Solar glossary
Capex (capital cost): what it means and why it matters
The upfront cost of installing the system: panels, inverter, battery, mounting and labour.
Why it matters in Nigeria
Divided by system size it gives ₦/kWp, the single fastest way to sanity-check a quote against the local market.
How PureWatts measures it
Total Capex (Solar + battery)
sum_sc2_capex_ngn
Sum over the buildings in the group. Total install cost: PV + inverter + battery.
Solar + battery: PV sized to cover FULL demand including round-trip losses: kwp = min(demand x (daylight + (1-daylight)/0.90) x 1.10 / net_yield, pv_max_kwp); battery = night demand / (0.80 DoD x sqrt(0.90)), capped at 2.0x PV kWp
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.
Sum over the buildings in the group.
Total Capex (Merit-order sized)
sum_sc3_capex_ngn
Sum over the buildings in the group. Total install cost: PV + inverter + battery.
Solar + battery, merit-order sized: Same engine as sc2, but the target is what the building CONSUMES today x 1.5 (MO_SIZING_UPLIFT) rather than full latent demand.
In Osun, sizing sc2 to latent demand while crediting it only with displacing current spend produced a 6x-oversized system and a negative IRR that said nothing about solar. sc3 is the fix, not an alternative opinion.
Sum over the buildings in the group.
See these numbers for your area
Every state and local government area page reports capex (capital cost) for its own rooftops. Browse the Nigeria rooftop solar data.