This paper provides a detailed analysis of the performance and economics of a 50 MW grid-connected solar power plant in Vietnam over a 4.5-year operational period from January 2020 to June 2024. The study systematically collected and analyzed key solar performance metrics

including the correlation between solar irradiance and temperature

as well as the relationship between irradiance and the plant’s performance ratio (PR). The findings indicate that PR ranged from 0.61% to 0.84%

with solar irradiance varying between 128 and 192 kWh/m2/month. The capacity utilization factor ranged from 12.82% to 19.47%

and the average final yield varied between 3.24 and 4.23 h/d

consistent with other studies. Power losses ranged from 50 to 130 MWh/month

totaling 5978.2 MWh over the period. The cumulative electricity generation reached 383 768 MWh. The economic analysis revealed a simple payback period of 7 years with a levelized cost of electricity of 0.05 USD/kWh. The study highlights the importance of implementing effective maintenance strategies to minimize the gap between theoretical and actual performance

thereby ensuring long-term economic viability

particularly in the context of high interest rates in developing countries.