<p>This research addresses the energy crisis and the need for alternative energy sources, particularly low-quality heat. This research aims to improve system performance in the solar field using zeotropic mixed organic (ZMO) working fluids. The Organic Rankine Cycle (ORC) is a regenerative cycle powered by solar collectors and four ZMO fluids. An RSM optimization approach is used to optimize the combination of ZMO fluids with a varying mass fraction (m/f)s, expander inlet temperature (EIT), and internal heat exchanger (IHE) in the solar-powered ORC. The four m/f of five ZMOs are tested in a temperature range of 250C-1000C. The impact of input properties with intake expander temperature on temperature glides, electrical power produced (EPD), and thermal efficiency of the ORC is examined. Experiments using the L₂₇ orthogonal array of RSM and ANOVA were performed to investigate the impact of input characteristics and interactions. The study found that butane/pentane ZMO fluid with IHE and greater EIT are more important characteristics for enhancing EPD and TE with TGs at increasing mass percentages. RSM and Desirability analysis are used to determine the best circumstances for reducing TGs while increasing EPD and TE. The best input attributes were employed in the confirmation test, and the estimated values of the output attributes and the experimental findings agreed quite well. </p>