Quick Answer: A 100-watt solar panel typically produces 17-22 volts under standard test conditions, with most panels outputting around 18-20 volts. The exact voltage depends on the panel technology, temperature, and lighting conditions. Understanding solar panel voltage output is crucial for system. Discover the expected voltage output of a 100-watt solar panel, including nominal, open-circuit, and maximum power point voltages, to optimize your solar system. This range is primarily due to the type of solar cells used and the design of the panel. Here's a breakdown: 12 Volts: Many 100 watt solar panels are designed to operate at 12 volts, making them ideal for small off-grid systems. A 100W solar panel typically generates a voltage output in the range of 12 to 36 volts, depending on its design and configuration.