Cooling photovoltaic (PV) panels is essential for maintaining their electrical performance at optimal levels. Photovoltaic-thermal (PVT) technology, which is a hybrid system of PV cells and thermal loops, is widely used in which the PV panel can be cooled through the channel. In addition, wavy surfaces can improve heat transfer between the working fluid and the wall of the channel due to increasing turbulence intensity and improving the mixing of fluid flows. As a result, in this study, the impacts of the variation of solar heat flax and ambient temperature on the electrical efficiency and the thermal performance of a PVT applying wavy channels under certain wavelength and amplitude ratios and Reynolds number are investigated. The total efficiency of the PVT including a wavy channel has an increase of 14.8% with the increase in the surrounding temperature from 28 oC to 38 oC, while the power generation efficiency decreases from 10.5% to 10.3%. Results of numerical simulations demonstrated that both solar irradiation intensity and ambient temperature are highly impactful in the performance of the wavy channels in the cooling of the PVT cells and thus affecting their power generation and total efficiencies.