An evaluation of the performance of the Iraqi environments in terms of electrical, thermal and exergy efficiency is introduced in this study. The research is carried out in May 2022, in the Baghdad metropolis. The extraction process of heat from the photovoltaic units which arises from the coolant liquid mass flow rate deem as an essential point. The experimental studies were implemented by absorbing heat energy behind from the photovoltaic cell's surface in insulated conditions and using a cooled water unit. The results indicated that at a mass inflow rate of 0.2 kg/sec, the maximum average total efficiency of the system was recorded 22%. As a result, it is advised that to reduce the payback interval, it is possible to design efficient solar photovoltaic–thermal systems to promote the whole system's efficiency and lower the payback interval.