Photovoltaic Waste Research Articles

Understanding the possibility of material release from end-of-life solar modules: A study based on literature review and survey analysis

Abstract The present study addresses the aspect of upcoming stream of photovoltaic waste by investigating the possibility of material release from end-of-life solar modules using an integrated approach of literature review and stakeholders survey. It involved (i) identification of failure events responsible for degradation of photovoltaic modules as per literature review, (ii) evaluation of identified events by a survey of stakeholders of photovoltaic industry and (iii) investigation of solar industry’s stakeholders’ perceptions on events responsible for generation of end-of-life modules, and present management and recycling practices, (iv) fault tree analysis for estimating probability of material release, and (v) calculation of risk priority number for finding severity of failure events responsible for dumping and material leaching from solar modules. An assessment of previous studies on degradation of solar modules indicates that environmental factors, like high UV irradiation, humidity, temperature play significant roles in module degradation. As per survey, more than 90% of manufacturers were involved in crystalline-silicon photovoltaic business. Only 20% manufacturers replied when asked on the aspect of end-of-life modules, showing that the photovoltaic waste is comparatively a new subject and not enough discussion have been devoted to it. Lack of recycling infrastructure, incentives, and environmental awareness significantly influence recycling and recuse practices. On the basis of worst-case scenario, the maximum probability of the material release from dumped solar panels was estimated to be 0.053. As per manufacturer’s opinion, the most critical factors resulting in modules failure are glass breakage and encapsulant degradation. Among various events from manufacturing to end-of-life stage, the module breakage during operation event have highest probability value (i.e., 0.313). Risk priority number analysis suggests that generation of end-of-life photovoltaic and environmental damage resulting to metal leaching as the most significant events. Damage during manufacturing and installation were identified to be the least significant events resulting in degradation. At present, 76% producers do not recycle or reuse photovoltaic waste material, preferably sell them to informal waste recyclers or rag pickers. Findings from the present study highlight the urgency to develop a suitable system for collection and management of end-of-life modules.

Within the global circular economy: A special case of Turkey towards energy transition.

Circular energy transformation of Turkey is essential to strengthen the national energy security. Turkey will benefit from moving towards a circular economy.Circular economy (CE) has gained much attention due to global warming and climate change which are the most serious issues faced in the world. The United Nations has been struggling with the issues regarding sustainable development by releasing some programs and legislations, which are mostly supported by the EU. The EU's CE including both economy and energy within the scope of low-carbon world is binding for Turkey's energy transition. Among renewables, solar energy preserved the leading capacity expansion with an increase of 98 GW in 2019 in the world. Solar photovoltaic (PV) has become a mainstream energy source among renewables. Since the PV installation has been growing all around the world, several countries especially China, Germany, and the UK pay special attention to a sustainable PV waste management concept. We present the special case of Turkey within the global CE along with the current status of renewable energy in the global energy transformation. Turkey's energy outlook and the EU's targets are reviewed, and the significant role of solar energy in the CE transition process of Turkey has been revealed. We suggested adding a vision of “More Circular” to her new energy policy “More Domestic, More Renewable.”

A Low-Cost Preparation of Si@C Composite Anode from Si Photovoltaic Waste

A Low-Cost Preparation of Si@C Composite Anode from Si Photovoltaic Waste

Preparation of reactive sintering Si3N4-Si2N2O composites ceramics with diamond-wire saw powder waste as raw material

In this paper, the reactive sintering Si3N4-Si2N2O composites ceramics were fabricated from the diamond-wire saw powder through the reaction-sintering nitridation method. The effects of sintering temperatures, holding time and oxygen contents on the Si3N4-Si2N2O composites formation were investigated in detail. The results revealed that the phases of final products consisted of α/β-Si3N4 and Si2N2O, and the proportion of three phases could be influenced by sintering temperatures and oxygen contents. In addition, rod-like particles and clastic granules were observed in final specimens, and rod-like particles mainly formed in low sintering temperatures and low oxygen contents, which could be attributed to the vapor-vapor-solid (VVS) growth mechanism. Furthermore, a lot of rod-like particles were distributed in cracks among the Si3N4-Si2N2O composites matrixes, which formed the bridge structures and enhanced the mechanical properties. The specimen obtained at 1500 ℃ with 5 wt.% SiO2 in raw materials had the highest compression strength of 150.6 MPa and the highest flexural strength of 46.1 MPa. Comparing with other typical composites, the Si3N4-Si2N2O composites in this work showed the desirable mechanical properties. Thus, this study provided an environment-friendly approach to recycle photovoltaic waste and reduce the cost of the reactive sintering Si3N4-Si2N2O composites ceramics.

Application of multi-stage vacuum distillation for secondary resource recovery: potential recovery method of cadmium telluride photovoltaic waste

With the widespread use of cadmium telluride solar cells, environmental protection, and effective recycling approaches for solar cell component waste have become topics of concern. As an emerging metal smelting technology, vacuum metallurgy technology has broad application prospects in primary metal refining and the recycling of secondary non-ferrous scraps. Thus, this study proposes a new method for the separation and recovery of rare metals from cadmium telluride waste through sulfur smelting and vacuum distillation. In this process, sulfur is smelted with cadmium telluride to produce tellurium with a high vapor pressure. The tellurium was then separated and purified by multi-stage vacuum distillation. The results show that the tellurium purity can reach up to 99.97% and the tellurium recovery rate was above 99%. The cadmium and sulfur contents in the tellurium were 0.0061% and 0.0194%, respectively. Moreover, the cadmium sulfide produced during the smelting process can be enriched by vacuum distillation, resulting in 99.6% purity. This technology strongly aligns with the “reduce, reuse, and recycle” principle for solid waste, and provides a basis for the sustainable development of the photovoltaic industry.

A compatible standard policy measure to tackle solar photovoltaic waste in Indian scenario

Expeditious evolution of solar photovoltaic industry has triggered transformation in energy sector across the world. After the concluded durability of the PV panels amount of junk originates. This junk is directed into the category of solid waste. With the increasing solar power plant installations in India the amount of waste to be accumulated in the nearby years to come will be a matter of grave concern. Hasty action should be taken by the Indian policy makers and other non-governmental agencies to process the solar photovoltaic recycling policies at commercial level in an economically sustainable manner. This paper inspects the prospective requisite of PV reprocessing legislation by investigating the current reprocessing arrangements of the commercialized first and second generation solar PV materials. Emphasis is also laid on the hazardous effects of the waste on human body. Quantity of reclaimed material is considered and its economic importance is analysed. Architectural liability is put at the utmost front for curbing out the havoc to be created by piling up of the junk photovoltaic materials through economically feasible policy framework. Through this article effective solar PV reclaiming policy framework is proposed for the Indian government which will foster new socio-economic, environmental and employment opportunities.

Promoting a circular economy in the solar photovoltaic industry using life cycle symbiosis

As society works to reduce its reliance on fossil fuels, the demand for renewable energy has grown rapidly in recent years. Photovoltaic (PV) solar power is one such source of renewable energy and has seen significant growth over the past several decades. While End of Life (EoL) PV volumes remain relatively small at this time, the number of EoL PVs is estimated to grow dramatically in the near future. This raises concerns about the management of EoL PVs. Effective EoL management methods need to be aggressively developed and implemented in order to prevent large volumes of hazardous wastes from being disposed in landfills. At the same time, PV waste can also be viewed as a potential source of valuable materials. The development of effective processing technologies to isolate these materials will help divert waste away from landfills while reducing dependence on virgin resources and enhancing economic sustainability. This paper proposes the circularization of the PV industry by applying the notion of Life Cycle Symbiosis (LCS), an extension of Industrial Symbiosis (IS). By identifying waste streams that may have value as potential raw material/feedstock, through the development of collaborative business/economic interactions among a diverse set of organizations, we have applied LCS in the context of EoL PVs. The avoided global warming potential (GWP) and ecotoxicity impacts 2750 kg CO2 eq and 32,000 CTUe per metric ton of EoL PVs respectively, while the water savings and electricity savings were 37,735.65 m3 and 3615.11 MJ per metric ton of EoL PVs.

Update of the Projection of the Photovoltaic Waste in Spain until 2050

Update of the Projection of the Photovoltaic Waste in Spain until 2050

Experimental Study on Fluorine Release from Photovoltaic Backsheet Materials Containing PVF and PVDF during Pyrolysis and Incineration in a Technical Lab-Scale Reactor at Various Temperatures.

With a sharp increase in photovoltaic (PV) installations across the world, PV waste is now a relatively new addition to the e-waste category. From 45,000 tonnes in 2016, the PV waste stream is rapidly increasing and is projected to reach 60 million tonnes by 2050. Backsheets are composite structures made from several material layers of polymer, adhesive, and primer. Widely used PV backsheets can be classified into three core types: (a) KPK (Kynar®/polyethylene terephthalate (PET)/Kynar®), (b) TPT (Tedlar®/PET/Tedlar®), and (c) PPE (PET/PET/ethylvinylacetate). Kynar® and Tedlar® are based on polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF), respectively. PPE backsheets are fluorine-free composites made primarily from PET. With increasing focus on the end-of-life (EoL) handling of PV waste, the handling of fluoropolymers, which is largely unexplored, requires closer examination to avoid environmental damage. The aim of this study was to obtain information on the fluorine released from PV backsheet materials into the gas phase during combustion and pyrolysis as EoL pathways. Therefore, several experimental trials were conducted to measure fluorine transfer into the gas phase at 300 °C, 400 °C, 500 °C, and 900 °C (for pyrolysis) and at 750 °C, 850 °C, and 950 °C (for incineration).

Innovative device for mechanical treatment of End of Life photovoltaic panels: Technical and environmental analysis

The paper contributes at filling the lack of knowledge on Photovoltaic (PV) panels recycling through the analysis of a mobile mechanical treatment plant developed within the context of a European project. The process, the machinery installed in the system and their main functionalities are described. The data are used to perform a Life Cycle Assessment (LCA) focused on the End-of-Life (EoL) process, assuming as Functional Unit (FU) the treatment of a 20 kg PV panel. The system boundaries include construction and operation of the device as well as recycling and incineration of different material fractions performed outside the plant. The inventory is mainly based on primary data coming from a collection carried out directly on the recycling device. The results show that impacts are concentrated on operation stage mainly due to energy consumption involved in milling and separation activities. The analysis of different operation steps reveals that pre-treatment gives the highest contribution, followed by glass and silicon separation with the lowest quota attributable to copper and polymeric fraction separation. Considering also recycling and incineration processes of EoL waste, the environmental credits due to the avoided production of virgin raw materials counterbalance the burdens of construction and operation for most of impact categories. The comparison of results with existing LCAs of fixed recycling installations stresses that the use of a mobile system involves considerable environmental benefits thanks to the reduction of transports needed to move EoL PV waste to the recycling facility site.

Solar photovoltaic tree and its end-of-life management using thermal and chemical treatments for material recovery

Solar photovoltaic trees (SPVT's) are chosen as an alternative option for electricity generation due to numerous benefits (especially in land utilization, urban infrastructure, and landscaping). Currently, SPVT's are available in many designs, and one among them is the novel phyllotaxy pattern. Technically, SPVT's seem to be more reliable and cost-effective. The expected average lifetime of the photovoltaic (PV) modules used in SPVT's is around 25 years. Once, the lifetime is over, these SPVT's must undergo a waste management process, and the scope for recycling is very high. Even though the scope for PV waste recycling is very high, many recyclers face the problems especially in estimating material recovery potential. In this paper, thermal and chemical treatments based end-of-life (EOL) method is used to estimate the material recovery potential from the phyllotaxy pattern-based SPVT. Initial estimations on the total embodied materials of the SPVT system is evaluated based on the components material fraction. Next, under the applied EOL management method, material recovery potential is estimated as per the material (aluminum, copper, glass, silver, and steel). Lastly, a few limitations with this EOL method are highlighted, and presented results aim to serve as useful data for the recyclers to have decisions.

Controllable fabrication of tendril-inspired hierarchical hybrid membrane for efficient recovering tellurium from photovoltaic waste

Fabrication of membrane-based adsorbent with outstanding functions for efficient recovering tellurium from photovoltaic waste has been intriguing but is still challenging. Inspired by the winding of tendrils, herein, a membrane-based adsorbent for tellurium separation has been fabricated via winding calcined micron-sized Mg–Al layer double hydroxides (LDHs) fibers with the acid of ultralong MnO2 nanowires (UL-MnO2-NWs). To obtain the calcined LDHs fibers, Al2O3 fibers was fabricated by template-directed synthesis employing cotton fibers as templates, and then the calcined LDHs fibers were prepared via crystal growth on Al2O3 fibers surface and subsequent calcination treatment. UL-MnO2-NWs were obtained by a hydrophobic route. The immobilized LDHs in the tendril-inspired membrane allow the tellurium to be adsorbed in matrix from the simulate leaching solution of CdTe photovoltaic waste with permeate flux of 34 m3/m2h. It is worth mentioning that the tendril-inspired membrane achieves ultrahigh removal efficiency up to 98.73%. The static soaking tests proved the excellent mechanical stability of the tendril-inspired membrane. More importantly, the tendril-inspired membrane can be regenerated via elution and calcination processes, which match well with the requirements for practical separation applications. Under the cyclic tests, the tendril-inspired membrane still maintains a high level of separation after 5 cycles. As a high-efficient, mechanically stable, and regenerated membrane-based adsorbent, tendrils-inspired membrane has tremendous potential to handle and recycle toxic tellurium containing compounds.

In situ fabrication of dynamic nano zero-valent iron/activated carbon nanotubes membranes for tellurium separation

Recovery of valuable elements from (industrial process) photovoltaic wastes would be beneficial for both economical and sustainability reasons. In this work, nano zero-valent iron/activated carbon nanotubes (NZVI/ACNTs) hybrid membranes were fabricated by using NZVI as dynamic layer and CNTs as substrate for deep tellurium extraction, where the NZVI particles were formed by in situ reduction. Batch experiments were conducted to investigate the adsorption properties of NZVI/ACNTs hybrid membranes under different solution conditions such as pH, temperature, sorbent dosage, and competitive ions. Energy dispersive X-ray and X-ray photoelectron spectroscopy results confirmed good adsorption capacity of tellurium by NZVI/ACNTs through redox reactions. The tellurium adsorption capacities decreased in the presence of competitive ions and as the concentration of NO3− significantly increased, the adsorption quantity dropped from 331.6 to 286.5 mg/g. Extraction of tellurium under weakly acidic conditions had a positive effect and reached a maximum adsorption capacity about 800 mg/g at pH 4.7. Kinetic models and equilibrium isotherms fitted well to the adsorption experimental data indicating that chemical adsorption dominate during the adsorption process of NZVI/ACNTs-Te. As a reusable and high-efficient adsorbent, NZVI/ACNTs membrane has tremendous potential to handle and recycle toxic tellurium containing compounds.

Resource efficient recovery of critical and precious metals from waste silicon PV panel recycling

Although the amount of waste photovoltaic (PV) panels is expected to grow exponentially in the next decades, little research on the resource efficiency of their recycling has been conducted so far. The article analyses the performance of different processes for the recycling of crystalline silicon PV waste, in a life cycle perspective. The life cycle impacts of the recycling are compared, under different scenarios, to the environmental benefits of secondary raw materials recovered. Base-case recycling has a low efficiency and, in some cases, not even in line with legislative targets. Conversely, high-efficient recycling can meet these targets and allows to recover high quality materials (as silicon, glass and silver) that are generally lost in base-case recycling. The benefits due to the recovery of these materials counterbalance the larger impacts of the high-efficiency recycling process. Considering the full life cycle of the panel, the energy produced by the panel grants the most significant environmental benefits. However, benefits due to high-efficient recycling are relevant for some impact categories, especially for the resource depletion indicator. The article also points out that thermal treatments are generally necessary to grant the high efficiency in the recycling. Nevertheless, these treatments have to be carefully assessed since they can be responsible for the emissions of air pollutants (as hydrogen fluoride potentially released from the combustion of halogenated plastics in the panel’s backsheet). The article also identifies and assesses potential modifications to the high-efficiency recycling process, including the delocalisation of some treatments for the optimisation of waste transport and the introduction of pyrolysis in the thermal processing of the waste. Finally, recommendations for product designers, recyclers and policymakers are discussed, in order to improve the resource efficiency of future PV panels.

Photovoltaic waste assessment: Forecasting and screening of emerging waste in Australia

Australia has to meet the challenges of End-of-Life treatment of photovoltaic modules in coming years due to rapid growth of photovoltaic capacity during the last decades. This paper contributes towards the sustainable management of decommissioned solar panels through the estimation of PV waste flow between the years 2031–2047 based on the actual installation of the PV modules from 2001 to 2018, and the provision of a forecasting model applying on four major scenarios to project the waste generated from 2048–2060. Assuming three forecasting schemes, and consistent annual-growth-rate of PV installation for each scenario, the future PV waste was quantified. Considering the PV installation from 2001 to 2018, the cumulative waste is estimated to be 0.8 million tonnes until 2047. The mainstream of the waste is estimated to be glass and aluminium with 541,209 and 116,483 tonnes respectively, followed by 8375 tonnes of copper and 71,329 tonnes of steel. The PV waste includes various valuable substances which, if appropriately recycled, can bring significant economic benefit. With regards to all PV penetration scenarios in the electricity generation market until 2030, Australia is estimated to face around 1–8 million tonnes of decommissioned PV until 2060. The recovery of the EoL PV raw materials can lead to value creation of nearly 1.2 billion dollars. These findings can shed light on the possibility of a circular economy and suggest an active contribution of all parties and a very well-planned coordinated approach prevent the potential environmental impacts and maximize resource efficiency.

Recycling perovskite solar cells through inexpensive quality recovery and reuse of patterned indium tin oxide and substrates from expired devices by single solvent treatment

The predominant expense for the manufacturing cost of new generation photovoltaic devices including perovskite solar cells (PSC) emanate from the use of indium tin oxide (ITO) as transparent electrodes and is due to its limited supply and patterning costs. The PSC devices also struggle with low lifetime, and thus it has a high potential of generating rapid end-of-life (EOL) products resulting in surged photovoltaic wastes. In addition, the PSC devices contain unfavorable toxic elements such as lead and thus any effort to tackle the problem would help the environmental sustainability. In this article, the aforementioned issues were solved by the quality recovery of patterned ITO substrates from old devices through “top-down” approach, which essentially stripped out the unsought component layers present on ITO and subsequently reused for fresh devices. The PSC recycling and ITO recovery was done by treating EOL device with a single non-volatile inexpensive alkaline solvent. The appropriately recovered ITO had shown (optical, surface and electrical) properties close to the reference and was found to be suitable for direct reuse as the best power conversion efficiency (PCE) of recycled PSC varied only 0.85% less than the initial device.

The environmental and economic impacts of photovoltaic waste management in Thailand

Renewable energy technology is being adopted into energy plans worldwide to reduce the mounting CO2 emissions of traditional energy sources. Currently in Thailand, there are approximately 15 million solar panels (2600 MW) which will need to be disposed of in the coming years. The average lifespan of a crystalline silicon panel is between 20 and 30 years, and responsible treatment of these end-of-life panels is necessary to minimize environmental burdens. Thailand’s current plan is to landfill these panels. This study hopes to shed light on the environmental and economic paybacks that could materialize from recycling solar panels. It has been hypothesized that recycling solar panels could result in less environmental burdens than landfilling, but at an added monetary cost. Using LCA methodology and the EcoInvent database, this paper compares the environmental impacts of landfilling end-of-life crystalline silicon panels with those of two different recycling methods. By recycling silicon-based solar panels, valuable metals within the panels can be recovered instead of lost to the landfill. Recycling PV panels is less environmentally burdensome than landfilling when credits are applied to the recycling methods for the avoided production of materials that are recovered from the panels. Using the discounted cash flow method, this paper also compares the three waste management plans financially, as costs will inevitably influence how PV waste is managed in Thailand in the years to come. Neither of the recycling facilities were found to be economically profitable, however the cost to recycle could be as little as $0.03 per kg.

Creating Sustainable Photovoltaics for Smart Cities

Research on solar energy systems and materials has yielded promising opportunities for sustainable energy solutions, which do not only consider environmental issues but also allow aesthetic design possibilities. New requirements regarding the energy efficiency performance of buildings gave the basis for two European projects aiming at sustainable energy solutions, which consider both environmental issues and aesthetic design. All research findings were expected to be in line with the EU’s Waste Electrical and Electronic Equipment (WEEE) directive. FP7 SolarDesign put a focus on novel printing and scribing methods which make possible the manufacturing of flexible monolithically interconnected photovoltaic modules to be integrated into both devices and building envelopes. This technology allows customization of the PV modules’ shape, size and voltage. SolarDesign developed a solar foil with a width of 300mm, basis for curved solar cells with a minimum radius of 10mm. The H2020 project CABRISS contributes to a circular economy that manages the critical situation of recycling a significant volume of photovoltaic waste. The project also contributes to electronics, metallurgy and glass industries. CABRISS comprises the development of: (i) recycling technologies to recover In, Ag and Si, (ii) demonstrating the possibility for the re-usability and recyclability of end-of-life key PV materials. Both projects involved European standardization bodies (CEN/CENELEC, SEMI).

Scalable Engineering of Bulk Porous Si Anodes for High Initial Efficiency and High-Areal-Capacity Lithium-Ion Batteries.

Nano-Si has been long-hampered in its use for practical lithium battery anodes due to its intrinsic high surface area. To improve the Coulombic efficiency and areal mass loading, we extend the starting materials from nano-Si to photovoltaic waste Si powders (∼1.5 μm). Unique morphology design and interfacial engineering are designed to overcome the particle fracture of micrometer Si. First, we develop a Cu-assisted chemical wet-etching method to prepare micrometer-size bulk-porous Si (MBPS), which provides interconnected porous space to accommodate volume expansion. In addition, a monolithic, multicore, interacting MBPS/carbonized polyacrylonitrile (c-PAN) electrode with strong interfacial Si-N-C is designed to improve the interparticle electrical conductivity during volume expansion and shrinkage. Furthermore, intermediate Si nanocrystals are well-maintained during the lithiation of MBPS, which facilitates the reversibility of lithiation-delithiation process. As a result, the MBPS/c-PAN electrodes exhibit a reversible specific capacity of 2126 mAh g-1 with a high initial Coulombic efficiency of 92%. Moreover, even after increasing the capacity loading to 3.4 mAh cm-2, the well-designed electrode shows a capacity retention of 94% in the first 50 cycles at a current density of 0.2 A g-1 with deep lithiation and delithiation processes between 0.005 and 2.5 V.

PV Waste Management at the Crossroads of Circular Economy and Energy Transition: The Case of South Korea

The South Korean government’s renewable energy deployment plan aims to increase the share of electricity generated from renewables to 20% by 2030. To reach this goal, the rate of photovoltaic (PV) installation will accelerate in the coming years. This energy transition creates a new challenge: PV wastes. This study estimates the amount of PV waste generated, the material composition of PV waste, and the amount of recyclable metals in South Korea by 2080 under four different scenarios (combining shape parameters of 5.3759 [regular-loss] and 3.5 [early-loss] with PV module lifespans of 25 and 30 years) using the Weibull distribution function. The annual waste generated will fluctuate over time depending on the scenario, but between 4299 and 5764 thousand tons of PV waste will have been generated by 2080. Under the early-loss/25-year lifespan scenario, annual PV waste generation will increase to exceed 130,000 tons in 2045, then decrease through 2063 before increasing once again. The fluctuation in annual PV waste generation appears stronger under regular-loss scenarios. An appropriate system for the monitoring, collection, and storage of PV waste needs to be arranged even before the volume becomes high enough for recycling to be economically viable. International cooperation could be a way to maintain the PV waste stream at an economically feasible scale. It would also be a good idea if the PV module could be designed in a way that would enable easier recycling or reuse.