针对晶硅光伏组件寿命期后大规模退役问题，开展光伏组件环保处理和回收的关键技术及装备研究与示范试验，实现主要高价值组成材料的可再利用。针对目前行业各主流产品类型，开发基于物理法和化学法的低成本绿色拆解技术，掌握高价值组分高效环保分离的技术与装备；开发新型材料及新结构组件的环保处理技术和实验平台；研究组件低损拆解及高价值组分材料高效分离等关键设备，实现退役光伏组件中银、铜等高价值组分的高效回收和再利用。

In recent years, driven by technological progress, China's photovoltaic power generation industry has achieved rapid development, and the industrial scale and technical level have reached the world leading level. During the "fourteenth five year plan" period, careful planning, layout in advance and strengthening photovoltaic technology innovation and industrial upgrading are important guarantees to improve the core source power and promote the high-quality, low-cost and large-scale development of photovoltaic power generation.



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Development status and trend of photovoltaic power generation technology



（1） Development status of photovoltaic power generation technology in the world



Vigorously developing renewable energy has become the leading direction and concerted action of the global energy revolution and climate change response. In recent years, photovoltaic power generation, as an important renewable energy power generation technology, has achieved rapid development, and has become a clean, low-carbon and price competitive energy form in many countries. In 2020, the global installed capacity of photovoltaic power generation will increase by 127million kW, and the cumulative installed capacity will reach 707million kW.



Crystalline silicon cell is still the mainstream technology of photovoltaic cell industrialization, and new cells are developing rapidly. As the core component of the photovoltaic industry, photovoltaic cells can be divided into crystalline silicon cells, thin film cells, perovskite cells, organic cells, etc. according to different processes and raw materials. Among them, crystalline silicon cells occupy the main body of large-scale production and application of photovoltaic cells because of their high conversion efficiency, rich sources of raw materials, non-toxic and harmless advantages.



In recent years, the wide application of perc (emitter passivation and back contact) technology has further promoted the improvement of the conversion efficiency of crystalline silicon batteries. On the other hand, the new battery represented by perovskite battery has become a worldwide research hotspot. The conversion efficiency has been rapidly improved. The maximum conversion efficiency in the laboratory has been close to that of crystalline silicon battery. The industrialization process has been gradually promoted, but it still faces challenges in large-scale application and device stability.



The refinement level of photovoltaic system has been continuously improved and the application modes have been diversified. The capacity of photovoltaic system subarray has been continuously increasing, the application proportion of 1500 V photovoltaic system has gradually exceeded that of 1000 V system, the grid connection safety and reliability standards have been continuously improved, and the power generation capacity and power quality of photovoltaic power stations have been continuously improved. The scale of composite application forms such as "photovoltaic + agriculture", "photovoltaic + animal husbandry", "photovoltaic + Architecture" and "photovoltaic + fishery" has been expanding. The in-depth integration of photovoltaic power generation and power grid such as micro grid and smart grid has gradually become a new business type of the power industry.



（2） Development trend of photovoltaic power generation technology in the world



Countries around the world continue to deepen the innovation of the whole industrial chain of photovoltaic power generation. As a major strategic measure to promote the development of emerging industries, they achieve cost reduction and competitiveness improvement through R & D covering all aspects of advanced materials, manufacturing and system application.



Photovoltaic core devices are developing towards high efficiency, low energy consumption and low cost. Crystalline silicon cells have built a complete industrial chain and will continue to occupy the main share of photovoltaic cell production. In the future, they will further develop towards higher conversion efficiency, less raw material consumption, lower energy consumption and lower manufacturing cost. Perovskite cells and laminated cells are the important development direction of photovoltaic cell technology in the future. Countries all over the world focus on this aspect, focus on improving device performance and stability, and promote industrialization layout. After solving the problems of large area and stability, perovskite cells are expected to change the industrial pattern of photovoltaic application market.



Photovoltaic applications are developing towards multiple utilization scenarios. Countries around the world actively promote the development of photovoltaic building integration, floating photovoltaic, photovoltaic + agriculture, photovoltaic shed and other new application forms in combination with their own actual situation. The related specific product technology and joint operation control technology have become the research focus.



（3） Current situation of photovoltaic power generation technology in China



During the "13th five year plan" period, driven by the rapid expansion of industrial scale, China's photovoltaic power generation technology has achieved rapid development, and the industrialized mass production technology of photovoltaic cells, modules and other key components has reached the world leading level; Production equipment and technology have been upgraded continuously, and localization has been basically realized; The complete technology of photovoltaic power generation system has been continuously optimized and improved, and the intelligent level has been significantly improved.



Photovoltaic cell module technology has been rapidly iterated, and the industrialized manufacturing level is world leading. By the end of the 13th five year plan, China's photovoltaic cell manufacturing has basically realized the upgrading from the traditional "polycrystalline aluminum back field" technology to the "single crystal perc" technology. The average conversion efficiency of mainstream mass-produced crystalline silicon cells has increased from 18.5% at the beginning of the 13th five year plan to 22.8%, realizing leapfrog development.



The industrialization level of new crystalline silicon high-efficiency battery and module technologies such as TOPCON (tunneling oxide passivation contact), hjt (heterojunction), IBC (back electrode contact) has been continuously improved. The leading enterprises have repeatedly refreshed the world record of industrialized production conversion efficiency, and have large-scale production capacity and strong international competitiveness. Perovskite and other new generation high-efficiency battery technologies keep pace with the world. Research institutions have repeatedly created world records for the conversion efficiency of perovskite battery laboratories. Some enterprises have carried out research on industrialized production and repeatedly refreshed the conversion efficiency records of industrialized production components.



The level of photovoltaic power generation manufacturing equipment has been significantly improved, and localization has been basically realized. China's photovoltaic equipment has realized the development from low-end to high-end, the degree of product customization has been continuously improved, the ability of high-capacity and efficient automation has been continuously improved, and the degree of automation, digitalization and networking has promoted the transformation from photovoltaic manufacturing to photovoltaic intelligent manufacturing. Production equipment for polysilicon silicon wafer, battery wafer and module has been basically localized.



Photovoltaic power generation system technology has been continuously optimized, and intelligent operation and maintenance has helped improve power generation capacity. A large number of new technologies have been applied to the overall design and system level optimization of photovoltaic power plants. The adoption of PV support tracking system and 1500 V voltage has effectively improved the actual power generation capacity of the PV power generation system; Intelligent robots, UAVs, big data, remote monitoring and advanced communication technologies have been used in the operation of the power station.



（4） Development trend of photovoltaic power generation technology in China



As the largest photovoltaic power generation application market in the world, China has become an incubator for the industrialization and application of various new photovoltaic cell technologies. In the future, China will continue to focus on the key development direction of international photovoltaic power generation technology and lead the sustainable innovation and development of global photovoltaic power generation industrialization technology.



The efficiency of photovoltaic cells was further improved. Crystalline silicon battery will remain dominant for a period of time, and perc technology will be the main technology. The n-type crystalline silicon cell adopting TOPCON or hjt technology is expected to become the next mainstream photovoltaic cell technology after comprehensively considering efficiency, cost and scale and having good market competitiveness. Perovskite cells and other high-efficiency photovoltaic cells based on new material systems as well as laminated cells are research hotspots. After the industrialization technology is gradually mature, it is expected to bring the next step improvement of photovoltaic cell conversion efficiency.



High efficiency and high reliability of photovoltaic modules go hand in hand. Half chip technology, tile stacking technology, multiple main grids and other component technologies will be further widely used. Double sided components will gradually become the mainstream of the market, improving component efficiency and power generation capacity. New packaging technologies and materials further improve the reliability of components.



Photovoltaic power generation system is intelligent and diversified. The inverter will develop towards high-power single machine, high-voltage access and intelligence, continuously deepen the integration with energy storage technology, and continuously improve the level of intelligent operation and maintenance technology. Photovoltaic building integration and other new scene application technologies have been continuously improved, and the development space for photovoltaic power generation has been expanded.



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Development direction and objectives of photovoltaic power generation technology in the "14th five year plan"



It is predicted that in order to achieve the goal of carbon peak and carbon neutralization, China's installed capacity of photovoltaic power generation will need to reach 900million to 1billion kW by 2030; By 2060, it will need to reach 3-3.5 billion kilowatts. Photovoltaic power generation faces many challenges while facing unprecedented development opportunities and development space. Photovoltaic power generation technology innovation will become a key factor to deal with these challenges.



Strengthen technological innovation, improve the value of comprehensive land use, and promote the large-scale development of photovoltaic. It is estimated that the exploitable potential of solar energy in China can reach the order of 100 billion kilowatts. However, considering the ecological red line and basic farmland factors, about 44% of the land area can not be used for the development of new energy projects such as photovoltaic. The State Forestry and grassland administration and other departments have increasingly standardized the requirements for the development of new energy. Under the new situation, it is urgent to further improve the power generation capacity per unit area of photovoltaic power generation, reduce the demand for construction land for photovoltaic power generation projects, and strengthen the comprehensive utilization of land to improve the efficiency of land use.



On the one hand, through the application of new materials and new technologies, improve the conversion efficiency of photovoltaic cell modules and enhance the power generation capacity per unit area of photovoltaic modules; On the other hand, continuously optimize the design and construction level of photovoltaic power generation system, carry out application mode innovation, strengthen the intelligent management and operation and maintenance of photovoltaic power stations throughout their life cycle, and improve the power generation efficiency of photovoltaic power stations.



The grid connection performance of photovoltaic power generation is further improved to meet the requirements of high permeability applications. With the continuous improvement of the penetration rate of photovoltaic power generation in the power grid, the power system will meet the challenges of security, stability, power quality, economy and so on. As an important part of building a new power system with new energy as the main body, it will become an important research direction to improve the power prediction accuracy of photovoltaic power generation, improve the grid related performance of photovoltaic system, such as active support and resistance to power system disturbance.



The integrated development of distributed photovoltaic and other fields will become an important part of photovoltaic power generation in the future. While steadily promoting the construction of large-scale photovoltaic base, new application forms such as photovoltaic building integration, photovoltaic and transportation, and new infrastructure construction and construction have put forward new requirements for photovoltaic product performance and photovoltaic power generation system. It is necessary to continue to promote the development of photovoltaic power generation related technologies in combination with specific scenario application conditions.



Improve the green industry chain of photovoltaic power generation in the whole life cycle. With the rapid growth of the installed capacity of photovoltaic power generation in China in recent years, the recycling of photovoltaic modules at the end of their life has also attracted increasing attention. In combination with the growth of China's photovoltaic power generation scale, it is expected that China will usher in the first peak demand for photovoltaic module recycling around 2040. In the long run, under the requirements of carbon peaking and carbon neutralization goals, it is urgent to improve the harmless recovery and treatment technology of expired photovoltaic modules, promote industrialization, and complete the last link of the green industrial chain in the whole life cycle of photovoltaic power generation.



Strong production capacity ensures the implementation of photovoltaic development goals. In 2020, China's photovoltaic module production capacity will be 244.3 million KW, and the actual output will be 124.6 million KW. About 60% of the modules will be sold overseas. During the "fourteenth five year plan" period, it is still necessary to further improve the capacity guarantee of photovoltaic products. On the one hand, it is necessary to further develop the intelligent manufacturing technology of photovoltaic cells, modules, inverters and other core components to improve the intelligent production level, production efficiency and production capacity; On the other hand, it is necessary to further carry out technical research, break through the localization technology of a small number of key manufacturing equipment parts as soon as possible, and eliminate the potential bottleneck of development.



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Prospects for the development of photovoltaic power generation technology during the "14th five year plan"



Based on the demand analysis of the technology development of the photovoltaic power generation industry under the situation of carbon peak and carbon neutralization, during the "14th five year plan", China's photovoltaic power generation technology is expected to continue the rapid development momentum of the "13th five year plan". Under the guidance of the overall national development goals, research and breakthroughs will be focused on the key problems existing in the industrial chain, "making up for weaknesses and forging long plates", so as to continuously improve the technical level of China's photovoltaic power generation industry and help carbon peak Realization of carbon neutralization goal.



（1） Developing high efficiency and low cost photovoltaic cell technology



Build a new business form of high-efficiency and low-cost crystalline silicon cells, further improve the conversion efficiency of crystalline silicon cells, promote the wide application of high-efficiency new technologies, and improve the power generation capacity per unit area of photovoltaic power generation system. First, focus on the research on the low-cost and high-quality industrialized manufacturing technology of new crystalline silicon batteries such as TOPCON, hjt and IBC, develop the manufacturing technology of key materials, processes and equipment for high-quality industrialized production, further improve the industrialized production efficiency and battery conversion efficiency, reduce production costs, and promote the large-scale application of high-efficiency crystalline silicon batteries, including low-cost and high-efficiency cleaning technology, high-quality passivation technology Low cost Metallization Technology. The second is to study the manufacturing technology of low-cost and high-quality silicon wafers. Focus on breakthrough in low-cost and efficient silicon particle preparation, continuous crystallization, n-type and gallium doped p-type silicon rod preparation technology, and strengthen the support for large-scale development from the source of the industrial chain. At the same time, develop large-size ultra-thin silicon wafer cutting technology, master ultra-thin silicon wafer cutting process, complete the development of supporting equipment, related main and auxiliary materials and supporting technology research, realize the stable cutting and output of large-size ultra-thin silicon wafer, and support the development of low-cost silicon photovoltaic cells.



（2） Strengthen the research on Preparation and industrialized production technology of high efficiency perovskite battery



Focusing on the development hotspot of photovoltaic technology in the world, we will carry out centralized research on the preparation and industrialized production technology of new perovskite cells, and promote the large-scale production of single junction perovskite cells. At the same time, develop high-efficiency laminated battery process, break through the efficiency limit of single junction cells, and realize the step-by-step improvement of photovoltaic cell conversion efficiency. The first is to study the complete preparation technology of large-area high-efficiency, high stability and environment-friendly perovskite batteries, develop high reliability component cascade and packaging technology, and develop mass production process equipment based on solution method and physical method, so as to realize the industrialization and mass production of high-efficiency single junction perovskite batteries. Second, carry out research on the preparation technology of high-efficiency laminated cells such as crystalline silicon / perovskite and perovskite / perovskite, optimize the design and preparation process of laminated structure, greatly improve the power generation efficiency of photovoltaic cells, and gradually realize the industrialized mass production capacity.



（3） Promote the grid connection performance of photovoltaic power generation



Carry out research and demonstration test on new high-efficiency and high-capacity photovoltaic grid connected technology, break through the key technology of medium voltage grid connected inverter, carry out research on coupling resonance mechanism and suppression strategy under weak current network conditions, optimal adaptive virtual synchronization technology combining active power reserve and energy storage unit, optimal design of high-power density medium voltage power generation module and empirical test technology of system integration, and develop AC direct mounted medium voltage grid connected inverter. Break through the bottleneck of large-scale photovoltaic high-efficiency and stable DC collection technology, carry out research on high-power and high-efficiency DC boost converter topology, self-regulation control technology, intelligent series / parallel control of multiple DC converters and intelligent operation control technology of multiple scenarios, and develop high-power DC converters. Carry out research on key technologies such as transient steady-state characteristics and simulation between photovoltaic power generation and power system to improve the grid connection performance of photovoltaic power generation.



（4） Promote the application of photovoltaic building integration and equal distribution technology



Promote the technological innovation of distributed photovoltaic applications such as "photovoltaic +", expand the field of distributed photovoltaic applications, and boost the high proportion development of photovoltaic power generation. Focus on technical research on photovoltaic building integration products in various forms, such as photovoltaic roofs and glass curtain walls, and comprehensively consider building structure, strength, fire protection, safety performance and other factors to meet the needs of large-scale applications. At the same time, we will carry out research on product modularization and lightweight technology, improve relevant technical standards and specifications, and promote the integration of photovoltaic buildings and the large-scale application of photovoltaic power generation and comprehensive utilization in other fields.



（5） Strengthen photovoltaic smart manufacturing and equipment localization



Build a smart photovoltaic production and manufacturing system, improve production and manufacturing capacity, carry out key centralized research, break through the localization technology of key equipment and parts, solve potential production technology bottlenecks, and ensure the capacity supply of future photovoltaic core products. First, improve the production of basic materials such as polysilicon and the intelligent level of photovoltaic cell and component manufacturing, and improve the supply capacity of intelligent photovoltaic terminal products; Second, independently research and develop core equipment for high-quality heterojunction batteries, and break through manufacturing technologies such as molecular pumps, vacuum valves, power supplies, vacuum meters and other vacuum equipment standard parts and performance testing equipment for high-quality manufacturing equipment; Third, break through the large-scale application technology of domestic power modules, controller chips, digital signal processors and other key components for photovoltaic inverter; Fourth, master the manufacturing technology of key materials such as low-temperature silver paste and sputtering target for heterojunction photovoltaic cells.