"When solar irradiation reaches a surface, some of it is absorbed while the rest is reflected. Part of the light absorbed by the surface transforms into heat and increases the module's temperature. Some of the thermal energy from the PV panel is lost to the environment through convection and thermal radiation. Therefore, for thermal losses, I have two equations: Q(radiation) and Q(convection). To introduce them as boundary conditions in Fluent, I used a Mixed approach to incorporate radiation and convection. However, I'm unsure how to apply the optical loss of the surface due to reflection of the panel towards the environment, derived as: Q_reflectance = G_sun * (1-α), as a boundary condition in Fluent applied to a wall.