Search Results (69)

The aim of this study was the hydrothermal leaching of silver from waste monocrystalline silicon (m-Si) and polycrystalline silicon (p-Si) photovoltaic panel (PV) cells using organic acids, namely oxalic acid (OA) and citric acid (CA). Before leaching, two different pretreatment procedures were applied. First, the fluoropolymer backsheet was manually removed from the panel pieces and, then, the samples were subjected to high-temperature heating for the thermal degradation of the ethylene vinyl acetate (EVA) polymer. When removal by hand was not feasible, the second pretreatment procedure was followed by toluene immersion to remove the EVA and backsheet and separate the cells, glass, and films. After pretreatment, 4 M HCl leaching was applied to remove the aluminum layer from the cells. The remaining cells were subjected to hydrothermal leaching with organic acids to extract the silver. Several hydrothermal parameters were investigated, such as acid concentration (1-1.5-2 M), processing time (60-105-150 min), and temperature (150-180-210 °C), while the liquid-to-solid (L/S) ratio was fixed at 30 mL: 1 g, based on preliminary tests. Response surface methodology (RSM) was applied to optimize the hydrothermal leaching parameters. The optimized parameters were 210 °C, 95 min, 2 M CA or 210 °C, 60 min, 1 M OA. OA was more effective in Ag leaching than CA. The results were compared to HNO₃ leaching. The green leaching of silver from end-of-life PV panels with organic acids is an environmentally beneficial route. Full article

Solar photovoltaic (PV) technology has emerged as the most preferred source of clean energy generation and has been deployed at a large scale. However, end-of-life management of the PV modules is a critical issue that has garnered the recent attention of lawmakers and researchers alike. Consequently, several researchers are actively developing technology to recycle the end-of-life PV modules. Since silicon PV modules account for more than 90% of the modules deployed globally, most of these efforts are focused on recycling crystalline silicon PV modules. Researchers have primarily focused on recovering pure silver from the contacts and pure Si from the solar cells. However, to ensure complete recyclability of such panels, the different polymers used in these modules must also be recycled. This review addresses the issue of recycling the polymers from end-of-life c-Si modules. Scopus and Google Scholar were used to search for the relevant literature. This review presents the current state-of-the-art technology related to polymer recycling found in the PV modules, the challenges encountered in their recycling, and the outlook. While research on the recycling of polymers has progressed in the last few decades, the instances of their applications in the recycling of polymers from PV panels are rarely reported in the literature. In this work, certain technical pathways, which can be employed to recycled polymers obtained from end-of-life PV panels, are presented. Recycling the polymers from the end-of-life silicon PV modules is crucial for improving the sustainability of solar PV technology. Full article

Solar photovoltaic (PV) technology is developing quickly due to the continual rise in demand for energy and environmental protection. Solar thermal photovoltaic (STPV) systems can break the Shockley–Queisser limit of conventional PV systems by reshaping the solar spectrum using selective absorbers and emitters. However, the traditional design method relies on the designer’s experience, which fails to achieve rapid designing of STPV devices and greatly improve the performance. In this paper, an STPV thin-film selective emitter is inversely designed based on a genetic algorithm. The optimized structure consists of SiO₂ and SiC layers alternately stacked on a Cr substrate, whose emissivity can reach 0.99 at 1.86 μm. When combined with an InGaAsSb cell, the power conversion efficiency can be up to 43.3% at 1673 K. This straightforward and easily scalable film emitter can be designed quickly and gain excellent efficiency, which promotes the practical application of STPV systems. Full article

Flexibility, light weight, and mechanical robustness are the key advantages of flexible photovoltaic (PV) modules, making them highly versatile for sustainable energy solutions. Unlike traditional rigid PV modules, their flexible nature makes them incredibly versatile for harnessing energy in places where doing so was once impossible. They have a wide range of applications due to their flexibility and moldability, making it possible to conform these modules to surfaces like curved rooftops and other irregular structures. In this paper, we provide a comprehensive review of all the materials used in flexible PV modules with a focus on their role in sustainability. We thoroughly discuss the active-layer materials for crystalline silicon (c-Si)-based solar cells (SC) and thin-film solar cells such as cadmium telluride (CdTe), as well as copper indium gallium diselenide (CIGS), amorphous thin-film silicon (a-Si), perovskite and organic solar cells. Various properties, such as the optical, barrier, thermal, and mechanical properties of different substrate materials, are reviewed. Transport layers and conductive electrode materials are discussed with a focus on emerging trends and contributions to sustainable PV technology. Various fabrication techniques involved in making flexible PV modules, along with advantages, disadvantages, and future trends, are highlighted in the paper. The commercialization of flexible PV is also discussed, which is a crucial milestone in advancing and adapting new technologies in the PV industry with a focus on contributing toward sustainability. Full article

Bifacial photovoltaic (PV) modules can capture both front and rear incident light simultaneously, thereby enhancing their power output. Achieving uniformity in rear incident light is crucial for an efficient and a stable operation. In this study, we present a simple, yet effective textured rear reflector, designed to optimize the performance and stability of bifacial PV modules. The three-dimensional textured surface was created using an ethylene vinyl acetate sheet (EVA) through a hot-press method at 150 °C. Subsequently, the textured EVA surface was coated with solution-processed silver ink, increasing the reflectance of the textured reflector through a low-temperature process. The integration of the developed textured rear reflector into bifacial crystalline silicon (c-Si) PV modules resulted in an additional 6.9% improvement in power conversion efficiency compared to bifacial PV modules without a rear reflector, particularly when the rear reflector is close to the PV module. Furthermore, the textured rear reflector may mitigate current mismatch among cells by randomizing incident light and uniformly redistributing the reflected light to the PV cells. Consequently, the proposed textured reflector contributes to the enhanced performance and stability of bifacial PV modules. Full article

Modules based on c-Si cells account for more than 90% of the photovoltaic capacity installed worldwide, which is why the analysis in this paper focusses on this cell type. This study provides an overview of the current state of silicon-based photovoltaic technology, the direction of further development and some market trends to help interested stakeholders make decisions about investing in PV technologies, and it can be an excellent incentive for young scientists interested in this field to find a narrower field of research. This analysis covers all process steps, from the production of metallurgical silicon from raw material quartz to the production of cells and modules, and it includes technical, economic and environmental aspects. The economic aspect calls for more economical production. The ecological aspect looks for ways to minimise the negative impact of cell production on the environment by reducing emissions and using environmentally friendly materials. The technical aspect refers to the state of development of production technologies that contribute to achieving the goals of the economic, environmental and sustainability-related aspects. This involves ways to reduce energy consumption in all process steps, cutting ingots into wafers with the smallest possible cutting width (less material waste), producing thin cells with the greatest possible dimensional accuracy, using cheaper materials and more efficient production. An extremely important goal is to achieve the highest possible efficiency of PV cells, which is achieved by reducing cell losses (optical, electrical, degradation). New technologies in this context are Tunnel Oxide Passivated Contact (TOPcon), Interdigitated Back Contact Cells (IBCs), Heterojunction Cells (HJTs), Passivated Emitter Rear Totally Diffused cells (PERTs), silicon heterojunction cells (SHJs), Multi-Bush, High-Density Cell Interconnection, Shingled Cells, Split Cells, Bifacial Cells and others. The trend is also to increase the cell size and thus increase the output power of the module but also to reduce the weight of the module per kW of power. Research is also focused to maximise the service life of PV cells and minimise the degradation of their operating properties over time. The influence of shade and the increase in cell temperature on the operating properties should preferably be minimised. In this context, half-cut and third-cut cell technology, covering the cell surface with a layer that reduces soiling and doping with gallium instead of boron are newer technologies that are being applied. All of this leads to greater sustainability in PV technology, and solar energy becomes more affordable and necessary in the transition to a “green” economy. Full article

Concentrator photovoltaics (CPVs) have demonstrated high electrical efficiencies and technological potential, especially when deployed in CPV–thermal (CPV-T) hybrid absorbers, in which the cells’ waste heat can be used to power industrial processes. However, the high cost of tracking systems and the predominant use of expensive multi-junction PV cells have caused the market of solar co-generation technologies to stall. This paper describes the development and testing of a low-cost alternative CPV cell based on crystalline silicone (c-Si) for use in a novel injection-molded parabolic hybrid solar collector, generating both, photovoltaic electricity and thermal power. The study covers two different c-Si cell technologies, namely, passive emitter rear contact (PERC) and aluminum back surface field (Al-BSF). Simulation design and manufacturing are described with special attention to fingerprinting in order to achieve high current carrying capacities for concentrated sunlight. It was determined that Al-BSF cells offer higher efficiencies than PERC for the considered use case. Solar simulator tests showed that the highly doped 4 cm² cells (50 ohm/sq) reach efficiencies of 16.9% under 1 sun and 13.1% under 60 suns at 25 °C with a temperature coefficient of −0.069%(Abs)/K. Finally, options to further improve the cells are discussed and an outlook is given for deployment in a field-testing prototype. Full article

This study proposes a rectangular-shaped optical module capable of simultaneously implementing crop cultivation and solar power generation. By employing a cylindrical Fresnel lens (CFL) array plate with a size of 100 × 100 mm², multiple focal lines are formed, where some of the incident light transmits through the module while the rest is guided laterally through the rectangular lightguide structure. This guided sunlight is then concentrated by a cylindrical compound parabolic concentrator (CCPC) structure, resulting in a 20-fold concentration ratio, onto a 5 × 100 mm² Si photovoltaic (PV) cell. To experimentally verify feasibility, both the CFL array plate and the lightguide plate were fabricated with three-axis machine tooling equipment and assembled. The power generated experimentally by the 5 × 100 mm² Si PV cell was 54% of the expected value from the simulation results on the light-concentrated efficiency considering experimental conditions, while the results on experimental transmittance along with rotation angles were very close to the simulation results. However, overall, the tendency of the generated power along the rotation angles is close to the tendency of the light-concentrated efficiency along the rotation angles from the simulation. Additionally, this study dealt with further consideration to enhance light-concentrated efficiency, introducing a means to adjust the trade-off relationship between transmittance and light-concentrated efficiency. Full article

Thin-film solar cells have been referred to as second-generation solar photovoltaics (PV) or next-generation solutions for the renewable energy industry. The layer of absorber materials used to produce thin-film cells can vary in thickness, from nanometers to a few micrometers. This is much thinner than conventional solar cells. This review focuses on inorganic thin films and, therefore, hybrid inorganic–organic perovskite, organic solar cells, etc., are excluded from the discussion. Two main families of thin-film solar cells, i.e., silicon-based thin films (amorphous (a-Si) and micromorph silicon (a-Si/c-Si), and non-silicon-based thin films (cadmium telluride (CdTe) and copper–indium–gallium diselenide (CIGS)), are being deployed on a commercial scale. These commercial technologies, until a few years ago, had lower efficiency values compared to first-generation solar PV. In this regard, the concept of driving enhanced performance is to employ low/high-work-function metal compounds to form asymmetric electron and hole heterocontacts. Moreover, there are many emerging thin-film solar cells conceived to overcome the issue of using non-abundant metals such as indium (In), gallium (Ga), and tellurium (Te), which are components of the two commercial thin-film technologies, and therefore to reduce the cost-effectiveness of mass production. Among these emerging technologies are kesterite CZTSSE, intensively investigated as an alternative to CIGS, and Sb₂(S,Se)₃. In this review, after a general overview of the current scenario of PV, the three main challenges of inorganic thin-film solar cells, i.e., the availability of (safe) metals, power conversion efficiency (PCE), and long-term stability, are discussed. Full article

This study employs a life cycle assessment (LCA) approach to investigate the environmental burden of photovoltaic power generation systems that use multi-crystalline silicon (multi-Si) modules in Pakistan. This study evaluates the energy payback time (EPBT) of this class of systems, and considers various environmental impacts, including climate change, acidification, and eutrophication. The assessment accounts for upstream, midstream, and downstream processes, including cell as well as module production. The critical stages in the production cycle were identified, including the metallic silicon transformation into solar silicon and the assembly of the panels, which involve energy-intensive materials such as aluminum frames and glass roofing. Despite using the most efficient conversion technology, the former stage consumes a significant amount of electricity. This study reveals that multi-Si PV systems in Pakistan have an EPBT that is considerably less than their lifespan, ranging from 2.5 to 3.5 years. These findings suggest that the development of PV systems in Pakistan is a very interesting option for energy production. Additionally, this study compares solar PV and wind power generation systems in various regions of Pakistan. The study outcomes can facilitate evidence-based decision-making processes in the renewable energy sector and contribute significantly to Pakistan’s endeavor to transition toward a sustainable energy system. Full article

Photovoltaic systems have become more attractive alternatives to be integrated into electrical power systems. Therefore, PV cells have gained immense interest in studies related to their operation. A photovoltaic module’s performance can be optimized by identifying the parameters of a photovoltaic cell to understand its behavior and simulate its characteristics from a given mathematical model. This work aims to extract and identify the parameters of photovoltaic cells using a novel metaheuristic algorithm named Modified Social Group Optimization (MSGO). First, a comparative study was carried out based on various technologies and models of photovoltaic modules. Then, the proposed MSGO algorithm was tested on a monocrystalline type of panel with its single-diode and double-diode models. Then, it was tested on an amorphous type of photovoltaic cell (hydrogenated amorphous silicon (a-Si: H)). Finally, an experimental validation was carried out to test the proposed MSGO algorithm and identify the parameters of the polycrystalline type of panel. All obtained results were compared to previous research findings. The present study showed that the MSGO is highly competitive and demonstrates better efficiency in parameter identification compared to other optimization algorithms. The Individual Absolute Error (IAE) obtained by the MSGO is better than the other errors for most measurement values in the case of single- and double-diode models. Relatedly, the average fitness function obtained by the MSGO algorithm has the fastest convergence rate. Full article

Solar energy has gained prominence because of the increasing global attention received by renewable energies. This shift can be attributed to advancements and innovations in solar cell technology, which include developments of various photovoltaic materials, such as thin film and tandem solar cells, in addition to silicon-based solar cells. The latter is the most widely commercialized type of solar cell because of its exceptional durability, long-term stability, and high photoconversion efficiency; consequently, the demand for Si solar cells has been consistently increasing. PV modules are designed for an operation lifespan of 25–30 years, which has led to a gradual increase in the number of end-of-life PV modules. The appropriate management of both end-of-life and prematurely failed PV modules is critical for the recovery and separation of valuable and hazardous materials. Effective methods for end-of-life PV waste management are necessary to minimize their environmental impact and facilitate transition to a more sustainable and circular economy. This paper offers a comprehensive overview of the separation processes for silicon PV modules and summarizes the attempts to design easily recyclable modules for sustainable solar module development. Based on the studies summarized in this paper, suggestions are provided for future research. Full article

Over the past decade, there has been significant and rapid developments in organic-inorganic hybrid perovskite solar cells (PVSCs). Despite the fact that the power conversion efficiency (PCE) of PVSCs has increased from 3.8% to 25.8%, approaching that of commercial single crystalline Si solar cells, the market is still dominated by Si-based photovoltaic (PV) technology. This can be attributed to the challenges associated with upscaling PVSCs, improving device stability, and reducing the toxicity of PVSCs, which are hurdles in commercializing perovskite PV technologies. In particular, the toxicity due to lead leakage of PVSCs makes it difficult for them to enter the market. Hence, in this article, the structure and working principle of PVSCs are first summarized. Then, the toxicity of PVSCs is discussed, including the impacts of organic solvents and perovskite precursor materials on the health and environment. In this section, examples of advanced strategies for reducing the toxicity of PVSCs are also provided. Finally, challenges and a perspective for developing nontoxic PVSCs are given. Full article

Perovskite-based solar cells are a promising photovoltaic technology capable of offering higher conversion efficiency at low costs compared with the standard of the market. They can be produced via a thin film technology that allows for considerable environmental sustainability, thus representing an efficient, sustainable, flexible, and light solution. Tandem solar cells represent the next step in the evolution of photovoltaics (PV). They promise higher power conversion efficiency (PCE) than those currently dominating the market. The tandem solar cell design overcomes the limitations of single junction solar cells by reducing the thermal losses as well as the manufacturing costs. Perovskite has been employed as a partner in different kinds of tandem solar cells, such as the Si and CIGS (copper indium gallium selenide) based cells that, in their tandem configuration with perovskite, can convert light more efficiently than standalone sub-cells. This brief review presents the main engineering and scientific challenges in the field. The state-of-the-art three main perovskite tandem technologies, namely perovskite/silicon, perovskite/CIGS, and perovskite/perovskite tandem solar cells, will be discussed, providing a side-by-side comparison of theoretical and experimental efficiencies of multijunction solar cells. Full article

PV technology offers a sustainable solution to the increased energy demand especially based on mono- and polycrystalline silicon solar cells. The most recent years have allowed the successful development of perovskite and tandem heterojunction Si-based solar cells with energy conversion efficiency over 28%. The metal oxide heterojunction tandem solar cells have a great potential application in the future photovoltaic field. Cu₂O (band gap of 2.07 eV) and ZnO (band gap of 3.3 eV) are very good materials for solar cells and their features completely justify the high interest for the research of tandem heterojunction based on them. This review article analyzes high-efficiency silicon-based tandem heterojunction solar cells (HTSCs) with metal oxides. It is structured on six chapters dedicated to four main issues: (1) fabrication techniques and device architecture; (2) characterization of Cu₂O and ZnO layers; (3) numerical modelling of Cu₂O/ZnO HTSC; (4) stability and reliability approach. The device architecture establishes that the HTSC is constituted from two sub-cells: ZnO/Cu₂O and c-Si. The four terminal tandem solar cells contribute to the increased current density and conversion efficiency. Cu₂O and ZnO materials are defined as promising candidates for high-efficiency solar devices due to the morphological, structural, and optical characterization emphasized. Based on multiscale modelling of PV technology, the electrical and optical numerical modelling of the two sub-cells of HTSC are presented. At the same time, the thermal stability and reliability approach are essential and needed for an optimum operation of HTSC, concerning the cell lifetime and degradation degree. Further progress on flexible HTSC could determine that such advanced solar devices would become commercially sustainable in the near future. Full article