Recent techniques for cooling of concentrated photovoltaic thermal systems

The energy conversion performance of commercial photovoltaic (PV) systems is only 15-20 percent; moreover, a rise in working temperature mitigates this low efficiency. To enhance their performance and prevent damage, researchers test new technologies and integrate heat recovery devices with PV systems. Concentrated photovoltaic systems (CPVs) are especially vulnerable to high radiation levels. This paper explores novel cooling techniques for PV systems, an area that has not been extensively investigated before. The cooling methods are categorized into front-surface and back-surface cooling methods, offering a unique perspective on how to keep PV systems cool. Moreover, the paper delves into the advancements made in PV cooling systems and CPVs, shedding light on the cutting-edge developments in this field. The results demonstrate the profound impact of various operational factors, such as radiation and wind speed, on the selection of suitable cooling systems or heat recovery methods. These findings unveil the crucial importance of considering these factors when choosing cooling techniques, adding a compelling dimension to the research. For example, it was depicted that optical cooling techniques can enhance the performance of PV systems by up to 4.2% and the solar-to-heat conversion efficiency by up to 47%. Furthermore, this research ventures into uncharted territory by subjecting both the front and back sides of the PV module to active and passive cooling techniques under differing work conditions. The comprehensive list provided here exhaustively describes the advantages, disadvantages, and developments of each technique, revealing the novelty of the approaches explored in this paper. It was reported that back cooling techniques can decline the cell temperature of PV systems by up to 57.8% and grow the electrical and thermal efficiencies by up to 82.6% and 97.75%, respectively. The groundbreaking nature of this research lies in its ability to empower decision-makers to select the optimal cooling system based on specific requirements and environmental factors, thereby bridging the gap between theory and practical application. The paper also introduces a new concept of cooling using hydrogel, a 3D porous network structure that can enhance photovoltaic energy conversion and storage, and reviews two recent studies that demonstrated the effectiveness of hydrogel cooling methods for PV panels. Moreover, the paper discusses the issue of dust deposition and mitigation, which affects the performance and lifetime of PV modules, and evaluates various methods for cleaning or reducing dust on PV panels, such as manual, passive, self-cleaning, and mechanical.