PureWatts AI

    Solar energy assistant

    📍 Home

    Hi there! 👋

    I'm your PureWatts AI assistant. Ask me anything about solar energy, system sizing, or how to use the platform.

    Skip to content

    Nasarawa State

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

    Lafia has 251,249 buildings with a viable rooftop and 3.81m kWp of roof capacity. 61% run a generator, and together they spend ₦78.6bn a year on energy.

    Viable buildings

    251,249

    Usable roof area

    17m m²

    3.81m kWp roof capacity

    Energy spend

    ₦78.6bn/yr

    67.7m kWh/yr burned on generators

    Median payback

    2.9 yr

    Median IRR 37% (cash saved)

    The savings bracket for Lafia

    Approach B

    Cash saved

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

    Current energy spend₦78.6bn/yr
    Year-one cash saved₦77.5bn
    Lifetime cash saved₦3.28tn
    NPV₦495bn
    Median IRR37%
    Median payback2.9 yr
    Unlocked energy93.3m kWh/yr
    Approach A

    Energy value (upper bracket)

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

    Installed capacity502k kWp
    Capex₦465bn
    Year-one energy value₦412bn
    Lifetime energy value₦19.2tn
    NPV₦3.24tn
    Median IRR105%
    Median payback1.1 yr

    Three ways to size Lafia'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
    502k kWp
    Capital cost
    ₦465bn
    Year 1 savings
    ₦412bn/yr
    NPV
    ₦3.24tn
    Median IRR
    105%
    Median payback
    1.1 yr

    How many rooftops in Lafia 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. 251,249 of 251,249 clear a positive NPV.

    Payback

    Under 3 years127,994 (51%)
    Under 5 years156,157 (62%)
    Under 7 years251,249 (100%)
    Under 10 years251,249 (100%)

    Return (IRR)

    Above 10%251,249 (100%)
    Above 15%251,249 (100%)
    Above 20%158,831 (63%)
    Above 25%147,029 (59%)
    CO₂ avoided

    158m kg/yr

    Fuel avoided

    36.5m L/yr

    Energy unlocked

    93.3m kWh/yr

    Demand that is suppressed today

    People served

    451k

    What hardware costs right now

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

    Solar panels

    250

    ₦/W

    Inverters

    127,419

    ₦/kVA

    Batteries

    177,500

    ₦/kWh

    Building mix in Lafia

    Load profile

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    Residential238,718147,625₦52.1bn₦51.7bn39%2.9 yr
    Commercial General5,6251,975₦11.7bn₦11.6bn25%4.4 yr
    Commercial Retail3,4981,068₦354m₦354m25%4.4 yr
    Worship1,7711,449₦1.3bn₦1.3bn55%1.9 yr
    Anchor1,218843₦12.3bn₦11.8bn47%2.1 yr
    Productive Use188181₦152m₦152m63%1.6 yr
    Hospitality12078₦329m₦326m57%1.9 yr
    Industrial6642₦243m₦242m35%2.9 yr
    Filling Station3633₦35.3m₦35.3m61%1.6 yr
    Mall Retail80₦1.46m₦1.46m25%4.4 yr
    Automotive11₦225k₦225k53%2.1 yr

    Roof size band

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    50 100m269,62742,143₦12.5bn₦12.4bn39%2.6 yr
    Under 30m268,37744,832₦1.76bn₦1.76bn41%2.6 yr
    100 250m258,22031,601₦27.8bn₦27.5bn27%4.1 yr
    30 50m243,83428,859₦3.07bn₦3.07bn53%2.1 yr
    250 1000m210,7035,541₦20.1bn₦20.1bn25%4.4 yr
    Over 1000m2488319₦13.3bn₦12.7bn37%2.9 yr

    Settlement type

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    Urban Centre98,53927,778₦21.1bn₦20.7bn19%5.9 yr
    Unclassified51,42147,309₦20.2bn₦19.8bn63%1.6 yr
    Urban43,60034,081₦19.1bn₦18.8bn55%1.9 yr
    Rural32,56332,095₦13.2bn₦13.2bn75%1.4 yr
    Dense Urban25,12512,032₦4.98bn₦4.96bn25%4.4 yr
    (Unset)10₦19.3k₦19.3k19%6.1 yr

    Lead segment

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    Standard245,195150,923₦56.5bn₦56.1bn39%2.9 yr
    SME High4,8221,529₦9.83bn₦9.66bn25%4.4 yr
    Enterprise1,232843₦12.3bn₦11.8bn47%2.4 yr

    Demand tier

    SegmentBuildings With generator Spend ₦/yr Cash saved yr 1 (B) Median IRR Median payback
    2.081,75846,856₦18.8bn₦18.5bn
    0.064,78655,254₦2.32bn₦2.32bn
    3.043,58923,053₦37.1bn₦36.5bn
    1.029,72621,901₦5.79bn₦5.78bn
    4.028,1955,789₦9.61bn₦9.54bn
    5.02,829364₦3.39bn₦3.24bn
    6.036678₦1.65bn₦1.65bn

    Nearby LGAs in Nasarawa

    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.