A solar photovoltaic (PV) system produces electrical energy from solar energy. This green, sustainable system has low energy conversion efficiency due to the rise in PV temperature throughout the day. In order to keep the temperature of the panels close to ambient, this study examines the usage of hydrated salt (HS36) as a Phase Change Material (PCM) for PV cooling. The primary goal of this experimental study is to cool the PV panel by introducing PCM behind the PV system (PV-PCM), thus increasing its performance. An energy and exergy performance assessment was carried out on PV and PV-PCM systems. The result indicates that placing a PCM over the back of the solar panel’s back reduced the operational temperature by 25.4% and increased the panel’s electrical efficiency by 17.5%. PV-PCM systems’ maximum exergy efficiency increased by 12.57%, and their exergy destruction ratio decreased by 12.49%. The proposed PV-PCM system with HS36 PCM increased the PV panel performance and can be deployed in the PV system.

Hybrid photovoltaic-thermal heat pump (PV/T-HP) solar energy systems are promising since they can achieve a system total efficiency greater than 80%. By maximizing the output of a PV/T system for simultaneous heating and cooling, this strategy can meet over 60% of urban households’ heating needs and around 40% of their cooling needs. In this work, a novel PV/T evaporator was designed, fabricated, and an aluminium foil encapsulated hydrated salt (HS36) PCM was integrated with the PV/T evaporator of the PV/T direct expansion heat pump system (PV/T-DXHP). Energy analysis was carried out on the PV/T-DXHP system with PCM in tropical climate regions of India for achieving net zero energy buildings. The experimental study revealed that the average PV electricity efficiency was 14.17%, which is near the PV panel’s STC value. The average thermal efficiency of the system was 104.38%, and the PV/T system’s average overall efficiency was 117.58%. The heating and cooling COPs of the system were 5.73 and 4.62, respectively. It was concluded that net-zero energy buildings are possible with the help of photovoltaic heat pump systems that use PCM and solar energy to make electricity, cool spaces, and heat water.

The design of solar concentrating collectors for the effective utilization of solar energy is a challenging condition due to tracking errors leading to different divergences of the solar incidence angle. To enhance the optical performance of solar parabolic trough collectors (SPTC) under a diverged solar incidence angle, an additional compound parabolic concentrator (CPC) is introduced as a secondary reflector. SPTC with CPC is designed and modeled for a single axis-tracking concentrating collector based on the local ambient conditions. In this work, the optical performance of the novel SPTC system with and without a secondary reflector is investigated using MATLAB and TRACEPRO software simulations for various tracking errors. The significance parameters such as the solar incidence angle, aperture length, receiver tube diameter, rim angle, concentration ratio, solar radiation, and absorbed flux are analyzed. The simulation results show that the rate of the absorbed flux on the receiver tube is significantly improved by providing the secondary reflector, which enhances the optical efficiency of the collector. It is found that the optical efficiency of the SPTC with a secondary reflector is 20% higher than the conventional collector system for a solar incidence angle of 2°. This work can effectively direct the choice of optimal secondary reflectors for SPTC under different design and operating conditions.