Effect of solar irradiation

Effect of solar irradiation:- 

The output power of the PV module strongly depends upon the solar irradiation falling on it. The power output of a module increases linearly with the increase in the incident solar radiation. With the increase in the incident solar radiation more number of photons will be available to move the electrons from balance band to conduction band resulting into production of more current. The effect of solar irradiance on the I–V curve of the PV module is shown in Fig

the effect of irradiance and outdoor exposure on the performance of nine different types of PV technology modules from different manufacturers. After the exposure to outdoor conditions, the CIS and amorphous silicon modules showed strong degradation of the maximum power at STC, whereas mono-crystalline modules did not show any degradation. Finally, it is concluded that thin film PV modules perform better under low irradiance conditions. Yoo observed that the output power of PV modules increases with increase in irradiation level. The simulation results also showed good agreement with the experimental result. However, continuous solar exposure for long term also results in the degradation, affecting the performance of PV modules.