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The cooling techniques of photovoltaic (PV) panels captured special attention due to positive impact on PV panels efficiency as continuous elevation of temperature degraded its performance. A number of studies have suggested the better prospects of air, water and phase change material (PCM) for thermal management of PV modules. The present work studies three different nanoparticle-based nano-PCMs for acceleration in performance of PV panel in terms of temperature reduction and increment of electrical efficiency. The experimental methodology was tested in the outdoor conditions of Taxila, Pakistan during winter seasons by using different concentrations (0.25 wt % and 0.5 wt % ) of multiwall carbon nanotubes nanoparticles, graphene nanoplatelets and magnesium oxide nanoparticles in phase change material (PT-58). The topmost performance of PV panel is found at 0.5 wt % nanomaterial concentration in graphene nanoplatelets/PT-58 nano-PCM. The experimental results indicate that maximum temperature reduction is observed to be 9.94 °C , 6.53 °C for PV/nano-PCM at 0.5 wt % of graphene nanoplatelets/PT-58 nano-PCM and 0.25 wt % of graphene nanoplatelets/PT-58 nano-PCM respectively while it was 5.01 °C for PV/PCM with highest observation in electrical efficiency of 12.10 % , 11.97 % and 11.74 % respectively as compared to conventional PV panel. The maximum percentage increase of electrical power was 33.07 % in case of GNPs/PT-58 nano-PCM at 0.5 wt % of nanomaterial in base PCM. The graphene nanoplatelets based nano-PCM exhibited best results in terms of temperature reduction as well as electrical efficiency and higher concentration of nanoparticles indicated good results compared to low concentration in nano-PCM.

The efficiency of photovoltaic (PV) panels plummet due to its escalating surface or operating temperature. Knowing this fact, the thermal regulation of PV panels is inevitable. Passive cooling techniques i.e. using phase change material (PCM) has gained attention in recent years for thermal regulation of PV panels. The present study investigates the performance of PV panels by varying thickness of hybrid PCMs in the climate of Taxila, Pakistan. The two PCMs having various melting points, kept apart by an aluminum plate were placed on rear side of PV module. The performance of three different configurations (B, C, D) of PV panels containing various thickness of hybrid PCMs was measured with respect to configuration A which was subjected to natural cooling. The PV panel configuration that has more amount of low melting point PCM as compared to other PCM showed better performance. It was witnessed that average reduction in temperature for configurations ‘B’, ‘C’ and ‘D’ were 4.9 °C, 6.5 °C and 8.1 °C respectively in comparison to configuration “A”. Also, increment of electrical efficiency for these three configurations were observed as 5.0%, 6.1% and 7.8% respectively due to enhancement in electrical power of PV panels. The configuration “D” having highest thickness of low melting PCM indicated best results in the sense of electrical power and electrical efficiency as compared to the other two configurations B and C having high melting PCMs.

The thermal regulation of photovoltaic (PV) modules is utmost necessary as temperature enhancement of PV panels deteriorates its conversion efficiency. Different studies have been done in the literature to regulate the temperature of module by using various fluids and materials which include air, water, nanofluids as well as phase change material (PCM). The current research studies four various types of PV configurations with the aim of enhancement in cell efficiency. These four configurations include reference panel, PV panel having only PCM, PV panel having PCM with foam of thickness 8 mm and PV panel having PCM along foam with 12 mm thickness. This is the novelty of the current research that PCM with foam have not studied yet in photovoltaic cooling. The PT58 and RT44 were used as phase change materials along with aluminum foam having 8 mm and 12 mm thickness. The experimentation was done under the environment of Taxila, Pakistan during the month of February. The maximum efficiency of PV module is found by the configuration having PCM with foam of 12 mm thickness. The result of experimentation depicts that reduction in maximum temperature by using RT44 along with foam was 11.21 °C for PV panel having only PCM, 20.95 °C for PV panel having PCM with foam of thickness 8 mm and 24.39 °C for PV panel having PCM along foam with 12 mm thickness with highest conversion efficiency 11.68 % , 11.79 % , 12.06 % respectively in comparison to naturally cooled PV module. Similarly, the lowering in temperature using PT/58 along with foam was 3.33 °C for PV panel having only PCM, 6.9 °C for PV panel having PCM with foam of thickness 8 mm and 9.03 °C for PV panel having PCM with foam of thickness 12 mm respectively having highest electrical efficiency 11.32 % , 11.50 % , 11.77 % respectively as compared to reference module. The increment in maximum percentage electrical power was 23.30 % for PV panel having RT44 PCM along foam with 12 mm thickness. The higher thickness of foam along with base phase change material depicted best results with maximum decrement in temperature of PV panel as well as maximum enhancement in conversion efficiency as compared to less value of foam thickness with base PCM. Therefore, this study is especially attractive to young researchers who are working in thermal management of photovoltaic.

Concentrated photovoltaics (CPV) is a dawn technology in the field of photovoltaic that helps in escalating the effective use of solar energy. Nowadays, applications of photovoltaic solar cells are catching attention due to the better utilization of solar energy. A huge amount of solar energy is received by the earth from the sun, but a barrier to the large-scale use of photovoltaic solar cells is their higher initial cost and lower conversion compared to other non-renewable energy systems. Concentrated Photovoltaics (CPV) is one of the vital tools that focus solar radiation on the small area of solar cells using optical devices to maximize solar to thermal conversion. Low cost, high efficiency, and climate-friendly are the main advantages of concentrated photovoltaics. The review study presents the outlook of work conducted worldwide on the different types of concentrated photovoltaics. In addition, the effect of various performance affecting parameters, challenges, and recent progress is also part of the study. Most of the CPV have efficiency up to 15 % while some have an efficiency range of 25–28 % which is still very low. It was found that the CPV gave maximum efficiency of up to 38.5 % at optimal solar radiation. The focus of sunlight on a small area of solar cell increases the temperature of concentrated photovoltaic allegedly pernicious for electrical efficiency and the life of CPV. Factors like direct normal irradiance, high cell temperature, soiling, optical design, reliability, and durability are considered as challenges and a concise summary of various studies on these challenges is presented. In this regard, various cooling techniques have been investigated by different researchers for thermal management of CPV systems which are discussed in detail. As CPV technology is still in the development phase, various new optical designs emphasizing novel designs and materials are also summarized in the current study. Finally, some recommendations are oriented which will be very valuable for those who are working or want to work in the field of photovoltaics.