Panel Recycling Research Articles

The roles of governments for polycentricity’s vulnerabilities: an analysis of South Korea’s PV panel recycling policies

ABSTRACT Polycentricity can be beneficial for analyzing the structures and interactions of multiple decision-makers and for achieving efficient outcomes. In contrast, polycentric governance may not function properly under specific conditions such as external shocks and inadequate institutions. Here, governments can play a significant role in overcoming the vulnerability of polycentric systems. This study uses a case of photovoltaic panel recycling and comprehensively understands the roles of governments in polycentric settings. Polycentricity explains that photovoltaic panels can be efficiently installed and operated through the voluntary transactions of multiple decision-makers. However, the polycentric vulnerabilities can emerge during the recycling stage of solar panel wastes due to shifts in socio-economic factors and limited regulatory capacities. This study suggests that redesigning policy package can empower governments to address the weaknesses of polycentric governance. It highlights the potential application of polycentric governance to energy and environmental management, and emphasizes the significance of governmental intervention for efficient governance.

CFD-DEM study of thermal behaviours of chip-like particles flow in a fluidized bed

Chip-like particles are increasingly practised in various thermal applications, yet the unique heat transfer characteristics are not well understood. In this work, a recently developed super-quadric computational fluid dynamics-discrete element method (CFD-DEM) is extended to couple with heat transfer sub-models to study the cooling behaviours of chip-like particles in a three-dimensional (3D) cylindrical fluidized bed. The effect of aspect ratio (AR) on the flow and thermal behaviours of chip-like particles are studied at the particle scale. The results show that the chip-like particles with an AR of 6 show the steepest temperature decrease and thus the fastest cooling process under the given conditions. The unimodal distributions of particle temperature for the small ARs (i.e., 2 and 4) but bimodal distributions for the large AR (i.e., 6) are captured. Further, a large convective heat flux appears in the dilute phase due to vigorous slip velocity and temperature difference while a small convective heat flux occurs in the dense phase where the chip-like particles tend to be in a close-packing status. Finally, the underlying mechanism is explored: the chip-like particles with larger ARs show better heat transfer performance because the AR enhances gas-solid relative movement intensity and the convective heat transfer flux, and the convective heat transfer dominates the whole particle cooling process. The fundamental study sheds light on the design and optimization of fluidized beds of chip-like particles including solar panel recycling and wood chip gasification.

Technological Advancement in Solar Photovoltaic Recycling: A Review

This review examines the technological surveillance of photovoltaic panel recycling through a bibliometric study of articles and patents. The analysis considered the number of articles and patents published per year, per country, and, in the case of patents, per applicant. This analysis revealed that panel recycling is an increasingly prominent research area. However, the number of patents filed annually has varied in recent years, averaging fewer than 200 per year. The state-of-the-art review identified three main types of treatment for photovoltaic panel recycling: mechanical, chemical, and thermal. Among these, mechanical treatment serves as a preliminary stage before the recovery of valuable elements, which is achieved through chemical or thermal processes. The articles reviewed cover a range of processes, including hydrometallurgical and pyrometallurgical methods, and explore various classification processes, solvents, and oxidizing agents. In contrast, patents predominantly focus on pyrometallurgical processes. This analysis is supplemented by a survey of market-ready technologies, many of which include stages such as size reduction or delamination followed by pyrometallurgical processes. Additionally, the review highlights the collection processes implemented by some companies, noting that the volume of panels considered waste is currently insufficient to maintain a continuous and year-round operational process. This study identifies key challenges such as (i) reducing solar panel size due to the EVA polymer complicating conventional machinery use, (ii) high process costs from the need for high temperatures and costly additives, (iii) the environmental impact of thermal treatments with high energy consumption and air pollution, and (iv) the necessity for environmentally friendly solvents in hydrometallurgical treatments to reduce contamination during recycling. Future directions include developing specific machinery for panel size reduction, either creating or modifying a polymer to replace EVA for easier treatment, adopting hydrometallurgical treatments with green solvents proven effective in recycling minerals and electronic waste, and addressing the lack of detailed information on industrial processes to make more precise recommendations.

The Importance of Photovoltaic Solar Panel Recycling in Romania: Aligning with the Green Deal and Fit for 55 Strategies

Abstract Romania’s flourishing solar energy sector necessitates responsible management of photovoltaic (PV) panel waste. The research examines at the current level of PV panel recycling and anticipates future production of waste. By examining data on solar production capacity and panel characteristics, the study forecasts a significant rise in PV waste. Supportive legislation and rising environmental consciousness have contributed to increased PV installations, but regulating the waste produced is essential. The analysis predicts a jump in trash volume, reaching at least 32,892 tons by 2033, a stunning 2336% increase over 2024–2032. This represents an exceptional chance for Romania to become a European leader in PV panel recycling. Romania could establish an innovative industry, acquire recycled materials for new panels, and encourage a circular solar energy economy if it optimizes its waste management. Together with EU policies to promote the use of recycled materials in the production process of new panels, a national PV waste management strategy needs to be developed, with collaboration between government, industry and environmental organizations. This paper provides significant insights for participants in Romania’s solar energy market. By identifying the challenges as well as opportunities relating to PV waste management, interested parties could collaborate proactively to build an economically viable future for solar energy in Romania.

Design and optimisation of rotary vibrating screening process in silicon photovoltaic panel recycling: A particle-scale model study

The efficient separation of crushed solar panel particles is a critical step in photovoltaics (PV) recycling. In this paper, a DEM-based computer model is used to investigate the separation of crushed solar panel particles in a variety of shapes (including rod-like glass particles and chip-like solar cell particles and small broken residue) at the particle scale in a lab-scale rotary vibrating screen. The screening process of individual particles, including looseness, stratification, collision and penetration, can be well captured by the DEM simulations. Then the effects of several key vibration parameters on screening efficiency are studied, including circular displacements and oscillatory amplitude and frequency, and their underlying mechanism is explored at the particle scale. The simulation results show that with the increase of circular displacements from 1 to 3 mm, the screening efficiency increases from 89.5% to 91.8%. With the rise of oscillatory amplitude from 0.1° to 0.6°, the screening efficiency decreases significantly from 92.0% to 87.3%. With the increase of oscillatory frequency from 10 Hz to 25 Hz, the screening efficiency decreases slightly from 92.1% to 91.2%. The optimal screening condition is identified, i.e., >3 mm circular displacement, <0.1° oscillatory amplitude, and < 10 Hz oscillatory frequency, significantly enhancing screening efficiency. This study is helpful for rotary vibrating screen device scale-up and process optimisation in the PV recycling industry.

Assessing the environmental health and safety risks of solar energy production

Solar energy production has gained significant traction as a promising alternative to fossil fuels, yet its widespread adoption raises questions regarding its environmental health and safety (EHS) risks. This review presents an overview of the current state of research in assessing these risks associated with solar energy production. Firstly, it examines the environmental impacts of solar energy, including the life cycle assessment of photovoltaic (PV) panels and solar thermal systems. Key considerations include the energy and resources required for manufacturing, transportation, installation, operation, and end-of-life disposal or recycling of solar panels. Furthermore, the potential for land use change, habitat disruption, and biodiversity loss due to large-scale solar installations is addressed. Secondly, the review discusses the safety risks associated with solar energy production, focusing on occupational health and safety hazards for workers involved in manufacturing, installation, maintenance, and decommissioning of solar energy systems. It examines exposure to hazardous materials such as lead, cadmium, and silicon during the manufacturing process, as well as the risks of falls, electrical hazards, and other workplace accidents during installation and maintenance activities. Moreover, the review highlights emerging technologies and best practices aimed at mitigating EHS risks in solar energy production. These include advancements in PV panel recycling technologies, improvements in manufacturing processes to reduce environmental impacts, and enhanced safety protocols and training for workers in the solar energy industry. While solar energy offers numerous environmental and economic benefits as a renewable energy source, it is essential to comprehensively assess and manage its EHS risks throughout the life cycle of solar energy systems. This review underscores the importance of ongoing research, innovation, and regulatory oversight to ensure the sustainable and safe deployment of solar energy technologies in the transition towards a low-carbon future.

Policy design of government subsidy for end-of-life solar panel recycling

Solar photovoltaic systems can reduce carbon emissions by harnessing green energy from the sunlight, however, tremendous end-of-life solar panels may pose a threat to the local environment in the coming decades. What's worse, fewer regulations have been mandated to deal with the disposal of solar waste. To address this issue, this paper investigates a game-based, government-subsidized solar recycling model, and extends the model to a dynamic system. By analyzing the equilibrium outcomes, optimal decisions are revealed for all stakeholders. More importantly, we find regulatory subsidies can benefit all members of the solar recycling chain. Furthermore, when confronted with low-quality solar panels with a high degradation rate, we suggest that the government announces a low R&D subsidy rate. Even so, the level of the manufacturer's R&D efforts is still high, which leads to more R&D subsidies provided by the government. Based on an analysis of the dynamic system, it's better to be extremely careful when the government enacts the subsidy policy. Otherwise, the profits of all the chain members may be hurt due to the bifurcation and chaos phenomena.

Solar Sustainability: Redefining Waste Management in Renewable Energy

With the increasing adoption of solar photovoltaic panels, there is a growing concern about their end-of-life management and proper disposal. Improper handling of waste from solar panels can lead to environmental pollution and health hazards. As the demand for solar photovoltaic panels continues to rise, the need for effective end-of-life management and recycling has become increasingly critical. When these panels are not properly disposed of, they can pose serious environmental and health risks. To tackle these issues, it is crucial to have a grasp of the different approaches and technologies accessible for repurposing solar PV panels. It's also vital to take into account the financial and regulatory factors linked to the recycling procedure. In this summary, we will further investigate these matters and examine the present status of solar photovoltaic panel recycling, along with the obstacles and potential for progress that exist.

Solving Solar: How Past Policy Collides With Future Technology

This Comment discusses the importance of developing a solar waste management plan. Specifically, this Comment presents the argument that the United States should not create a large federal regulatory framework that includes expansive subsidies for solar panel recycling, but instead should invest in solar recycling technologies that offer solar recyclers the opportunity to profitably recycle junk panels. Ultimately, the federal government’s role should be limited to one of investment and support as states craft solar waste management systems that work for them.&#x0D; In support of this argument, this Comment explores the history and future of solar panel development, the current state of solar production and recycling, and the magnitude of the threat solar waste presents. Additionally, this Comment discusses how nations outside the United States are addressing the solar waste problem, the advent of new solar recycling technologies, how Congress may adapt the existing Resource Conservation and Recovery Act to include solar panels and encourage recycling of junk panels, the success story of lead-acid battery recycling, and what the solar recycling network of the future may look like.&#x0D; Ultimately, this Comment concludes that given recent advancements in recycling technology, with proper planning, encouragement, and investment from both state and federal governments, the private sector will be incentivized to recycle used solar panels without burdensome government intervention while sustaining a profitable business. Such a result will create a truly clean and renewable source of energy and relieve American taxpayers from bearing the cost of expensive solar recycling subsidy programs.

Circular solar: Evaluating the profitability of a photovoltaic panel recycling plant.

Photovoltaic (PV) panels have a crucial role in coping with the global warming mitigation and the energetic crisis currently affecting the European Community. However, from the circular perspective of end-of-life (EoL) management, there are still big issues to be solved in order to recover materials from this kind of e-wastes. Because of several reasons (e.g. type of embedded materials, illegal shipments, location of manufacturers) EoL businesses do not have the interest in approaching them. This poses a significant environmental concern in terms of their management. This work wants to assess the profitability of a specific PV module recycling plant, by evaluating several market contexts in which multiple scenarios of material price, investment and process costs will be considered. The results for a 3000 tonnes plant show that profitability is not verified in the absence of an avoided landfill cost. Instead, when a value of 200 €/tonnes is applied, the net present value is positive in 35.2% of the scenarios and at 87.6% when a value of 350 €/tonnes is considered. The policy choice of this value requires linking the PV module disposal fee to the circular benefits associated with its recovery.

Concept for Solar Panel Recycling based on High-Temperature Density Separation

The ever-growing application of solar panels for renewable energy has resulted in a significant increase in solar panel waste that is both difficult to recycle and hazardous to the environment. In order to provide a potential solution to this problem, a novel recycling concept employing high-temperature density separation was developed. This was accomplished by firstly completing a thorough literature review on current recycling methods and calculating results using previous experimental and theoretical data. From the results, it was determined that high-temperature density separation has significant potential for making recycling a profitable practice for up to $290/tonne of solar panels. Compared to current recycling methods, high-temperature density separation possesses many benefits such as higher efficiency, potential for energy recovery, and lower environmental impact. This solar panel recycling solution has the potential to greatly improve the sustainability of the solar energy industry while also finding potential applications in other industries that require specialized processing of materials.

Experimental and numerical study of extracting silver from end-of-life c-Si photovoltaic solar cells in rotating systems

The end-of-life (EoL) c-Si photovoltaic (PV) solar cell contains valuable silver, and chemical leaching can extract silver from the cell. However, limited works have been reported on the leaching kinetics and hydrodynamic behaviour of silver leaching process. In this work, an integrated experiment and numerical study are conducted to understand and optimise the silver leaching process in rotating systems. First, the lab-scale physical experiments are conducted to obtain a reaction kinetics model of silver leaching from PV cells. Then, a CFD-DEM model is developed to describe the reacting flow details related to solar cell particles' leaching process including this kinetic model. The model is validated against the lab measurement in terms of flow pattern and leaching performance. Then the CFD-DEM model is applied to a larger rotating system and studies the effects of rotator speed, rotator length, and rotator shape on leaching efficiency. The simulation results indicate that the particles inside the reactor experience mixing, transition, and suspension states with increased rotator length and rotator speed. In the transition state, the particles accumulate near the wall and form a packed bed, leading to the lowest leaching efficiency. In the suspension state, the particles are well fluidized and form a loose, ring-like particle wall. The leaching efficiency has a positive relationship with the fluidization level of the solid phase. The results also show that the leaching efficiency drops when linearly scaling up the reactor size while fixing other operating conditions. This work lays a foundation for process scale-up and optimization of EoL PV panel recycling.

High-yield recycling and recovery of copper, indium, and gallium from waste copper indium gallium selenide thin-film solar panels

A separation process for Cu, In, Ga, and Se (CIGS)-based thin-film solar panels is proposed in this study. Initially, the separation process, by peeling off the panels in a layer-by-layer manner, was achieved by utilizing the different thermal strains of materials inside the CIGS solar panels. Subsequently, the recovery process was performed by annealing the CIGS layers for the removal of Se, and then leaching was performed with nitric acid, followed by the individual extraction of valuable metals. The pH values, concentrations of extractant, stripping agents, organic-aqueous ratios, and reaction time were investigated in detail to optimize the separation conditions for Cu, In, and Ga. First, In was extracted using di-(2-ethylhexyl) phosphoric acid into the organic phase, while Cu and Ga remained in the aqueous phase, by controlling the extraction conditions. After the extraction of In, Ga was extracted using the same extraction agent under different conditions, and nearly pure Cu remained in the residual aqueous solution. Ammonium hydroxide was added to three solutions to form metal hydroxide precipitates. Under the optimal conditions, a recovery rate of >90% could be achieved for In, Ga, and Cu. Furthermore, all as-formed hydroxides were recycled and converted into metal oxides with a purity of >99% by calcination. These findings can provide a pathway for the effective recycling and recovery of Cu, In, and Ga from waste CIGS thin-film solar panels. • A facile and practical method to separate and recover valuable metals respectively from the real commercial thin-film solar panel was demonstrated. • A novel and low-cost physical separation process was induced to peer off the solar panel layer by layer via the extremely low-temperature liquid nitrogen treatment. • An extraction and stripping process was designed to separate Cu, In, and Ga from a complicated multi-element system individually. • Highly pure valuable metal oxides were recovered as the final products, establishing a possible curcular economy model for waste solar panel recycling and recovery.

Biomimetic lignin-protein adhesive with dynamic covalent/hydrogen hybrid networks enables high bonding performance and wood-based panel recycling

Exploring the reusability of wood-based panels is imperative in the wood industry for sustainable development and carbon balance. Non-reusable adhesives make wood-based panel recycling difficult. In this study, inspired by the adhesion and de-adhesion behavior of snail slime, we built dynamic covalent/hydrogen hybrid networks into adhesive system for achieving both high bonding performance and reusability. Specifically, the softwood lignin was purified and pretreated by ultrasonication to form a catechol structure (UAL) and then combined with soybean protein to develop a 100 % bio-based wood adhesive. The catechol structure of UAL formed dynamic covalent bonds (CN) with the amino groups of the protein to improve the water resistance and formed multiple hydrogen bonds as a sacrificial network to improve the toughness of the adhesive. Thus, the wet shear strength of plywood bonded by the resultant adhesive improved by 101.4 % to 1.37 MPa. The adhesive also exhibited flame retardancy (LOI = 37.7 %), mildew resistance (60 h), and antibacterial performance (inhibition zone = 8 mm). Notably, owing to the rearrangement of dynamic covalent/hydrogen hybrid networks and the thermoplastic property of UAL, the resultant adhesive was reusable (3 cycles) and degradable (2 months), which provides a potential method for the reuse of wood-based panels.

Particle-scale modelling of the pyrolysis of end-of-life solar panel particles in fluidized bed reactors

The end-of-life solar panels can be disassembled through pyrolysis by removing the binder - ethylene vinyl acetate (EVA) for panel recycling, yet its research is still in its early stages. In this study, a reactive discrete element method - computational fluid dynamics (rDEM-CFD) model is developed to study the physical-thermal characteristics of dense gas-solid reacting flow related to the solar panel particles’ pyrolysis in two typical chemical reactors - fixed bed (FB) and bubbling fluidized bed (BFB) reactors. The simulation results show that the overall EVA removal degree in the BFB is higher than that in the FB. Then the two key parameters are studied including wall temperature and superficial gas velocity in the BFB. The results show that the EVA removal degrees are improved considerably, from 91.03%, 94.89%, to 99.99%, as the wall temperature increases from 723 K, 773 K, to 823 K. In contrast, the EVA removal degrees at the superficial gas velocity of 1.25 m/s, 1.5 m/s, and 1.75 m/s are similar, i.e., 94.67%, 94.89%, and 95.45%, respectively. The underlying mechanism is explored: the BFB shows better heat and mass transfer performance than the FB, such as more uniform temperature distribution, higher Re and Nu numbers, and larger heat transfer fluxes; on the other hand, increasing wall temperature decreases the Re and Nu numbers while elevating superficial gas velocity enlarges the Re and Nu numbers in the BFB. The study is useful for pyrolyzer design and optimization for efficient solar panel recycling.

Life Cycle Assessment of Disposed and Recycled End-of-Life Photovoltaic Panels in Australia

This study presents a life cycle assessment (LCA) of end-of-life (EoL) photovoltaic (PV) systems in Australia. Three different EoL scenarios are considered for 1 kWh of electricity generation across a 30-year PV system lifespan: (i) disposal to landfill, (ii) recycling by laminated glass recycling facility (LGRF), and (iii) recycling by full recovery of EoL photovoltaics (FRELP). It is found that recycling technologies reduce the overall impact score of the cradle-to-grave PV systems from 0.00706 to 0.00657 (for LGRF) and 0.00523 (for FRELP), as measured using the LCA ReCiPe endpoint single score. The CO2 emissions to air decrease slightly from 0.059 kg CO2 per kWh (landfill) to 0.054 kg CO2 per kWh (for LGRF) and 0.046 kg CO2 per kWh (for FRELP). Increasing the PV system lifespan from 30 years to 50 and 100 years (a hypothetical scenario) improves the ReCiPe endpoint single-score impact from 0.00706 to 0.00424 and 0.00212, respectively, with corresponding CO2 emissions reductions from 0.059 kg CO2 per kWh to 0.035 and 0.018 kg CO2 per kWh, respectively. These results show that employing recycling slightly reduces the environmental impact of the EoL PV systems. It is, however, noted that recycling scenarios do not consider the recycling plant construction step due to a lack of data on these emerging PV panel recycling plants. Accounting for the latter will increase the environmental impact of the recycling scenarios, possibly defeating the purpose of recycling. Increasing the lifespan of the PV systems increases the longevity of the use of panel materials and is therefore favorable towards reducing environmental impacts. Our findings strongly suggest that PV recycling steps and technologies be carefully considered before implementation. More significantly, it is imperative to consider the circular design step up front, where PV systems are designed via circular economy principles such as utility and longevity and are rolled out through circular business models.

Selective grinding of glass to remove resin for silicon-based photovoltaic panel recycling

Secondary grinding was investigated as a mean of liberating glass from locked particles of glass and resin obtained by the primary shredding from the silicon-based PV panels. Many previous studies on separating glass from resin have focused on chemical processes. However, a simple physical process—using an eccentric stirring mill to selectively grind the glass, separating the glass from the resin, and concentrating the glass into a narrower particle size group—resulted in successful liberation. Grinding rate analysis using the population balance model quantitatively confirmed that glass particles were more easily ground than resin particles and that locked particles were more easily ground than free particles. This is because the high specific gravity of the glass particles and the greater adhesiveness of the locked particles cause them to be located near the stirring blade of the mill. The selectivity of grinding became more significant and the grinding time shorter as the rotation speed increased. At the optimal grinding speed of 2500 rpm, 97% of the glass was concentrated into particles under 5.6 mm in size in 5 min. The resulting glass particles had a carbon content of 1% or less, which makes them suitable for the manufacture of glass fiber.

Economic analysis of Solar PV panel recycling project

Economic analysis of Solar PV panel recycling project

Environmental Impact Assessment of crystalline solar photovoltaic panels’ End-of-Life phase: Open and Closed-Loop Material Flow scenarios

The full life cycle of today's crystalline photovoltaic (PV) panel is dominated by a linear, open material flow paradigm. The Cradle-to-Cradle philosophy (C2C) applied in a Closed-Loop-Material-Cycle (CLMC) scenario seems promising to move towards a Circular Economy (CE). Environmental impacts associated with the End-of-life (EoL) phase of PV panels, particularly a CLMC scenario, have not yet been evaluated. To this end, this article uses the Life Cycle Assessment methodology to compare a linear Open-Loop-Material-System (OLMS) scenario with a novel CLMC system. Based on our results, the environmental impacts of a PV CLMC scenario are then compared with a Cadmium telluride (CdTe) panel CLMC scenario.In terms of environmental impacts, the recovery of PV materials in a CLMC scenario results in substantial improvements over an OLMS scenario. Closing the material flow has reduced the Climate Change impact factor (kg CO2 eq) by 74%, compared with the OLMS scenario. However, EoL PV recycling technology still remains behind in environmental and energy intensity terms when compared to the EoL CdTe panel recycling technology within a CLMC scenario. Furthermore, during the recycling processes, our results showed that the highest specific energy uptake was 3264 TJ for PV, while for CdTe it was 2748 TJ. On the other hand, the use of toxic chemicals to recover Si and Cd are shown to significantly contribute to the environmental impacts of both EoL PV and CdTe CLMC scenarios.Results show that the CLMC based on C2C principles has a favorable impact by reducing the environmental burden at the EoL. Nevertheless, it is imperative to reduce environmental burdens from the current thermochemical processes used to recycle silicon and to start considering the key role of C2C principles for PV panel design and recycling processes, aiming at the introduction of a CLMC system based on new standards and consistent regulations in order to reduce the environmental impacts of current PV panels, if a sustainable PV technology is desired.

End-of-Life Liquid Crystal Display Recovery: Toward a Zero-Waste Approach

End-of-life liquid crystal displays (LCD) represent a possible source of secondary raw materials, mainly glass and an optoelectronic film composed of indium (90%) and tin (10%) oxides. A strong interest for indium, classified as critical raw material, pushed research towards the development of high-efficiency recycling processes. Nevertheless, a deepened study of the technological innovation highlighted that only a small number of treatments included use of whole waste. Furthermore, these processes often need high temperatures, long times, and raw materials that have a significant environmental impact. In this context, this article shows an approach developed in accordance with the “zero waste” principles for whole, end-of-life LCD panel recycling. This process includes preliminary grinding, followed by cross-current acid leaching and indium recovery by zinc cementation, with efficiencies greater than 90%. A recirculation system further increases sustainability of the process. To enhance all waste fractions, glass cullets from leaching are used for concrete production, avoiding their disposal in landfill sites. Considering the achieved efficiencies, combined the simple design suitable for real-scale application (as confirmed by the related patent pending), this process represents an excellent example of implementing circular economy pillars.