Exergy Efficiency and Enviroeconomic Analysis of Solar Photovoltaic Power in Nepal

As Nepal has been combating the energy crisis for decades, renewable energy will be crucial for its sustainable solution. This study aims to explore exergetic efficiency and environmental cost of solar photovoltaic (PV) technology in different cities of Nepal. The solar exergy efficiency of 12 cities of Nepal is evaluated herein with various parameters. It is observed that the city of Janakpur carries the highest amount of solar PV exergy efficiency of 25.77% and 36.27%, considering solar cell efficiency of 12% and 22.5%, respectively. Similarly, Bharatpur has the lowest solar PV exergy efficiency of 23.96% and 34.46%, with solar cell efficiency of 12% and 22.5%, respectively. In addition, average thermal exergy efficiency of solar PV varies between 7.69% and 17.70%, whereas total exergy efficiency varies between 19.71–29.58% and 30.19–40.2%. It is also found that the months of March and April carry the maximum average solar exergy efficiency, whereas July and August bring the least. In addition, an enviroeconomic study on various cities demonstrates that the cities of Mahendranagar and Dhangadhi produce solar power with higher environmental cost. Finally, the study encourages relevant policymakers to develop robust renewable energy policies that enhance the solar energy share in Nepalese energy dynamics.