Among environmentally friendly energy sources, solar energy is one of the most widely used. Photovoltaic systems convert sunlight into electrical energy, forming the primary means of utilizing this energy source. However, the efficiency of PV systems decreases with rising temperatures. This study investigates the integration of phase change materials and water-cooled photovoltaic-thermal systems to enhance PV panel performance. The study consists of two stages, and both experiments were conducted in Antalya. In the first stage, the performance of PV panels integrated with PCMs having melting points of 25°C and 35°C was compared with standard PV panels. Results indicate that PCM integration improves thermal management and increases electrical efficiency. The PV-PCM35 system demonstrated a 21.3°C reduction in panel temperature under high-temperature conditions, leading to an average efficiency increase of 2.16%, with a maximum recorded increase of 3.72%. In the second stage, the performance of a water-cooled PV/T system integrated with PCM was compared to traditional PV systems. Findings reveal that the PV/T-PCM system provides significant improvements in electrical efficiency. The water cooling mechanism effectively dissipates heat, maintaining lower panel temperatures and enhancing efficiency. The PV/T-PCM system achieved a maximum electrical efficiency increase of 3.79% and a thermal efficiency increase of 62.74%. These results demonstrate the potential of PV/T-PCM systems to produce more efficient energy in hot regions, particularly in areas with high temperatures such as Antalya.