Strings and inverter

Choose the panel, the inverter and the site's minimum temperature — the calculator shows the allowed number of panels per string and checks your choice.

Panel modelInverterMin. temperature, °C

Panels per stringfrom 5 to 8

Panel Voc in frost60.2 V

Panel Vmp in heat35.8 V

Input MPPT150–425 V

Input maximum voltage500 V

Your string, panels

Open in the designer

How it is calculated

Open-circuit voltage rises in frost. Per HD 60364-7-712 (Annex B): U_oc max = U_oc·(1 + α·(T_min − 25)/100), T_min being the site's absolute minimum air temperature and α the panel coefficient; with T_min or α unknown — 1.2·U_oc. A string must stay below the input's maximum voltage; the operating voltage with hot cells must stay within the MPPT window; the winter upper MPPT limit and the input current are checked too.

The calculation is preliminary. A qualified engineer must check it before installation. Codes: DBN V.1.2-2:2006 (Ukraine) and the Eurocode; for other countries — snow and wind values from the national annex, entered by hand.

Ground frame designer

Design the ground frame for your solar plant

The calculator’s values go to the designer: then the frame, the DBN checks and the estimate.

Design the frame All calculators