Solar Panel Volts
The voltage of a solar panel is based on the number of solar cells in a panel.Each different solar technology has a characteristic voltage per cell based on the physical properties of the materials that the cell is composed of.
There are two voltages that are important for a solar module:
The open circuit voltage (Voc) is the maximum voltage that the cell will produce and it occurs when there is no current supplied by the module.
The power point voltage (Vpp) is the voltage at which the maximum power is available from the cell.
Solar panels always produce DC current and can be used directly with a system that works on DC. But the biggest challenge is that the wattage, voltage and current from a panel vary. It varies with the environmental temperature and also with the amount of light it gets.
In fact higher temperature decreases the power output. A colder day and a good sunlight will result in better output from a solar panel.