MODULE PERFORMANCE

• Total electrical energy output P(watt) of a PV module =  input voltage(V)  X operating current (I)

 

Module I-V curve (12V DC nominal)

 

• A current-voltage (I-V) curve shows the possible combinations of current and voltage output of a PV device.

• This maximum current is known as the short-circuit current, I_sc.

• At the I_sc point, the power output is zero since the voltage is zero.

• Conversely, the maximum voltage occurs when there is a break in the circuit.

• At the open-circuit voltage, V_oc, the power output is also zero, because the current is zero.

• There is a point on the knee of the curve where the maximum power output is located—the maximum power point (I_mp & V_mp). 

• The I-V curve of a PV device is based on the device being under standard conditions of sunlight (1000 W/m²) or one-sun (peak sun) and  temperature (25^oC). It assumes there is no shading on the device.
  
  Effect of insolation on module performance
  
  
• Temperature condition is assumed to be 25^oC.  Temperatures higher than this value will decrease the module output.
  
  
  
  Effect of temperature on module performance