Nasarawa State

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

Karu has 377,110 buildings with a viable rooftop and 5.99 GWp of roof capacity. 11% run a generator, and together they spend ₦46.7bn a year on energy.

Viable buildings

377,110

Usable roof area

26.8 km²

5.99 GWp roof capacity

Energy spend

₦46.7bn/yr

43 GWh/yr burned on generators

Median payback

6.4 yr

Median IRR 15% (cash saved)

The savings bracket for Karu

Approach B

Cash saved

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

Current energy spend₦46.7bn/yr

Year-one cash saved₦45.7bn

Lifetime cash saved₦2.49tn

NPV₦359bn

Median IRR15%

Median payback6.4 yr

Unlocked energy47.7 GWh/yr

Approach A

Energy value (upper bracket)

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

Installed capacity212 MWp

Capex₦217bn

Year-one energy value₦159bn

Lifetime energy value₦7.52tn

NPV₦1.23tn

Median IRR73%

Median payback1.4 yr

Three ways to size Karu'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: 212 MWp
Capital cost: ₦217bn
Year 1 savings: ₦159bn/yr
NPV: ₦1.23tn
Median IRR: 73%
Median payback: 1.4 yr

The odds a rooftop in Karu pays back quickly

Of the 346,980 buildings in Karu with a modelled payback, 34.3% pay back inside five years and 10.3% inside three.

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How much of Karu's demand actually gets met

Buildings in Karu consume 96.4 GWh/yr but want 144 GWh/yr. The 33% they cannot buy is suppressed demand — load that appears the moment supply is reliable.

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Electricity billing bands in Karu

Loading band economics…

How many rooftops in Karu 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 346,980 buildings with a modelled result out of 377,110 in Karu. 188,198 clear a positive NPV.

Payback

Under 3 years35,854 (10%)

Under 5 years118,853 (34%)

Under 7 years188,324 (54%)

Under 10 years245,904 (71%)

Return (IRR)

Above 10%236,012 (63%)

Above 15%188,198 (50%)

Above 20%135,574 (36%)

Above 25%94,554 (25%)

CO₂ avoided

88.6 kt/yr

Fuel avoided

18.4 million litres/yr

Energy unlocked

47.7 GWh/yr

Demand that is suppressed today

People served

354k

What hardware costs right now

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

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 Karu

Electricity billing band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
B	148,810	13,865	₦9.08bn	₦9.07bn	17%	5.6 yr
A	69,432	3,786	₦3.19bn	₦3.19bn	17%	6.1 yr
E	65,670	5,728	₦13.1bn	₦12.7bn	7%	13.9 yr
C	52,449	11,510	₦11.9bn	₦11.8bn	19%	5.4 yr
D	40,749	5,512	₦9.42bn	₦8.84bn	9%	9.9 yr

Load profile

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Residential	370,927	38,978	₦21.8bn	₦21.6bn	15%	6.6 yr
Commercial General	2,842	428	₦4.22bn	₦4.21bn	35%	3.1 yr
Commercial Retail	1,688	100	₦80.9m	₦80.9m	35%	3.1 yr
Anchor	900	424	₦20bn	₦19.2bn	45%	2.4 yr
Worship	499	323	₦274m	₦274m	59%	1.9 yr
Industrial	86	44	₦154m	₦152m	39%	2.6 yr
Hospitality	79	37	₦125m	₦125m	37%	2.9 yr
Productive Use	65	61	₦19.3m	₦19.3m	65%	1.6 yr
Mall Retail	13	4	₦24.9m	₦24.9m	37%	2.9 yr
Filling Station	10	2	₦3.11m	₦3.11m	35%	3.1 yr
Automotive	1	0	₦119k	₦119k	31%	3.4 yr

Roof size band

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Under 30m2	115,424	9,290	₦1.06bn	₦1.05bn	5%	15.4 yr
100 250m2	99,714	12,515	₦9.32bn	₦9.15bn	25%	4.6 yr
50 100m2	88,609	8,914	₦2.52bn	₦2.5bn	15%	6.9 yr
30 50m2	54,077	5,386	₦941m	₦941m	11%	8.9 yr
250 1000m2	18,640	3,982	₦11.5bn	₦11.5bn	29%	3.9 yr
Over 1000m2	646	314	₦21.3bn	₦20.6bn	33%	3.1 yr

Settlement type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Urban Centre	221,159	19,324	₦13.2bn	₦13.2bn	17%	5.6 yr
Unclassified	63,174	5,244	₦12.4bn	₦11.4bn	7%	15.1 yr
Urban	43,284	10,291	₦12.6bn	₦12.6bn	17%	5.9 yr
Rural	28,661	3,535	₦6.1bn	₦6.07bn	11%	8.9 yr
Dense Urban	20,832	2,007	₦2.39bn	₦2.37bn	13%	6.9 yr

Building type

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)	Median IRR	Median payback
Shed	99,133	10,580	₦1.36bn	₦1.36bn	9%	13.4 yr
Residential Informal	91,796	2,274	₦1.29bn	₦1.29bn	13%	6.6 yr
Residential Formal	87,942	3,672	₦1.32bn	₦1.32bn	15%	6.1 yr
Residential Small	57,890	11,663	₦2.81bn	₦2.79bn	17%	6.1 yr
Residential	33,209	10,719	₦15bn	₦14.8bn	27%	3.9 yr
Kiosk Shop	1,741	157	₦93.3m	₦93.3m	35%	3.1 yr
Commercial Corridor	955	39	₦785m	₦785m	35%	3.1 yr
Commercial	900	143	₦1.97bn	₦1.96bn	35%	3.1 yr
Institutional	652	372	₦19.1bn	₦18.3bn	47%	2.1 yr
Unknown	561	65	₦793m	₦791m	31%	3.4 yr
Apartment	534	50	₦11.8m	₦11.8m	25%	4.4 yr
Duplex	404	17	₦7.06m	₦7.06m	23%	4.6 yr

Land use

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
(Unset)	376,345	40,167	₦46.6bn	₦45.6bn
Commercial	757	234	₦42m	₦42m
Farmland	5	0	₦15.4k	₦15.4k
Industrial	3	0	₦18.4k	₦18.4k

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	374,262	39,762	₦23.7bn	₦23.5bn	15%	6.6 yr
SME High	1,923	205	₦2.86bn	₦2.85bn	35%	3.1 yr
Enterprise	925	434	₦20.1bn	₦19.3bn	45%	2.4 yr

Demand tier

Segment	Buildings	With generator	Spend ₦/yr	Cash saved yr 1 (B)
2.0	93,655	11,237	₦4.09bn	₦3.92bn
0.0	93,178	10,606	₦1.32bn	₦1.32bn
3.0	80,604	13,143	₦33.8bn	₦33bn
4.0	78,693	3,118	₦4.96bn	₦4.95bn
1.0	29,887	2,270	₦676m	₦653m
5.0	948	18	₦1.19bn	₦1.18bn
6.0	145	9	₦618m	₦618m