Photovoltaic/thermal systems are one of the most efficient types of solar collectors because they absorb solar radiation and generate electricity and heat simultaneously. For the first time, this paper presents an investigation into the impact of red wine-rGO/H₂O nanofluid and paraffin wax on the thermohydraulic properties of a photovoltaic/thermal system. The study focuses on three innovative nonlinear arrangements of the serpentine tubes. The effects of these materials and configurations are analyzed through numerical simulations. To improve the performance, environmentally friendly materials, including red wine-rGO/H₂O nanofluid and paraffin wax, have been used. Various performative parameters such as electrical and thermal efficiency of the photovoltaic/thermal system, exergy, and nanofluid concentration were investigated. The results demonstrated a significant enhancement in the system’s performance when using innovative serpentine tubes instead of simple tubes for the fluid flow path. The use of paraffin C18 increases electrical efficiency, while the use of paraffin C22 improves thermal efficiency. Moreover, the incorporation of phase change materials along with the utilization of innovative geometries in the serpentine tube led to a notable improvement in the outlet temperature of the fluid, increasing it by 2.43 K. Simultaneously, it substantially reduced the temperature of the photovoltaic cells, lowering it by 21.55 K. In addition, the new model demonstrated significant improvements in both thermal and electrical efficiency compared to the simple model. Specifically, the maximum thermal efficiency improvement reached 69.2%, while the maximum electrical efficiency improvement reached 11.7%.

In this paper, we analyzed vertical bio convection in nanofluids containing microorganisms. The novelty of this article is the numerical and analytical investigation of magnetic flow, radiation heat transfer, and viscous dissipation on bio convective fluid flow using the Five-order Runge-Kutta technique. Utilizing similitude parameters, determined ODE (ordinary differential equation) equations from partial differential equations for continuity, momentum, energy, and nanofluid concentration. Five-order Runge-Kutta was then used to solve the equations. The results show that it has a more significant influence on and then and. In addition, it exerts a force on neighboring particles, which causes them to shift from a hot zone to a great region. The density of microorganisms inside a part rises as it grows; when Le rises and Ha remains the same, x(ξ) falls, and When Ha rises, and Le remains the same, x(ξ) fall.