An energetic and exergetic analysis of a 20 MW photovoltaic grid-connected plant installed harsh climate was presented. It found that the annual energy produced was 35892.2 MWh, close to the expected theoretical value. The performance ratio and energy efficiency are 71.71% and 10.82%, respectively. The exergy efficiency and thermal exergy were 4.96% and 5.32 MW, respectively. The increase in thermal exergy loss has the highest effect on the decrease in exergy efficiency values. Similarly, solar radiation is the most influential environmental parameter on thermal exergy loss, with a determination coefficient of 80%.This study conducts a performance analysis of a 20 MW grid-connected PV plant in desert climatic conditions. Energetic and exergetic analyses of the PV plant have been performed. The annual average energy efficiency of subsystems 1 and 2 and the PV plant are 10.95%, 10.69% and 10.82%, respectively. The annual monthly average exergy efficiency and thermal exergy were 4.96% and 5.32 MW, respectively. The decrease in exergy efficiency values was matched by an increase in the values of thermal exergy loss, solar radiation, wind speed, and ambient temperature, where the thermal exergy loss has the highest effect. Similarly, solar radiation is the most influential environmental parameter on thermal exergy loss, with a determination coefficient of 80%.