Solar calculators
Four calculators, each built on the formulas printed on the topic pages and on Global Solar Atlas yield data per city. Inputs stay in your browser; nothing is sent anywhere. Every result shows its assumptions and lets you change them.
Calculators
Solar system sizing
Appliance list or daily kWh, peak load, backup hours and city → PV kWp, panel count, inverter kVA, battery kWh, sized on the worst month.
Panel count and roof area
Target kWp and panel wattage → number of panels, nominal array size, roof area with spacing, expected daily and annual output for your city.
Battery runtime
Battery Ah and volts (or kWh), chemistry and load → hours of backup after depth of discharge and inverter efficiency.
Generator vs solar
Generator size, hours and fuel price vs a solar system cost → naira per kWh, annual cost and simple payback, with September 2026 defaults you can override.
How the calculators work
Each tool is a few hundred lines of plain JavaScript that runs in your browser. The formulas are the ones on the panel, battery, inverter and economics pages, and are repeated under each result. Solar yield per city is the Global Solar Atlas PVOUT layer documented on the resource page. Defaults for fuel and tariff are the dated inputs on the Nigeria hub.
An estimate from stated formulas and typical values, for planning and for checking quotations. It is not an engineering design, does not replace a load audit and site survey by a qualified installer, and does not account for shading, roof orientation, cable losses or local standards. ZEUS is not an engineering firm.