Solar Panel & Inverter Sizing Calculator (kWp, Roof Area & Annual kWh)

Calculate how many solar panels you need, array peak power in kWp, inverter size and roof area from your monthly electricity bill in kWh.

Monthly Consumption en Factura (kWh/mes)

Radiación Zona (Horas Solares Pico HSP)

Potencia de cada Panel Solar (Wp)

Porcentaje de Cobertura Solar Deseado

Número de Paneles 6 Boards

Potencia Campo Solar 3.00 kWp

Inversor Recomendado 3.0 kW

Superficie de Tejado 13 m²

Photovoltaic Sizing Formula by Peak Sun Hours (PSH)

Photovoltaic Standard (IEC 61724): Calculation accounts for a real-world system Performance Ratio (PR = 0.80) covering thermal, wiring and inverter losses.

Potencia Pico Necesaria (kWp) = Daily Consumption Objetivo (kWh/día) / (HSP × PR_0.80)

Average Annual Solar Production by Installed kWp

Potencia Campo (kWp)	Nº Paneles (500 Wp)	Inversor Nominal	Producción Anual Media	Superficie Mínima
2,0 kWp	4 paneles	2,0 kW	3.000 - 3.400 kWh/año	9 m²
3,0 kWp	6 paneles	3,0 kW	4.500 - 5.100 kWh/año	13 m²
5,0 kWp	10 paneles	5,0 kW	7.500 - 8.500 kWh/año	22 m²
8,0 kWp	16 paneles	8,0 kW	12.000 - 13.600 kWh/año	35 m²

Frequently Asked Technical Questions (FAQ)

How do you calculate wire size for voltage drop?

For DC and single-phase AC circuits, cross-sectional area S (mm²) = (2 × Length × Current × ρ) / Voltage Drop (V). Always verify that conductor ampacity meets NFPA 70 (NEC Table 310.16) or IEC 60364.

What is the maximum allowable voltage drop?

Under NEC and IEC standards, the recommended maximum voltage drop is 3% for branch circuits and 5% total for combined feeder and branch circuits.