The electrical characteristics of a photovoltaic array are summarised in the relationship between the output current and voltage. The amount and intensity of solar insolation (solar irradiance) controls the amount of output current ( ), and the operating temperature of the solar cells affects the output voltage ( ) of the PV array.
The open-circuit voltage, V OC, is the maximum voltage available from a solar cell, and this occurs at zero current. The open-circuit voltage corresponds to the amount of forward bias on the solar cell due to the bias of the solar cell junction with the light-generated current. The open-circuit voltage is shown on the IV curve below.
Open Circuit Voltage: The voltage across the solar cell’s terminals when there is no load connected, typically around 0.5 to 0.6 volts. Efficiency: The efficiency of a solar cell is the ratio of its maximum electrical power output to the input solar radiation power, indicating how well it converts light to electricity.
The output power of the PV cell is voltage times current, so there is no output power for a short-circuit condition because of VOUT or for an open-circuit condition because of IOUT = 0. Above the short-circuit point, the PV cell operates with a resistive load.
It depends on manufacturing techniques and temperature, but not significantly on light intensity or exposed surface area. The open circuit voltage of a solar cell is typically around 0.5 to 0.6 volts, denoted as V oc. The maximum electrical power one solar cell can deliver at its standard test condition.
Other important characteristics include how the current varies as a function of the output voltage and as a function of light intensity or irradiance. The current-voltage (I-V) curve for a PV cell shows that the current is essentially constant over a range of output voltages for a specified amount of incident light energy.
OverviewEquivalent circuit of a solar cellWorking explanationPhotogeneration of charge carriersThe p–n junctionCharge carrier separationConnection to an external loadSee also
An equivalent circuit model of an ideal solar cell''s p–n junction uses an ideal current source (whose photogenerated current increases with light intensity) in parallel with a diode (whose current represents recombination losses). To account for resistive losses, a shunt resistance and a series resistance are added as lumped elements. The resulting output current equals the photogenerated curr…