Adamawa State

Rooftop solar in Gombi, Adamawa: what the roofs are worth

Gombi has 123,301 buildings with a viable rooftop and 791 MWp of roof capacity. 5% run a generator, and together they spend ₦8.01bn a year on energy.

Viable buildings

123,301

Usable roof area

3.59 km²

791 MWp roof capacity

Energy spend

₦8.01bn/yr

6.02 GWh/yr burned on generators

Median payback

13.4 yr

Median IRR 9% (cash saved)

The savings bracket for Gombi

Approach B

Cash saved

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

Current energy spend₦8.01bn/yr

Year-one cash saved₦7.95bn

Lifetime cash saved₦449bn

NPV₦63.4bn

Median IRR9%

Median payback13.4 yr

Unlocked energy11 GWh/yr

Approach A

Energy value (upper bracket)

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

Installed capacity64.6 MWp

Capex₦70.1bn

Year-one energy value₦73bn

Lifetime energy value₦3.45tn

NPV₦595bn

Median IRR101%

Median payback1.1 yr

Three ways to size Gombi'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: 64.6 MWp
Capital cost: ₦70.1bn
Year 1 savings: ₦73bn/yr
NPV: ₦595bn
Median IRR: 101%
Median payback: 1.1 yr

The odds a rooftop in Gombi pays back quickly

Of the 119,309 buildings in Gombi with a modelled payback, 24.9% pay back inside five years and 5.8% inside three.

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How much of Gombi's demand actually gets met

Buildings in Gombi consume 17.4 GWh/yr but want 28.4 GWh/yr. The 39% they cannot buy is suppressed demand — load that appears the moment supply is reliable.

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Electricity billing bands in Gombi

Loading band economics…

How many rooftops in Gombi 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 119,309 buildings with a modelled result out of 123,301 in Gombi. 43,717 clear a positive NPV.

Payback

Under 3 years6,934 (6%)

Under 5 years29,654 (25%)

Under 7 years43,892 (37%)

Under 10 years57,162 (48%)

Return (IRR)

Above 10%53,498 (43%)

Above 15%43,717 (35%)

Above 20%32,878 (27%)

Above 25%25,194 (20%)

CO₂ avoided

17.3 kt/yr

Fuel avoided

3.23 million litres/yr

Energy unlocked

11 GWh/yr

Demand that is suppressed today

People served

291k

What hardware costs right now

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

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 Gombi

Electricity billing band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
D	38,989	1,465	₦2.14bn	₦2.14bn	5%	15.9 yr
E	29,038	845	₦1.24bn	₦1.19bn	7%	15.9 yr
B	28,292	2,201	₦2.61bn	₦2.61bn	17%	6.1 yr
C	26,982	2,029	₦2.01bn	₦2.01bn	15%	6.9 yr

Load profile

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	121,311	5,083	₦5.68bn	₦5.62bn	9%	13.4 yr
Commercial Retail	735	497	₦127m	₦127m	49%	2.1 yr
Commercial General	658	444	₦1.19bn	₦1.19bn	49%	2.1 yr
Anchor	412	335	₦940m	₦940m	69%	1.4 yr
Worship	170	166	₦59.2m	₦59.2m	61%	1.6 yr
Industrial	14	14	₦12.6m	₦12.6m	71%	1.4 yr
Hospitality	1	1	₦723k	₦723k	61%	1.6 yr

Roof size band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Under 30m2	67,896	2,462	₦351m	₦351m	5%	17.1 yr
30 50m2	26,001	1,165	₦527m	₦526m	11%	9.1 yr
50 100m2	21,784	1,509	₦1.54bn	₦1.54bn	27%	4.1 yr
100 250m2	6,741	1,102	₦2.7bn	₦2.65bn	31%	3.6 yr
250 1000m2	852	292	₦2.34bn	₦2.34bn	31%	3.4 yr
Over 1000m2	27	10	₦545m	₦545m	31%	3.4 yr

Settlement type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Urban Centre	37,500	2,446	₦2.82bn	₦2.82bn	17%	6.1 yr
Unclassified	35,154	1,096	₦1.88bn	₦1.88bn	5%	17.4 yr
Urban	18,763	938	₦1.4bn	₦1.35bn	9%	13.4 yr
Rural	18,172	1,096	₦969m	₦969m	7%	14.9 yr
Dense Urban	13,712	964	₦943m	₦940m	15%	6.9 yr

Building type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Shed	69,721	2,413	₦340m	₦340m	5%	16.4 yr
Residential Small	23,043	1,789	₦1.71bn	₦1.71bn	29%	3.9 yr
Residential Formal	13,978	0	₦58.3m	₦58.3m	9%	8.6 yr
Residential	9,859	881	₦3.53bn	₦3.47bn	19%	5.1 yr
Residential Informal	4,699	0	₦42.6m	₦42.6m	11%	7.6 yr
Kiosk Shop	735	497	₦127m	₦127m	49%	2.1 yr
Institutional	291	248	₦784m	₦784m	57%	1.9 yr
Commercial	282	127	₦635m	₦635m	39%	2.9 yr
Educational Facility	164	145	₦156m	₦156m	81%	1.4 yr
School	120	101	₦92.6m	₦92.6m	79%	1.4 yr
Commercial Corridor	110	110	₦290m	₦290m	51%	2.1 yr
Healthcare Facility	64	46	₦160m	₦160m	51%	2.1 yr

Land use

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
(Unset)	123,293	6,540	₦8.01bn	₦7.95bn
Farmyard	8	0	₦211k	₦211k

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	122,483	5,954	₦6.13bn	₦6.07bn	9%	13.4 yr
Enterprise	426	349	₦953m	₦953m	71%	1.4 yr
SME High	392	237	₦926m	₦926m	49%	2.1 yr

Demand tier

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
0.0	69,744	2,434	₦341m	₦341m
2.0	17,001	1,416	₦1.69bn	₦1.64bn
3.0	14,817	1,646	₦4.3bn	₦4.3bn
4.0	13,022	286	₦385m	₦385m
1.0	8,406	593	₦443m	₦443m
5.0	278	150	₦545m	₦545m
6.0	33	15	₦304m	₦304m