This study marks the pioneering utilization of thermal efficiency involving non-Newtonian Carreau nanofluids within parabolic trough solar collectors (PTSCs). The research delves into nanofluids encompassing copper-engine oil, copper (II) oxide-engine oil, and iron (II, III) oxide-engine oil Carreau nanofluids within PTSCs. Evaluation of PTSC’s heat efficiency encompasses a spectrum of physical phenomena, including porous medium effects, slanted magnetic fields, non-uniform heat sources/sinks, thermal radiation, viscous dissipation, and thermophoresis. Additionally, the study investigates the influence of several parameters governing nanofluid flow on velocity, temperature, entropy generation, skin friction coefficient, and local Nusselt number of the Carreau nanofluids within PTSC setups. The research adopts a theoretical model that represents the flow and thermal dynamics of PTSCs integrated into a solar-powered aircraft, highlighting the pivotal role of nanoparticle thermal conductivity. Numerical results reveal substantial enhancements in heat efficiency within engine-oil Carreau nanofluids, encompassing copper, copper (II) oxide, and iron (II, III) oxide. These enhancements translate to relative increments of 68.490%, 50.292%, and 42.013% in maximum heat performance, underscoring the potential of Carreau nanofluids to elevate PTSC efficiency, suggesting a theoretical model for their potential application in solar-powered aircraft. Overall, this study holds promise for cleaner and more sustainable energy applications in the realms of solar energy and solar-powered aircraft. The execution of intricate engineering simulations falls beyond the scope of our current study. © Akadémiai Kiadó, Budapest, Hungary 2024.