Introduction
India is one of the biggest contenders for the production of green electricity in the world, with solar being the frontrunner in the race followed by the wind on number two. (Srinivas, 2021) India’s solar industry is making continuous strides in achieving technical advancements and has successfully surpassed Italy to take fifth place globally for solar power deployment. (MNRE, 2021) However, with an increasing demand for photovoltaics, the problem of solar waste management is foreseeable, necessitating the implementation of proper waste management strategies. This study focuses on developing a proper waste management strategy for the Indian solar industry, considering various technical and economical factors. The study begins with research and identification of annual module waste generation in India for making an assumption on annual recycling targets, followed by a techno-economic analysis of recycling technologies considering various parameters such as energy, cost, and infrastructure development. Finally, the research suggests a viable business model for the recycling industry in India. Furthermore, this study focuses on the research and development of several policies that are necessary for the adaptation and implementation of these strategies and the development of required infrastructure.
Module Waste in India
India’s solar waste generation is predicted to reach 34,600 million tonnes by 2030. (Jasleen Bhatti, 2022) A typical PV module generally consists of materials like silicon, glass, aluminum, and other metals like lead and cadmium telluride. Glass and aluminum make up over 80% of the module and are non-toxic, however, metals like lead and cadmium telluride are environmentally dangerous and must be processed and disposed of properly. (Sangeetha Suresh, 2019)
According to a report “Waste Management in India” published by EU-India Technical cooperation: PV waste is not only produced after the end of a module life but also during the origin, transportation and manufacturing of the module. However, the biggest share of waste produced by a module is after its End Of Life (EOL). But considering the life of solar modules to be 30 years, the report neglects the EOL waste streams, as EOL will become more significant in the early 2040s. Consequently, the study predicts a 10-year projection that takes into account a variety of damaging factors such as transportation damage, installation damage, harsh weather conditions, and technical failures. Table 1 shows the assumed cumulative amount of solar waste created between the years 2021 to 2030 in India, considering above mentioned factors. Manufacturing damages are also ignored in the report because they are minor and can be repaired throughout the manufacturing process. (Cooperation, 2021)
| 2021 | 2022 | 2023 | 2024 | 2025 | 2026 | 2027 | 2028 | 2029 | 2030 | |
| Low | 0.8 | 1.6 | 2.6 | 3.6 | 4.6 | 5.7 | 7.0 | 8.3 | 9.7 | 11.2 |
| Medium | 1.4 | 2.9 | 4.5 | 5.8 | 7.4 | 9.3 | 11.5 | 14.2 | 17.2 | 20.8 |
| High | 1.8 | 6.5 | 11.4 | 16.2 | 20.7 | 24.8 | 28.2 | 31.0 | 33.1 | 34.6 |
From the table above, it can be estimated that India’s annual recycling targets for 2021 will be between 0.8 and 1.8 kilotonnes. Similarly, for the next nine years, the same prediction can be made.
Analysis of Waste Management Technologies
Technology plays an important role in the process of waste management. The recycling industry is transforming dramatically, thanks to newly developed and highly automated systems. This section provides a techno-economic assessment of various solar module recycling technologies and a comparison to determine the most feasible option for solar waste recycling.
The recycling process of solar modules begins with disassembling of solar panels. A typical solar module is largely recyclable, with materials like glass, aluminum, and silicon that can be recycled. After the disassembly of solar panels, the remaining materials undergo the process of delamination. Mechanical, thermal, and chemical procedures have so far been the most prevalent ways for recycling PV modules. (Marina Monteiro Lunardi, 2018)
In the mechanical process, the module is delaminated physically by hammering, shredding, and cutting into pieces of different sizes that can later be sorted manually. In the case of chemical delamination, the glass is separated from the module by submerging (dissolving/immersing) the module in nitric acid for 24 hours or by successfully dissolving EVA in trichloroethylene at 80 °C for 10 days. The rate of chemical delamination can be increased by providing ultrasonic radiation. In the thermal process, the encapsulating layer between the glass and the solar cells is thermally decomposed to separate the module. Under an inert gas environment, the polymeric encapsulation layer, mostly EVA, can be pyrolyzed into acetic acid, propane, ethane, methane, and other combustible oils and gases, or burned off under an oxygen atmosphere. (Rong Deng, 2019) There are many more technologies like mechanical separation by hotwiring cutting, electrothermal heating, and organic solvent dissolution which are currently in the research phase or in the developing phase that can prove to be more efficient and viable options for module delamination in the future. (Marina Monteiro Lunardi, 2018)
After delamination of modules, the module waste undergoes a leaching/etching process which helps in separating metals and silicon. Solar cell electrodes and linked ribbons comprised of Ag, Al, and Cu are recycled by dissolving them in aqueous media. Solar cell powders and ashes that are produced due to mechanical damage during module delamination are treated in nitric acid or aqua regia to separate metallic components and filter silicon residue. Various methods, such as electrolysis and precipitation, can also be used to extract and purify the metal from the leaching solution. (Rong Deng, 2019) . Several new and innovative techniques for extracting and recovering valuable metals from module waste are currently being explored to attain complete wafer recovery. (Youn Kyu Yi, 2014) For further analysis and understanding of the recycling technologies, a comparison has been made in Table 2 and Table 3, considering several factors like energy utilization, process efficiency, advantages,
| Energy Utilisation | Process Efficiency[1] | |
| Mechanical Process | Low | High to Very High (90 -99% materials recovered) |
| Thermal Process | Very High | High (almost 85% Material recovered can be reused) |
| Chemical Process | High | High (almost 95 %) |
[1] Note: The process efficiency varies from company to company, therefore this data may vary and disadvantages.
| Advantages | Disadvantages | |
| Mechanical Process | No chemicals are involved. Low environmental burden.Low energy demand.Easy Availability. | Difficulty in the separation of silicon from smaller glass particles. |
| Thermal Process | Economical feasibility.Complete removal of EVA.Recovery without cell intact. | High cost of chemicals used. High energy requirements.Formation of emission-creating gases. |
| Chemical Process | Easy removal of materials.Efficient process. | Time-consuming process.High costs of solvents involved. |
Economic Analysis
Cost plays a vital role in the development of technology, strategy, and their related infrastructure. Even though the cost-benefit of recycling is dependent on other components of recycling, such as collecting and sorting to separate the Si cells from other ancillaries, recycling of PV modules is required to comply with regulatory requirements in various places across the world. From a corporate and social responsibility standpoint, the industry should handle and recycle its waste in a way that complements the “green energy” PV systems project. (Youn Kyu Yi, 2014)
When making a cost comparison between various technologies, that are used for the process of recycling certain factors should be considered, i.e. their infrastructure requirements, material or chemical costs, and energy utilization costs. For example, if a cost comparison is made between thermal, mechanical, and chemical processes variability between the process costs can be observed. The thermal process is economically feasible but on the other hand, they have a high energy demand, which adds a certain amount of costs to the process. Similarly, if the mechanical process is considered, which has low energy demand but in addition, the silver recovery from the process is less due to the crushed material. (Dávid Strachala, 2017) The chemical process is alternatively a process with a very high metal recovery rate but it incurs heavy costs of materials and chemicals used during the process.
For the implementation of a better strategy and making the recycling process economically feasible, providing subsidies to the solar recycling industry can prove to be a viable option. According to the researchers’ calculations, 40% of all solar panels may be reused and recycled with subsidies of $18 per panel for a period of 12 years. By 2032, a lucrative and sustainable solar panel recycling industry might emerge at that pricing. Considering the recycling cost of a module to be 28$ and 18$ subsidy/ module reduces the module recycling cost to 10$, it would take 12 years to obtain a 20% solar panel recycling rate and profit. This is six years ahead of the $10 per module subsidy, which reduces recycling costs to $18 per module and takes 18 years to achieve the same 20% rate. (WEAVER, 2021)
Solar Module Recycling Business in India
The solar panel recycling sector encompasses a wide range of activities, from solar panel decommissioning to solar panel collection, sorting, and recycling. The module recycling business is currently a niche sector due to the small number of companies that participate in solar panel recycling. (Bridge, 2021) With no policy for solar module recycling, (Jasleen Bhatti, 2022) India lacks behind in the recycling business considering most of the solar waste gets into the landfills. Only the EU has enacted special waste standards for solar panels, which demand an 80% recovery and 75% recycling rate of solar panels waste. On the other hand, general waste rules in the United States of America and Japan may include solar panel testing for hazardous materials content, as well as the prescription or prohibition of certain transportation, treatment, recycling, and disposal paths. Although it has not regulated solar panel waste recycling, Japan is the only Asian nation that has taken steps to promote solar panel recycling by financing recycling equipment. (Bridge, 2021)
The EU WEEE (Waste from Electrical and Electronic Equipment) directive establishes specific collection, recovery, and recycling objectives for EU member nations. As a result, all member nations must meet a minimum collection objective of 4 kg per capita each year. This collection- and weight-based recycling objectives aim to limit the number of hazardous chemicals dumped into landfills while also increasing the availability of recyclable resources, which indirectly encourages new product manufacturers to use fewer virgin materials. The measurement of e-waste gathered in underdeveloped and transition nations receives little attention. The reason for this is that e-waste collecting in the pre-reprocessing phases is generally done by the unorganized sector of scrap dealers/traders or peddlers. As a result, this data is hidden from the statistics gathering system, making e-waste measurement extremely difficult in developing and transitional nations. (Daniel Mmereki, 2016)
Solar module and battery trash are currently classed as normal electronic waste in India and are managed by the Ministry of Environment, Forests, and Climate Change. (Tyagi, 2020) India’s infrastructural capability for large-scale e-waste management is severely inadequate. Only roughly 1/5th of the entire quantity of e-waste created each year is recycled in the country’s few government-approved e-waste recycling centers. The Indian government offers a co-funded grant program that pays between 25% and 50% of the project expenditures for e-waste disposal facilities and e-waste business capacity building. However, just a small percentage of people have taken advantage of this program. Though some cities have e-waste collection centers but low or no information regarding these centers makes people end up giving their old e-waste to small retail shops to gain discounts on their new buy. (HindRise, N.A.) However, decentralizing the e-waste management business in a country like India can be a more efficient technique. Nevertheless, private players’ capacity to build up e-waste management systems in the formal sector is limited due to their inability to consistently obtain large volumes of e-waste. For example, in India, adopting effective recycling technology for e-waste management may need considerable upfront capital costs, which private firms cannot justify in the lack of assurance about procuring sufficient amounts of e-waste. But still, India can adopt several strategies like incentivizing formal e-waste recycling, training, and upskilling informal sector players, deploying readily available mature recycling technologies, and developing new innovative and cost-efficient technologies for e-waste recycling (HindRise, N.A.) to increase recycling business opportunities in India.
Considering the future growth of solar waste in India, more specialized private sector indulgence is required in the solar recycling industry. India needs to develop proper strategies for solar module recycling. This can be done by adopting various policies and following a mixed (centralized and decentralized recycling) system approach for solar waste management. This can prove to be an efficient and feasible solution for module recycling in India. This will also help in the development of new job and business opportunities and will certainly help India reduce its carbon emissions caused due to improper recycling of solar waste.
Policy Requirements
Policies are the driving force behind any development. Without a proper policy, a huge impact can be observed ultimately deteriorating the social and economic structure of a business and society. Therefore to implement a strategic business model for solar waste management in India, strong policy support is required. Despite the fact that India has Industrial Solid Waste Rules, solar panels are not included since solar PV waste is considered non-hazardous industrial waste, resulting in unregulated solar waste handling in the country. Therefore, India has to develop an integrated framework that can control the country’s solar PV waste management system. This can be done by adapting the framework used in other developed countries like the EU. (Suresh Jain, 2021)
The recycling process is a cost-intensive process, hence finance plays a crucial role in its development. Indian developers can pick from a variety of worldwide funding methods depending on their market share (Tyagi, 2020) and reduce their financial burden. Some other policy advancements such as reducing the dumping of solar panels in landfills or completely banning the use of landfills, provision of subsidies on solar panel recycling, and promoting refurbishing of slightly damaged panels could prove to be an advantageous solution in creating a sustainable solar industry in India.
Conclusion
Recycling is a vital process that helps in protecting the environment. With India expected to generate almost 34600-kilo tonnes of solar waste by 2030, recycling can prove to be the most feasible solution in restoring reusable and valuable materials from the damaged solar modules. With numerous recycling techniques currently available, industries can choose the most viable and economically feasible option depending upon the companies financial and infrastructural structure. The government, on the other hand, may help by giving subsidies and launching various initiatives aimed at expanding the scope of module recycling in India. This will also aid the country’s growth of new businesses and job prospects. India is now a growing leader in producing solar electricity and therefore, it should seek to develop and execute robust solar waste management policies in order to achieve its sustainability goals.
References
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