The rapid increase in computing power has facilitated the use of computational fluid dynamics (CFD) as an attractive tool for simulating solar systems. As a result, researchers have conducted numerous experimental and numerical studies on solar technologies, with an increasing emphasis on the utilization of CFD for simulation purposes. Hence, this article is intended to be the first of a two-part assessment of recent improvements in the use of ANSYS-Fluent CFD simulation in solar systems. In this part, the article aims to provide a comprehensive overview of CFD simulations, using ANSYS-Fluent, for different solar systems without concentrators, including solar thermal systems, hybrid photovoltaic/thermal (PV/T) systems, and photovoltaic/phase change material (PV/PCM) systems, while the concentrating solar systems are covered in the second part. Further, this review study includes informative data about the simulations, including the considered assumptions, models, and solution methods that were used with different cooling fluids, PCM materials, absorber designs, and innovative system designs. The present assessment also highlights the results and some remarks that show different important additional information such as the applied radiation and melting/solidification models. Besides, validation techniques and errors between the experimental work and simulations are introduced. In general, the ANSYS-Fluent CFD results were validated and it was possible to optimize many design parameters with minimal effort and expense. Recent research indicated that nanofluids could be a better alternative to conventional fluids to improve the thermal functionality of flat plate and hybrid PV/T systems. Effective cooling mechanisms could reduce PV panel temperature by 15–20%. Besides, integrating PCM with PV systems could enhance efficiency by 33–46% on summer days. Incorporating different nanomaterials and using fined PV/PCM configurations, the PV/PCM system demonstrated improved cost-effectiveness, while a foam layer outside the PCM could extend PV thermal management time by 55%. Many other conclusions about the commonly used physical models, solution methods, and assumptions dealing with different systems are highlighted inside. The article also identifies additional research proposals and challenges that must be addressed to advance the study of this topic.