Energy needs of the world can be achieved by considering photovoltaic (PV) energy as a large-scale source that has been proved by recent growth in production of PV modules and decrement in their prices. Deserts are in demand for the purpose of energy generation through PV, began utilized by countries too. This article scrutinizes the issue of offbeat energy generation by contrasting the two 100 MW PV power plants analogous in location, environment and installed equipment. Irregularity of performance is conducted and assessed by plane of array (POA), annual deterioration rate, inter row spacing, PV cleaning frequency, equipment losses, temperature and other factors. Actual monthly generation differences of a year are examined considering deterioration rate and vice versa for the two in sight. Inter row spacing and POA are emphasized with sun path plots and eclipse diagrams for maximizing the energy yield. Any discrepancy of these parameters during design stage prompted with pecuniary loss that ramified over the life cycle of the project. While a meliorated design impacted a USD 0.85 million financial saving with supplement of energy output.