The main challenge associated with solar panels is the need to reduce excessive heat and optimize efficiency to achieve stable conditions. Therefore, a combination of collector and cooling technologies, such as Photovoltaic Thermal (PVT) Technology, is needed to address this problem. This research used water-based rectangular channel to cool the PVT through the Ansys simulation method. A total of nine variations of mass flow rates, which ranged from 0.001 to 0.009 kg/s and six solar intensities between 500 W/m2 and 1000 W/m2 were used to achieve the optimal performance. An energetic analytical method with average Sustainability Index (SI) of 0.001-0.009 kg/s and 1.186 at 1000 W/m2 intensity were incorporated. Furthermore, the maximum average Waste Exergy Rasio (WER) value of 0.854 at a 500 W/m2 intensity was used to determine the flow rate. The highest average Exergetic Ecological Index (EcEI) value recorded was -0.687 at a 1000 W/m2 radiation intensity, while the highest average Improvement Potential (IP) value was 421.145 W. The results showed that the simulation serve as a valuable point of reference in the design and advancement of water-based rectangular channel within future PVT technology.