Nasarawa State

Rooftop solar in Keana, Nasarawa: what the roofs are worth

Keana has 36,000 buildings with a viable rooftop and 259 MWp of roof capacity. 6% run a generator, and together they spend ₦6.38bn a year on energy.

Viable buildings

36,000

Usable roof area

1.17 km²

259 MWp roof capacity

Energy spend

₦6.38bn/yr

5.47 GWh/yr burned on generators

Median payback

16.9 yr

Median IRR 5% (cash saved)

The savings bracket for Keana

Approach B

Cash saved

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

Current energy spend₦6.38bn/yr

Year-one cash saved₦6.35bn

Lifetime cash saved₦345bn

NPV₦50.7bn

Median IRR5%

Median payback16.9 yr

Unlocked energy6.64 GWh/yr

Approach A

Energy value (upper bracket)

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

Installed capacity41.2 MWp

Capex₦42bn

Year-one energy value₦38.3bn

Lifetime energy value₦1.8tn

NPV₦306bn

Median IRR89%

Median payback1.1 yr

Three ways to size Keana'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: 41.2 MWp
Capital cost: ₦42bn
Year 1 savings: ₦38.3bn/yr
NPV: ₦306bn
Median IRR: 89%
Median payback: 1.1 yr

The odds a rooftop in Keana pays back quickly

Of the 34,525 buildings in Keana with a modelled payback, 25.3% pay back inside five years and 6.1% inside three.

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How much of Keana's demand actually gets met

Buildings in Keana consume 11.9 GWh/yr but want 18.5 GWh/yr. The 36% they cannot buy is suppressed demand — load that appears the moment supply is reliable.

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Electricity billing bands in Keana

Loading band economics…

How many rooftops in Keana 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 34,525 buildings with a modelled result out of 36,000 in Keana. 10,568 clear a positive NPV.

Payback

Under 3 years2,099 (6%)

Under 5 years8,749 (25%)

Under 7 years10,567 (31%)

Under 10 years12,125 (35%)

Return (IRR)

Above 10%11,796 (33%)

Above 15%10,568 (29%)

Above 20%9,236 (26%)

Above 25%7,662 (21%)

CO₂ avoided

12.5 kt/yr

Fuel avoided

2.89 million litres/yr

Energy unlocked

6.64 GWh/yr

Demand that is suppressed today

People served

134k

What hardware costs right now

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

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 Keana

Electricity billing band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
E	21,703	815	₦2.22bn	₦2.22bn	5%	17.4 yr
D	10,654	575	₦2.46bn	₦2.43bn	5%	17.6 yr
C	3,643	764	₦1.7bn	₦1.7bn	21%	5.1 yr

Load profile

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	33,721	1,505	₦4.3bn	₦4.3bn	5%	17.1 yr
Commercial General	1,057	270	₦771m	₦771m	35%	3.1 yr
Commercial Retail	976	242	₦41.2m	₦41.2m	33%	3.4 yr
Anchor	168	105	₦1.23bn	₦1.2bn	51%	2.1 yr
Worship	62	24	₦19.7m	₦19.7m	33%	3.1 yr
Industrial	16	8	₦10.9m	₦10.9m	37%	1.6 yr

Roof size band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Under 30m2	23,489	618	₦106m	₦105m	3%	18.9 yr
50 100m2	4,691	372	₦496m	₦496m	27%	4.1 yr
30 50m2	4,418	259	₦109m	₦108m	9%	13.6 yr
100 250m2	2,758	640	₦2.08bn	₦2.08bn	27%	3.9 yr
250 1000m2	612	247	₦2.34bn	₦2.34bn	29%	3.9 yr
Over 1000m2	32	18	₦1.25bn	₦1.22bn	53%	1.9 yr

Settlement type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Unclassified	19,747	371	₦1.51bn	₦1.51bn	3%	18.4 yr
Rural	8,597	420	₦997m	₦997m	5%	16.1 yr
Urban	5,533	637	₦1.97bn	₦1.97bn	19%	5.4 yr
Dense Urban	2,103	726	₦1.9bn	₦1.87bn	27%	4.1 yr
(Unset)	20	0	₦1.9m	₦1.9m	27%	3.9 yr

Building type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Shed	23,381	409	₦80.7m	₦80.7m	3%	18.6 yr
Residential Small	5,845	307	₦548m	₦545m	25%	4.4 yr
Residential	2,295	430	₦3.46bn	₦3.46bn	27%	3.9 yr
Residential Formal	1,259	0	₦20.1m	₦20.1m	11%	8.6 yr
Kiosk Shop	976	242	₦41.2m	₦41.2m	33%	3.4 yr
Residential Informal	939	359	₦196m	₦196m	27%	3.9 yr
Commercial	481	187	₦437m	₦437m	35%	3.1 yr
Commercial Corridor	287	30	₦155m	₦155m	35%	3.1 yr
Market	186	1	₦5.8m	₦5.8m	27%	4.1 yr
Institutional	115	66	₦609m	₦609m	43%	2.4 yr
Educational Facility	62	42	₦175m	₦175m	71%	1.4 yr
School	35	26	₦38.8m	₦38.8m	69%	1.6 yr

Land use

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
(Unset)	36,000	2,154	₦6.38bn	₦6.35bn

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	35,060	1,831	₦4.55bn	₦4.55bn	5%	16.9 yr
SME High	768	217	₦592m	₦592m	35%	3.1 yr
Enterprise	172	106	₦1.23bn	₦1.21bn	49%	2.1 yr

Demand tier

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
0.0	23,399	419	₦81.3m	₦81.3m
2.0	4,469	541	₦722m	₦722m
1.0	4,004	438	₦258m	₦258m
3.0	2,535	691	₦4.81bn	₦4.78bn
4.0	1,275	64	₦362m	₦362m
5.0	299	1	₦120m	₦120m
6.0	19	0	₦25.8m	₦25.8m