Free online tool

Solar PV String Sizing Calculator

Check solar module strings against inverter voltage and current limits

Solar module

Array and inverter

Cold string Voc
—
Hot string Vmp
—
Array Imp
—
Array power
—
Recommended series-module range from these limits
Use the lowest expected cell temperature for cold Voc and the highest expected cell temperature for hot Vmp. Cell temperature can differ substantially from ambient air temperature.

Solar string voltage and current check

This calculator applies module voltage temperature coefficients to test a proposed series string at cold and hot conditions. It checks cold open-circuit voltage, the operating MPPT window, maximum-power current and short-circuit current against the inverter limits entered above.

Always confirm the exact module datasheet, inverter manual, local electrical code, conductor limits, required safety factors and manufacturer design rules. This screening calculator does not replace a design reviewed by a qualified solar professional.