bn	₦1.42bn	71%	1.4 yr
Commercial General	199	173	₦1.24bn	₦1.21bn	59%	1.9 yr
Commercial Retail	50	36	₦9.57m	₦9.57m	63%	1.6 yr
Worship	16	13	₦37.8m	₦37.8m	61%	1.6 yr
Industrial	11	10	₦54.3m	₦54.3m	71%	1.4 yr
Filling Station	1	1	₦775k	₦775k	65%	1.6 yr

Roof size band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
100 250m2	12,958	6,110	₦5.9bn	₦5.9bn	25%	4.4 yr
50 100m2	7,667	3,736	₦919m	₦919m	25%	4.4 yr
Under 30m2	6,305	3,001	₦244m	₦244m	19%	5.4 yr
30 50m2	4,570	2,192	₦270m	₦270m	21%	4.9 yr
250 1000m2	4,119	2,083	₦6.5bn	₦6.44bn	29%	3.6 yr
Over 1000m2	53	36	₦1.23bn	₦1.18bn	59%	1.9 yr

Settlement type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Urban Centre	34,353	16,653	₦14.8bn	₦14.7bn	25%	4.4 yr
Unclassified	1,319	505	₦278m	₦278m	23%	4.6 yr

Building type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	11,826	5,787	₦9.77bn	₦9.77bn	25%	4.4 yr
Residential Small	11,410	5,585	₦1.42bn	₦1.42bn	25%	3.6 yr
Shed	7,418	3,500	₦313m	₦313m	19%	5.6 yr
Residential Formal	2,195	1,371	₦495m	₦495m	31%	3.6 yr
Residential Informal	1,944	292	₦146m	₦146m	25%	4.4 yr
Apartment	324	152	₦59.2m	₦59.2m	25%	4.4 yr
Institutional	119	103	₦935m	₦912m	57%	1.9 yr
Duplex	75	63	₦23.3m	₦23.3m	45%	2.4 yr
Commercial	72	64	₦683m	₦653m	65%	1.6 yr
Educational Facility	67	57	₦313m	₦313m	81%	1.4 yr
School	64	55	₦145m	₦145m	79%	1.4 yr
Kiosk Shop	50	36	₦9.57m	₦9.57m	63%	1.6 yr

Land use

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
(Unset)	35,672	17,158	₦15.1bn	₦15bn

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	35,388	16,910	₦12.8bn	₦12.8bn	25%	4.4 yr
Enterprise	211	183	₦1.56bn	₦1.48bn	71%	1.4 yr
SME High	73	65	₦684m	₦654m	65%	1.6 yr

Demand tier

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
3.0	20,741	10,255	₦12.9bn	₦12.8bn
0.0	7,421	3,502	₦314m	₦314m
4.0	3,991	1,747	₦1.11bn	₦1.11bn
2.0	3,304	1,556	₦391m	₦391m
1.0	207	92	₦14.5m	₦14.5m
5.0	8	6	₦362m	₦332m