In solar panels, it's generated when sunlight excites electrons in the photovoltaic (PV) cells. The optimal operating voltage under load. The system. If you're planning an installation with 19 photovoltaic panels, understanding their combined voltage is critical for selecting compatible inverters, batteries, and safety components. Each solar panel has three key voltage ratings printed on its label: The maximum voltage. Solar panel output voltage typically ranges from 5-40 volts for individual panels, with system voltages reaching up to 1500V for large-scale installations. What is Solar Panel Output Voltage? Solar panel. Here's what you need to know about voltage for solar panels: Open Circuit Voltage (Voc): This is the maximum voltage your panel can produce, usually measured on a bright, cold morning.