Advanced PV/T systems are introduced and explained in detail, in this chapter. The concepts of no... more Advanced PV/T systems are introduced and explained in detail, in this chapter. The concepts of novel base fluids such as nanofluids and their application in PV/T systems are described. Nanofluid-based PV/T systems are introduced, along with nanofluid preparation, mixing, and thermophysical property tests. The concept and methodology of the two-step method for preparing nanofluids to be used in cooling of PV modules is illustrated and supported by literature review. Comprehensive literature review on nanofluid-based PV/T systems was conducted to view nanofluids in flat-plate collectors (FPC), spectral splitting (PV/T) collectors, and spectral selective nanofluids and jet impingement (PV/T) collectors and, furthermore, the various advanced types of nanofluids, such as carbon nanotubes (CNT)-based PV/T, low-concentrated PV/T collectors, hybrid photovoltaic thermoelectric systems with nanofluids, phase change material (PCM), and nano-PCM-based PV/T systems. Furthermore, an introduction to grid-connected PV systems in terms of elements, design considerations, and technical calculations of specific yield, capacity factor, performance ratio, etc. The use of artificial neural networks (ANN) to predict the performance of PV/T collectors was also introduced and explained, followed by brief description of applications of PV/T systems.
The core of the book is to explain the theory and applications of Photovoltaic Thermal (PV/T) col... more The core of the book is to explain the theory and applications of Photovoltaic Thermal (PV/T) collectors which is provided in this chapter. The concepts and components of PV/T are illustrated as well as energy efficiency calculations. The case for using PV/T collectors is stated and followed by the rationale in terms of the combined efficiency per unit area and the cost-effectiveness of this technology. An overview with description of the chronology of PV/T and classifications is provided. In addition, the main aim and various design considerations were discussed for optimum design and testing of PV/T systems. Electrical and thermal analysis of PV/T collectors for different parameters was investigated through a brief literature review. While extensive literature review was carried out to explain the various aspects of passive PV cooling systems and different classifications of PV/T collectors which include air-based, water-based, air- and water-based, refrigerant-based PV/T collecto...
PV/T collectors are hybrid units combining both photovoltaic (PV) modules and solar thermal colle... more PV/T collectors are hybrid units combining both photovoltaic (PV) modules and solar thermal collectors to generate electrical and thermal energy simultaneously. The thermal collector generates heat and provides cooling for the PV concurrently. PV/T design and development face many hurdles and issues that must be addressed. This chapter provides the conclusions and recommendations of this book. Conclusions are made as statements for various aspects of PV/T systems such as their technical design, performance, and evaluation criteria. The recommendations for future work are provided to help the research in this field to move forward. Hence, future works are recommended based on types of studies to original work, case studies, review articles, replication studies, and collaborations. Furthermore, the chapter presents the main hurdles and issues associated with the field of PV/T and displayed them as problem statements which are classified to technical challenges, economic challenges, social awareness challenges, and policy and regulation challenges. Furthermore, the chapter displays points of contention and debate in the field. Finally, the authors’ expectations of PV/T technology development are laid out.
Discussion of economic aspects of any technology is critical to establish its utility and market ... more Discussion of economic aspects of any technology is critical to establish its utility and market potential. Given that PV/T is used as an energy source, it must be cost-competitive with conventional renewable energy and fossil fuel sources. For research and development to understand and evaluate the economic aspect of PV/T systems, it is recommended to study factors such as life cycle cost analysis (LCCA). This chapter presents the LCCA and shows how to use the method in research, by calculating parameters such as life cycle cost (LCC), cost of energy (COE), etc., as provided in other works. The levelized cost of heat (LCOH) is introduced to view the economics of the thermal aspect, given that PV/T generates heat as well. Moreover, the levelized cost of energy (LCOE) is explained in terms of concept and method of calculation and briefly reviewed in different research works. To assess the environmental impacts which can be linked to economic aspects in some cases, the life cycle assessment (LCA) is introduced. Finally, the payback period (PBP) is explained in concept and briefly discussed in terms of its utility and disadvantages.
The temperature of photovoltaic cell is reduced by heat transfer fluids (HTF) in cooling channels... more The temperature of photovoltaic cell is reduced by heat transfer fluids (HTF) in cooling channels, which are attached to the back of the photovoltaic module in a hybrid thermal photovoltaic system (PV/T). Recently, nanofluids have been implemented as HTF's in PV/T systems. Various types of nanofluids have been synthesized, prepared, and tested, however, not a specific type in particular. In this paper, experiments were carried out using Single‐walled carbon nanotubes (SWCNTs) nanofluids. The proposed nanofluid consisted of a primary fluid that is water with a volume ratio of 75.0% and glycol Ethylene with a volume ratio of 25% and a surfactant, Cetyltrimethylammonium Bromide(CTAB), in an amount of 0.5 mL. Single‐walled carbon nanotubes (SWCNTs) were added in four weight ratios of 0.1%, 0.5%, 1.0%, and 2.0%. The samples were examined and compared based on their thermophysical properties, and from these properties, a volume fraction of 0.5% SWCNT was chosen to form the nanofluid. In this study, the performance characteristics of the PV/T were investigated. The results of the study showed that the proposed nanofluid caused an increase in the electrical power generated by 11.7% while the electrical efficiency of PV/T was increased up to 25.2% compared to the PV system. It is found that the cell temperature reduced by 18% on average for a whole day operation. The studied PV/T system produced an impressive overall efficiency of 71% compared to the PV system, which generated no more than 11%. SWCNTs have shown superior results in improving the performance of the studied PV/T system compared to other types of nanofluids used in PV/T systems in the literature.
The use of photovoltaics has spread widely, and government agencies have begun adopting plans to ... more The use of photovoltaics has spread widely, and government agencies have begun adopting plans to deploy plants with large capacities, due to their environmental friendliness, low manufacturing costs, and high productivity. In the sunny countries where this technology should spread, the photovoltaics' energy conversion efficiency decreases due to the high temperature of which the cell's operate at; because a large part of the solar radiation is absorbed by the solar panels as heat, while the smaller part converts it to electricity. From here, the benefit of the shift towards the PV/T technology that works to reduce the photovoltaic modules temperature and improve their electricity produced along with yielded thermal energy which can be utilized in other applications. In this study, a thorough review of many recent research and studies published in the field of PV/T has been carried out. The present study was divided into several sections to clarify and focus on the effect of each technology separately. Researchers used one or more fluids to cool the solar panels, and their research dealt with many of these fluids, starting with air, water, oil, etc. Other researchers have tended to increase the thermal conductivity of liquid cooling fluids by adding many types of nanoparticles with high thermal conductivity. Other researchers have used variable‐phase materials to take advantage of the large storage of the latent heat of these materials. Other researchers have studied improving heat transfer of PCMs by mixing it with nanomaterials with high thermal conductivity. Others have also combined nano‐PCMs and nanofluids together in one system, and they have demonstrated, in theory and practice, that this technique exhibits higher energy collection and utilization than the other types of PV/T. At the conclusion of the study, some critical points are identified that work is still limited and needs more research efforts and studies.
This chapter provides a description of the current state of the global solar thermal industry and... more This chapter provides a description of the current state of the global solar thermal industry and market along with future possibilities of research and development in the PV/T industry. An outline for the criteria of technical, economic, and environmental performance of PV/T systems is laid out. Various conventional and novel designs of PV/T systems are revisited and studied as theoretical and practical studies. The various configurations of PV/T collectors such as grid-connected PV/T (GCPV/T) and building-integrated PV/T (BIPV/T) are discussed as well. Commercial and industrial solutions and initiative are PV and PV/T systems which are discussed with emphasis on examining the difficulties and barriers associated with delay of PV/T proliferation. Finally, the commercial PV/T products, and PV/T applications, installed by different companies are displayed.
The dynamic behavior of photovoltaics is attributed to their dependence on solar irradiance level... more The dynamic behavior of photovoltaics is attributed to their dependence on solar irradiance levels and their material characteristics which makes them highly affected by temperature gain or loss. This chapter discusses the different climatic conditions that affect PV and PV/T systems such as solar irradiance, ambient temperature, wind speed, humidity, and dust. Each parameter is explained in terms of concept, type, and level of impact on PV/T. The impact is measured through observing changes in the electrical and thermal parameters of PV/T collectors such as power, electrical efficiency, thermal efficiency, and overall PV/T efficiency. Assessing PV/T collector behavior with respect to the environment around it intelligently deals with each issue to maximize the output of PV/T systems and choose suitable locations for installation. In addition, accurate assessment of the technology’s reliability can be made with knowledge of various parameters affecting its performance.
Today, photovoltaic modules have become accepted by the public and scientists in the production o... more Today, photovoltaic modules have become accepted by the public and scientists in the production of clean electricity and as a possible alternative to electricity produced from fossil fuels. These modules suffer from a deterioration in their electrical efficiency as a result of their high temperature. Several researchers have proposed the use of high-efficiency hybrid photovoltaic (PV/T) systems that can cool PV modules and also produce hot water. Improving the PV modules’ electrical efficiency increases the investment attraction and commercialization of this technology. The possibility of restoring the electrical efficiency of the photovoltaic panel that was lost due to its high temperature was investigated in this study. A PV/T system designed to operate with a paraffin-filled thermal tank attached to the PV module was used. Inside the paraffin is a heat exchanger that circulates inside a nanofluid. This design is adopted to cool down the PV module temperature. The study was carried out in the climatic conditions of the month of May in the city of Baghdad - Iraq. The proposed PV/T system’s electrical efficiency was compared with similar systems from the literature. The proposed system has achieved an obvious enhancement as its electrical efficiency was 13.7%.
The thermal conductivity and stability of any nanofluid are essential thermophysical properties. ... more The thermal conductivity and stability of any nanofluid are essential thermophysical properties. These properties are affected by many parameters, such as the nanoparticles, the base fluid, the surfactant, and the sonication time used for mixing. In this study, multi-walled carbon nanotubes (MWCNTs) were selected as additive particles, and the remaining variables were tested to reach the most suitable nanofluid that can be used to cool photovoltaic/thermal (PVT) systems operating in the harsh summer conditions of the city of Baghdad. Among the tested base fluids, water was chosen, although ethylene glycol (EG), propylene glycol (PG), and heat transfer oil (HTO) were available. The novelty of the current study contains the optimization of nanofluid preparation time to improve MWCNTs’ PVT performance with different surfactants (CTAB, SDS, and SDBS) and base fluids (water, EG, PG, and oil). When 1% MWCNT mass fraction was added, the thermal conductivity (TC) of all tested fluids increa...
Advanced PV/T systems are introduced and explained in detail, in this chapter. The concepts of no... more Advanced PV/T systems are introduced and explained in detail, in this chapter. The concepts of novel base fluids such as nanofluids and their application in PV/T systems are described. Nanofluid-based PV/T systems are introduced, along with nanofluid preparation, mixing, and thermophysical property tests. The concept and methodology of the two-step method for preparing nanofluids to be used in cooling of PV modules is illustrated and supported by literature review. Comprehensive literature review on nanofluid-based PV/T systems was conducted to view nanofluids in flat-plate collectors (FPC), spectral splitting (PV/T) collectors, and spectral selective nanofluids and jet impingement (PV/T) collectors and, furthermore, the various advanced types of nanofluids, such as carbon nanotubes (CNT)-based PV/T, low-concentrated PV/T collectors, hybrid photovoltaic thermoelectric systems with nanofluids, phase change material (PCM), and nano-PCM-based PV/T systems. Furthermore, an introduction to grid-connected PV systems in terms of elements, design considerations, and technical calculations of specific yield, capacity factor, performance ratio, etc. The use of artificial neural networks (ANN) to predict the performance of PV/T collectors was also introduced and explained, followed by brief description of applications of PV/T systems.
The core of the book is to explain the theory and applications of Photovoltaic Thermal (PV/T) col... more The core of the book is to explain the theory and applications of Photovoltaic Thermal (PV/T) collectors which is provided in this chapter. The concepts and components of PV/T are illustrated as well as energy efficiency calculations. The case for using PV/T collectors is stated and followed by the rationale in terms of the combined efficiency per unit area and the cost-effectiveness of this technology. An overview with description of the chronology of PV/T and classifications is provided. In addition, the main aim and various design considerations were discussed for optimum design and testing of PV/T systems. Electrical and thermal analysis of PV/T collectors for different parameters was investigated through a brief literature review. While extensive literature review was carried out to explain the various aspects of passive PV cooling systems and different classifications of PV/T collectors which include air-based, water-based, air- and water-based, refrigerant-based PV/T collecto...
PV/T collectors are hybrid units combining both photovoltaic (PV) modules and solar thermal colle... more PV/T collectors are hybrid units combining both photovoltaic (PV) modules and solar thermal collectors to generate electrical and thermal energy simultaneously. The thermal collector generates heat and provides cooling for the PV concurrently. PV/T design and development face many hurdles and issues that must be addressed. This chapter provides the conclusions and recommendations of this book. Conclusions are made as statements for various aspects of PV/T systems such as their technical design, performance, and evaluation criteria. The recommendations for future work are provided to help the research in this field to move forward. Hence, future works are recommended based on types of studies to original work, case studies, review articles, replication studies, and collaborations. Furthermore, the chapter presents the main hurdles and issues associated with the field of PV/T and displayed them as problem statements which are classified to technical challenges, economic challenges, social awareness challenges, and policy and regulation challenges. Furthermore, the chapter displays points of contention and debate in the field. Finally, the authors’ expectations of PV/T technology development are laid out.
Discussion of economic aspects of any technology is critical to establish its utility and market ... more Discussion of economic aspects of any technology is critical to establish its utility and market potential. Given that PV/T is used as an energy source, it must be cost-competitive with conventional renewable energy and fossil fuel sources. For research and development to understand and evaluate the economic aspect of PV/T systems, it is recommended to study factors such as life cycle cost analysis (LCCA). This chapter presents the LCCA and shows how to use the method in research, by calculating parameters such as life cycle cost (LCC), cost of energy (COE), etc., as provided in other works. The levelized cost of heat (LCOH) is introduced to view the economics of the thermal aspect, given that PV/T generates heat as well. Moreover, the levelized cost of energy (LCOE) is explained in terms of concept and method of calculation and briefly reviewed in different research works. To assess the environmental impacts which can be linked to economic aspects in some cases, the life cycle assessment (LCA) is introduced. Finally, the payback period (PBP) is explained in concept and briefly discussed in terms of its utility and disadvantages.
The temperature of photovoltaic cell is reduced by heat transfer fluids (HTF) in cooling channels... more The temperature of photovoltaic cell is reduced by heat transfer fluids (HTF) in cooling channels, which are attached to the back of the photovoltaic module in a hybrid thermal photovoltaic system (PV/T). Recently, nanofluids have been implemented as HTF's in PV/T systems. Various types of nanofluids have been synthesized, prepared, and tested, however, not a specific type in particular. In this paper, experiments were carried out using Single‐walled carbon nanotubes (SWCNTs) nanofluids. The proposed nanofluid consisted of a primary fluid that is water with a volume ratio of 75.0% and glycol Ethylene with a volume ratio of 25% and a surfactant, Cetyltrimethylammonium Bromide(CTAB), in an amount of 0.5 mL. Single‐walled carbon nanotubes (SWCNTs) were added in four weight ratios of 0.1%, 0.5%, 1.0%, and 2.0%. The samples were examined and compared based on their thermophysical properties, and from these properties, a volume fraction of 0.5% SWCNT was chosen to form the nanofluid. In this study, the performance characteristics of the PV/T were investigated. The results of the study showed that the proposed nanofluid caused an increase in the electrical power generated by 11.7% while the electrical efficiency of PV/T was increased up to 25.2% compared to the PV system. It is found that the cell temperature reduced by 18% on average for a whole day operation. The studied PV/T system produced an impressive overall efficiency of 71% compared to the PV system, which generated no more than 11%. SWCNTs have shown superior results in improving the performance of the studied PV/T system compared to other types of nanofluids used in PV/T systems in the literature.
The use of photovoltaics has spread widely, and government agencies have begun adopting plans to ... more The use of photovoltaics has spread widely, and government agencies have begun adopting plans to deploy plants with large capacities, due to their environmental friendliness, low manufacturing costs, and high productivity. In the sunny countries where this technology should spread, the photovoltaics' energy conversion efficiency decreases due to the high temperature of which the cell's operate at; because a large part of the solar radiation is absorbed by the solar panels as heat, while the smaller part converts it to electricity. From here, the benefit of the shift towards the PV/T technology that works to reduce the photovoltaic modules temperature and improve their electricity produced along with yielded thermal energy which can be utilized in other applications. In this study, a thorough review of many recent research and studies published in the field of PV/T has been carried out. The present study was divided into several sections to clarify and focus on the effect of each technology separately. Researchers used one or more fluids to cool the solar panels, and their research dealt with many of these fluids, starting with air, water, oil, etc. Other researchers have tended to increase the thermal conductivity of liquid cooling fluids by adding many types of nanoparticles with high thermal conductivity. Other researchers have used variable‐phase materials to take advantage of the large storage of the latent heat of these materials. Other researchers have studied improving heat transfer of PCMs by mixing it with nanomaterials with high thermal conductivity. Others have also combined nano‐PCMs and nanofluids together in one system, and they have demonstrated, in theory and practice, that this technique exhibits higher energy collection and utilization than the other types of PV/T. At the conclusion of the study, some critical points are identified that work is still limited and needs more research efforts and studies.
This chapter provides a description of the current state of the global solar thermal industry and... more This chapter provides a description of the current state of the global solar thermal industry and market along with future possibilities of research and development in the PV/T industry. An outline for the criteria of technical, economic, and environmental performance of PV/T systems is laid out. Various conventional and novel designs of PV/T systems are revisited and studied as theoretical and practical studies. The various configurations of PV/T collectors such as grid-connected PV/T (GCPV/T) and building-integrated PV/T (BIPV/T) are discussed as well. Commercial and industrial solutions and initiative are PV and PV/T systems which are discussed with emphasis on examining the difficulties and barriers associated with delay of PV/T proliferation. Finally, the commercial PV/T products, and PV/T applications, installed by different companies are displayed.
The dynamic behavior of photovoltaics is attributed to their dependence on solar irradiance level... more The dynamic behavior of photovoltaics is attributed to their dependence on solar irradiance levels and their material characteristics which makes them highly affected by temperature gain or loss. This chapter discusses the different climatic conditions that affect PV and PV/T systems such as solar irradiance, ambient temperature, wind speed, humidity, and dust. Each parameter is explained in terms of concept, type, and level of impact on PV/T. The impact is measured through observing changes in the electrical and thermal parameters of PV/T collectors such as power, electrical efficiency, thermal efficiency, and overall PV/T efficiency. Assessing PV/T collector behavior with respect to the environment around it intelligently deals with each issue to maximize the output of PV/T systems and choose suitable locations for installation. In addition, accurate assessment of the technology’s reliability can be made with knowledge of various parameters affecting its performance.
Today, photovoltaic modules have become accepted by the public and scientists in the production o... more Today, photovoltaic modules have become accepted by the public and scientists in the production of clean electricity and as a possible alternative to electricity produced from fossil fuels. These modules suffer from a deterioration in their electrical efficiency as a result of their high temperature. Several researchers have proposed the use of high-efficiency hybrid photovoltaic (PV/T) systems that can cool PV modules and also produce hot water. Improving the PV modules’ electrical efficiency increases the investment attraction and commercialization of this technology. The possibility of restoring the electrical efficiency of the photovoltaic panel that was lost due to its high temperature was investigated in this study. A PV/T system designed to operate with a paraffin-filled thermal tank attached to the PV module was used. Inside the paraffin is a heat exchanger that circulates inside a nanofluid. This design is adopted to cool down the PV module temperature. The study was carried out in the climatic conditions of the month of May in the city of Baghdad - Iraq. The proposed PV/T system’s electrical efficiency was compared with similar systems from the literature. The proposed system has achieved an obvious enhancement as its electrical efficiency was 13.7%.
The thermal conductivity and stability of any nanofluid are essential thermophysical properties. ... more The thermal conductivity and stability of any nanofluid are essential thermophysical properties. These properties are affected by many parameters, such as the nanoparticles, the base fluid, the surfactant, and the sonication time used for mixing. In this study, multi-walled carbon nanotubes (MWCNTs) were selected as additive particles, and the remaining variables were tested to reach the most suitable nanofluid that can be used to cool photovoltaic/thermal (PVT) systems operating in the harsh summer conditions of the city of Baghdad. Among the tested base fluids, water was chosen, although ethylene glycol (EG), propylene glycol (PG), and heat transfer oil (HTO) were available. The novelty of the current study contains the optimization of nanofluid preparation time to improve MWCNTs’ PVT performance with different surfactants (CTAB, SDS, and SDBS) and base fluids (water, EG, PG, and oil). When 1% MWCNT mass fraction was added, the thermal conductivity (TC) of all tested fluids increa...
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