The following research paper deals with natural convection fluid flow & heat of transportation in a rectotrapezoidal enclosure (RTE) impregnated through the presence of non-Newtonian sodium alginate (SA) nanofluid in the presence of copper (Cu) nanoparticles as they relate to thermal insulation and solar collector systems. We harness the mathematical model based on a power-law representation model that is not Newtonian. To analyse these features, we use different power law indices (0.6 ≤ n ≤ 1.4) and Rayleigh numbers (103 ≤ Ra ≤ 106). The mathematical classical FEM application is harnessed in mathematically defining and, solving the governing equations under differential heating boundary conditions(BCs), where the vertical right domain wall is maintained at a lower temperature while the left-vertical domain wall is heated. Results indicate that pseudoplastic fluid flow behavior (n = 0.6) improves the parameter of heat transfer due to higher convective transport, with the maximum Nusselt number being achieved at Ra = 106 and ϕ = 0.05.