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    Oyo State

    Rooftop solar in Itesiwaju, Oyo: what the roofs are worth

    Itesiwaju has 48,269 buildings with a viable rooftop and 488k kWp of roof capacity. 96% run a generator, and together they spend ₦36.2bn a year on energy.

    Viable buildings

    48,269

    Usable roof area

    2.19m m²

    488k kWp roof capacity

    Energy spend

    ₦36.2bn/yr

    31.2m kWh/yr burned on generators

    Median payback

    2.1 yr

    Median IRR 49% (cash saved)

    The savings bracket for Itesiwaju

    Approach B

    Cash saved

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

    Current energy spend₦36.2bn/yr
    Year-one cash saved₦35.6bn
    Lifetime cash saved₦1.51tn
    NPV₦244bn
    Median IRR49%
    Median payback2.1 yr
    Unlocked energy29.7m kWh/yr
    Approach A

    Energy value (upper bracket)

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

    Installed capacity144k kWp
    Capex₦140bn
    Year-one energy value₦142bn
    Lifetime energy value₦6.58tn
    NPV₦1.14tn
    Median IRR115%
    Median payback0.9 yr

    Three ways to size Itesiwaju'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
    144k kWp
    Capital cost
    ₦140bn
    Year 1 savings
    ₦142bn/yr
    NPV
    ₦1.14tn
    Median IRR
    115%
    Median payback
    0.9 yr

    How many rooftops in Itesiwaju 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. 48,269 of 48,269 clear a positive NPV.

    Payback

    Under 3 years36,957 (77%)
    Under 5 years46,056 (95%)
    Under 7 years48,269 (100%)
    Under 10 years48,269 (100%)

    Return (IRR)

    Above 10%48,269 (100%)
    Above 15%48,269 (100%)
    Above 20%46,120 (96%)
    Above 25%45,935 (95%)
    CO₂ avoided

    66.5m kg/yr

    Fuel avoided

    20.8m L/yr

    Energy unlocked

    29.7m kWh/yr

    Demand that is suppressed today

    People served

    269k

    What hardware costs right now

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

    Solar panels

    250

    ₦/W

    Inverters

    127,419

    ₦/kVA

    Batteries

    177,500

    ₦/kWh

    Building mix in Itesiwaju

    Load profile

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    Residential47,21845,127₦34.1bn₦33.6bn49%2.1 yr
    Commercial General314299₦523m₦523m41%2.6 yr
    Anchor234227₦1.12bn₦1.09bn59%1.9 yr
    Industrial199193₦184m₦183m47%2.4 yr
    Worship122119₦138m₦138m51%2.1 yr
    Hospitality5454₦24.2m₦24.2m55%1.9 yr
    Commercial Retail5252₦5.9m₦5.9m55%1.9 yr
    Productive Use5151₦5.2m₦5.2m43%2.6 yr
    Filling Station2423₦47.7m₦47.2m49%2.1 yr
    Automotive11₦7.49m₦7.49m49%2.1 yr

    Roof size band

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    Under 30m227,75927,167₦669m₦666m47%2.4 yr
    30 50m27,3767,111₦987m₦985m49%2.1 yr
    100 250m26,2665,552₦17.4bn₦17.1bn57%1.9 yr
    50 100m25,1804,882₦3.05bn₦3.05bn51%2.1 yr
    250 1000m21,6661,415₦13.8bn₦13.6bn57%1.9 yr
    Over 1000m22219₦215m₦215m69%1.6 yr

    Settlement type

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    Unclassified30,66530,538₦9.69bn₦9.22bn47%2.4 yr
    Dense Urban7,9136,041₦12bn₦11.9bn49%2.1 yr
    Rural7,4897,489₦7.88bn₦7.85bn55%1.9 yr
    Urban2,2022,078₦6.64bn₦6.63bn55%1.9 yr

    Lead segment

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    Standard47,76745,660₦34.8bn₦34.3bn49%2.1 yr
    Enterprise407394₦1.3bn₦1.27bn53%2.1 yr
    SME High9592₦112m₦112m43%2.6 yr

    Demand tier

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    0.027,53727,325₦454m₦454m
    3.08,3347,833₦29.7bn₦29.4bn
    2.05,7075,455₦3.42bn₦3.19bn
    1.03,6983,670₦1.16bn₦1.16bn
    4.02,9921,863₦1.46bn₦1.46bn
    5.010₦583k₦583k

    Nearby LGAs in Oyo

    How these numbers are produced

    Approach A — energy value (upper bracket)

    Sizes the system to the building's full latent demand and values that energy at the mixed grid/generator tariff. It answers what the energy is worth — not what anyone currently pays.

    Approach B — cash saved (lower bracket)

    Sizes the system to demand that is actually served today, values it by merit order (solar displaces generator kWh first) and caps it at current spend. It answers what a building stops paying.

    Cohort: Viable rooftops (≥0.6 kWp potential).

    • Demand is modelled latent demand, not metered consumption.
    • Fuel is priced at ₦1,800/litre (operator-set). NBS reported ₦3,277/litre for May 2026 — on that basis every naira figure here is roughly 1.8× understated.
    • Generator ownership is a model output, not a survey result: it follows from the grid-availability scale and the 25% demand-suppression assumption.
    • Approach A prices energy nobody currently buys. Its savings must never be read as cash saved.
    • Demand is MODELLED LATENT demand, not metered consumption.
    • Generator ownership is model output, not survey.
    • Medians do not combine across groups — re-derive from the histograms.
    • Per-building files are float32 with 4 significant figures; cast to float64 before summing, because polars keeps Float32 sums in Float32.
    • Null scenario fields mean the roof cannot host 0.6 kWp, not zero savings.
    • `genset` was previously named `diesel` and now uses the segment's real fuel.
    • Ordering holds by construction: grid savings < mixed < genset.