The output voltage is approximately 45. 8 volts under standard test conditions. Voc (open-circuit voltage) is the highest — typically 38–55 V for residential panels — and is what the inverter sees when no current is flowing. Why this Calculator is. three phase solar system from 5kw-300kw For the products, Each set solar power system has power on&off test 100 times per hour. Our products are qualified with CE, ROHS, ISO, SGS certification For our project case: Our products have been sold. Enter the values of total number of cells, C and voltage per cells, V pc (V) to determine the value of solar panel voltage, V sp (V). Solar Panel Voltage is a key factor in the design and functionality of solar energy systems. Losses come from inverter efficiency, wiring, temperature, and dirt. Increasing panel count or choosing higher wattage.