Each PV cell produces anywhere between 0.5V and 0.6V, according to Wikipedia; this is known as Open-Circuit Voltage or V OC for short. To be more accurate, a typical open circuit voltage of a solar cell is 0.58 volts (at 77°F or 25°C). All the PV cells in all solar panels have the same 0.58V voltage.
[pdf] A solar panel rated at 120 watts typically operates at a voltage range between 17 to 22 volts, depending on its specific design and construction. This voltage range is primarily influenced by the materials used in the panel’s photovoltaic cells and the overall configuration of the panel system.
[pdf] Typically, a high-voltage solar panel operates above 48 volts, commonly used in utility-scale and large commercial solar installations. These panels are designed for systems where long-distance transmission is required, minimizing energy loss over distances.
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