In the 2024 national "two sessions", the photovoltaic recycling industry is concerned, with several members of the photovoltaic recycling industry putting forward the development of views.
Inner Mongolia Environmental Protection Investment Group Co., Ltd. executive deputy general manager Zhang Liwen proposed: First, to accelerate the establishment of a standardization system covering the key aspects of equipment decommissioning, laddering, remanufacturing, recycling, green design and other key elements of recycling technology, safety and environmental protection, access standards, certification and evaluation. Secondly, we should strengthen the special support for scientific and technological innovation, in the field of battery recycling, support enterprises around the intelligent dismantling of power batteries, waste lithium battery crushing and sorting of high-value regeneration of advanced processes for technological innovation and upgrading. In the field of photovoltaic recycling, should strengthen the recycling technology results and promote the application, accelerate the industrialization of research results.
Li Yupeng, vice president of Liaoning University, proposed that: First, the distributed equipment recycling mechanism can consider the combination of online data and door-to-door inspection, and learn from the way of automobile end-of-life recycling. Second, actively explore and promote the establishment of recycling trading centers to promote the effective docking of the core links of the industrial ecology. Third, the introduction of relevant policies to encourage the enthusiasm of various types of enterprises in the recycling industry chain. Fourth, set up scientific and technological specialties, select demonstration bases and cultivate professionals.
The International Research Institute of Green Finance of the Central University of Finance and Economics proposes: first, to strengthen the input and research and development of green design and recycling technology, to transfer the cost of equipment recycling to all links of the industry chain, to increase the use of recyclable materials and to improve the convenience of equipment recycling. The second is to promote the development of wind power and photovoltaic equipment recycling industry with financial tools, take retired wind power and photovoltaic equipment recycling projects as the key support industry, develop a variety of green financial products and services, and provide financing facilities for qualified recycling enterprises, recycling projects and recycling technology R&D innovations. Thirdly, adopt policy support and incentives to improve the equipment recycling industry chain.
At present, the large-scale end-of-life period of PV modules has not yet arrived, and the module recycling industry is still in its infancy. Although a few organizations in Europe have already made breakthroughs in recycling technology, there is no evaluation standard for the relevant recycling technology, and the supervisory and management system, the standard system, and the policies and regulations have not yet been established, and the impact of the recycling process on the environment is not clear either. This paper starts from the structure of photovoltaic modules, summarizes the main problems existing in the module recycling industry at this stage, and puts forward the development trend of the photovoltaic module recycling industry in combination with the Law of the People's Republic of China on the Prevention and Control of Environmental Pollution by Solid Wastes, with a view to providing references for the relevant practitioners.
The structure of photovoltaic modules and the weight proportion of each component varies somewhat due to the different raw materials used by manufacturers. The structure of crystalline silicon solar modules is shown in Table 1, with the glass accounting for 68% of the entire module mass, the aluminum frame accounting for more than 17%, and the silicon wafer accounting for 3.46%, with the three accounting for more than 88%. It can be seen that the module contains a large number of potentially reusable resources. Aluminum frames, silver grid wires, tin-copper wires and glass can be processed to obtain industrial products, and rare metals such as indium, gallium, germanium and tellurium in crystalline silicon panels can be recycled for use in the production of new equipment.
Thin-film solar cells account for a small share of the market, but have broad development potential because of their low production costs, low consumption of raw materials, and the ability to absorb weak light. The main technologies of thin-film solar cells include silicon-based thin film, copper indium gallium selenide, cadmium telluride, gallium arsenide, chalcogenide cells and organic thin-film cells [11]. Among them, CdTe, indium gallium selenide and amorphous silicon thin-film photovoltaic modules have been marketed, accounting for 65%, 25% and 10% of the thin-film photovoltaic module market share, respectively. Indium gallium selenide thin-film PV modules use copper as the absorber layer, and the typical structure includes: glass, encapsulation film, transparent conductive oxide, absorber, back electrode, barrier layer, and backsheet, etc [1]. CdTe and amorphous silicon thin film photovoltaic modules use CdTe and amorphous silicon as the absorber layer, and the typical structure includes: glass, transparent conductive oxides, electrodes, encapsulation film, and backsheet. Thin film solar panels in glass aluminum and glass accounted for more than 95%, there are also potential reusable resources.
With the component end-of-life approaching, scholars at home and abroad on the components of the recycling technology and equipment for a large number of exploration, has formed a number of PV component recycling technology routes, but these new technologies, new technologies, new equipment to achieve market promotion there are still a series of problems, mainly in the following three areas.
(1) technically, the recycling process of pollutants generated and treated. The previous production of crystalline silicon battery components are mostly fluorine-containing backplane, after incineration will produce hydrogen fluoride and other toxic gases. At the same time, the structure of fluorine-containing backsheets in fluorine compounds is not easy to destroy, and cannot be degraded for a long time. Cadmium telluride (CdTe) thin-film batteries, which have greater potential for application, contain the highly toxic heavy metal cadmium, which can accumulate through the food chain and jeopardize human health. In addition, if the recycling process uses chemical solvents to dissolve ethylene vinyl acetate copolymer (EVA) in photovoltaic modules, although it can be recycled high-purity silicon, high-value metal materials, but also produces a large number of organic and inorganic acid, alkali waste liquid, more serious pollution of the environment.
(2) economic benefits, photovoltaic component recycling if it can not produce scale effect economic benefits are not obvious. At present, only a small number of enterprises can realize profitability with European PV Cycle as an example. In the European electrical and electronic waste (WEEE) new regulations and other policies to promote, PV Cycle since its inception to occupy 90% of the market share in Europe, the operating results of continuous growth. In China, due to the relatively small recycling scale, there are no professional enterprises to carry out, resource recovery technology is still in the laboratory research and development stage, and most of the technology has high energy consumption and poor economy, resulting in little market development momentum.
(3) Policy, the EU in 2012 will be PV modules as e-waste management, the requirements must be centralized collection of 85% of the used components, while 80% must be recycled. However, the domestic recycling of PV modules did not introduce relevant policies for the disposal of photovoltaic modules without a specialized supervision and management system, the sale of recycled materials is also no corresponding policy support, coupled with the current end-of-life volume is not large, the majority of enterprises in the wait-and-see phase.
