Collect junk or help low carbon? Welcome the coming retirement tide of photovoltaic modules

In 2030, the global recovery of photovoltaic modules will reach 8 million tons. Facing the coming retirement tide, how to get through the "last mile" of the photovoltaic green industry chain? " A person in charge of a photovoltaic module recycling enterprise in Jiangsu told reporters.

According to him, photovoltaic module recycling is mainly done by some small enterprises, and the recycling components are mainly inventory components, power plant demolition components, debt-paying components, demolition legacy components. These second-hand components are sold to rural areas or underdeveloped countries such as Africa and South America, which are still profitable.

As for the decommissioned components, in his view, the logic of waste recycling is similar, removing the frame, aluminum and glass, and burning or landfilling the rest.

But some people do not think so, "Photovoltaic module recycling is not a junk collection, anyone can do it." Lu Fang, senior engineer of the Institute of Electrical Engineering of the Chinese Academy of Sciences and Secretary-General of the Photovoltaic Commission of the China Green Supply Chain Alliance, stressed in an interview with the media.

Lv Fang is the godmother of China's photovoltaic recycling work. She has been engaged in photovoltaic recycling research and industrialization for ten years. In her view, photovoltaic module recycling is an important part of the photovoltaic industry to achieve carbon neutrality. In the future, as the "last mile" of the photovoltaic green chain, module recycling will form a new industry of 100 billion.

On the one hand, small workshops are piecemeal, on the other hand, the "100 billion blue sea" is rarely visited, and the recycling of photovoltaic modules has formed a rather paradoxical situation. Component Retirement Tide Is Approaching, Who Will Recycle? Where to recycle? How to make a profit? Future, Every year, a large number of new installations and a large number of retired components will become the

However, considering the rapid technology iteration of photovoltaic modules, the photovoltaic modules 20 years ago and today's 22% + conversion efficiency modules are no longer the same, after the decline of subsidies, power plants have a strong willingness to replace more efficient modules in advance. China's early construction of " experts have pointed out that in the past 10 years, the cost of photovoltaic modules and photovoltaic systems has dropped by more than 90%. With the great progress of technology and the great decline of LCOE, it is a big probability event that the existing photovoltaic power plants are replaced before their life (25 years). Under the superposition of various factors, the retirement tide of photovoltaic modules will come earlier.

According to relevant data, the proportion of glass, aluminum and semiconductor materials in crystalline silicon photovoltaic modules can reach 92%, and it also contains about 1% of precious metals such as silver. If fully recovered, 1.45 million tons of carbon steel, 1.1 million tons of glass, 540,000 tons of plastic, 260,000 tons of aluminum, 170,000 tons of copper, 50,000 tons of silicon and 550 tons of silver can be obtained from waste photovoltaic modules by 2030.

Greenpeace predicts that the cumulative value of raw materials available through PV module recycling technology will reach 7.683 billion yuan, and by 2040, the cumulative recoverable value will be as high as 1.

For this reason, the China Photovoltaic Industry Association has issued a document calling for a scientific and reasonable calculation of the growth trend of the PV module recycling market. In order to gather industry consensus and promote the government and enterprises to advance the layout of policy formulation, commercial layout and other related work.

In addition to the huge market scale in the future, component recycling also plays an important role in carbon reduction in the whole industry chain. generates green electricity, the whole life cycle of photovoltaic modules from production to installation and operation to recycling will produce carbon emissions, which are also known as carbon footprint." It is becoming a green pass for photovoltaic importing countries to inspect the admission qualifications of photovoltaic enterprises in China.

data green" According to the calculation of the Peace Organization, the production process of 1 kW (size: 1650 X 990 X 40 mm) photovoltaic panels will produce 428. If the modules can be 100% recycled, about 428.1 kW is equivalent to 4 modules, each of which is 19.8 kg, totaling 79. Every 79.2kg of waste PV modules can reduce 428.8kg of carbon emissions, so 1 ton of waste PV modules can reduce about 5.

In addition, there is a lack of a sound recycling system for retired PV modules, and small workshops often incinerate and landfill the remaining parts after dismantling the modules, which will cause a lot of environmental pollution.

Direct burial will cause great damage to the soil environment, and the heavy metals contained in photovoltaic modules will gradually leak into the soil, thus causing harm and pollution to groundwater, vegetation and animals, and finally endangering human life and health through bioaccumulation.

In addition, photovoltaic panels will release toxic gases such as sulfur dioxide, hydrogen fluoride and hydrogen cyanide during incineration. These gases are irritating to the human respiratory system, and long-term inhalation may cause poisoning or carcinogenesis.

Untreated waste photovoltaic modules can also cause light pollution, damage human retina and iris, increase the incidence of cataract, and cause insomnia, neurasthenia and other mental diseases.

It is estimated that in 2040, China's retired photovoltaic modules will produce about 300000 tons of scrap copper and 60000 tons of scrap silver. If it is not recycled, it will cause huge waste of resources and environmental damage, and the recycling of photovoltaic modules is imminent. The

profit model needs to be solved

. The market prospect is bright, the goal of carbon reduction is urgent, and the necessity of photovoltaic module recycling is self-evident. However, due to the lack of scale effect, the profit of module recycling is still pitiful, but the cost remains high. He Shuangquan, president of

Wuxi Suntech Solar Power Co., Ltd., said that at present, a large part of photovoltaic modules are built in remote northwest areas or on roofs, which makes it difficult to recycle modules and high logistics costs. Therefore, the business radiation scope of recycling enterprises is very small, and they can only go around in the province.

In addition, the technology is not yet mature, the investment consumption is large, the purity of recycled materials is not high, and the cost of recycling waste photovoltaic modules is high.

In the case that recycling enterprises have to pay for decommissioned equipment, the enthusiasm of enterprises to participate in component recycling is not high and unprofitable, which leads to little momentum for market development.

In addition, the acquisition of scrap components is also a problem. At present, the centralized photovoltaic power plants in China are mainly held by dozens or hundreds of state-owned enterprises and large private enterprise investors. There is no clear standard for the scrap of photovoltaic modules. It is not easy for third-party photovoltaic module recycling enterprises to establish cooperative relations with these large enterprises. Improper handling will also lead to disputes over the loss of state-owned assets.

At present, there are few domestic enterprises engaged in component recycling, such as State Power Investment Corporation, Jingke Energy, Greenmay, Yingli Energy and Hanhua Group, which claim to have mastered the most advanced panel recycling technology in the world, but at present, only the factory demonstration line is the main one, and the commercial operation has not been realized.

European WEEE regulations and other policies, PV CYCLE has occupied 90% of the European market share since its establishment, and its operating performance has been growing continuously. Hundreds of recycling points have been set up in Europe, and the alliance has recycled more than 60000 tons of waste crystalline silicon photovoltaic modules, with an annual processing capacity of about 1.

Under the current WEEE system of the European Union, each module carries a code to facilitate the tracking of the whole process from production to recycling. So that component recycling enterprises can carry out planned statistics and recycling.

This shows that in the early stage of industry development, supporting policy support is particularly critical, "At present, our hard power and hard technology are basically ready, but the soft environment needed for the growth and development of an industry and market is still poor." Lu Fang said in an interview with the Beijing News.

At present, although China has a perfect policy system for the recycling of waste electrical and electronic products, it does not cover photovoltaic module products, and the recycling of photovoltaic modules lacks a perfect treatment standard system, module waste standards and life cycle management information.

Faced with the coming wave of module retirement, relevant departments are working hard to study and promulgate relevant policies to guide and require the photovoltaic module recycling industry to fill this gap.

but the Standardized group standards have not yet been quantified. Lu Fang believes that the overall indicators of the green supply chain should be digitized and combined with the quantitative indicators of carbon reduction to complete the carbon inventory, calculate the carbon reduction space, and promote carbon reduction in the whole industry chain. In February

last year, the Ministry of Ecology and Environment issued the Implementation Plan for Accelerating the Comprehensive Utilization of Industrial Resources, which made it clear that waste photovoltaic modules and wind power blades belong to emerging solid waste, which is managed by the Ministry of Ecology and Environment according to the number classification. In January last year, the

Ministry of Industry and Information Technology issued the Announcement of Research Projects on Industrial Energy Conservation and Green Standards in 2022, which also mentioned the technical specifications for life cycle assessment of photovoltaic glass, film, frame, backplane, battery and silicon wafer production.

Lu Fang has disclosed to China Business News that the current standards for the rejection of photovoltaic modules have passed the final round of review and will soon be introduced. Moreover, the producer extension system to solve the problem of "who will recycle" is also under study, and component recycling has been on the eve of the outbreak.

According to the Photovoltaic Committee of China Green Supply Chain Alliance, the recycling process of photovoltaic modules includes three parts. First, the recycler transports the photovoltaic modules to the processing plant, and then separates the valuable materials of photovoltaic modules, including glass, metal and its compounds; Finally, material manufacturers such as downstream metal refining companies purify and refine the recycled materials, and finally form high-value materials to enter the market again.

Aluminium frames are sent to aluminium refineries; waste plastics can be used as fuel in cement plants; recycled silicon can be reused in the precious metals industry; and the remaining cables and connectors are crushed and sold as copper beads.

It is worth noting that in the treatment process, some materials (such as EVA and other polymers) in the components can generate heat, which can be recovered by advanced technology to form considerable energy power. The core step of the

component recycling process is the separation technology of the factory production line. Due to the late start of component recycling industry and insufficient R & D investment, the recovery of precious metals in the form of complex alloys in products is still very difficult, and the technology still needs to be broken through.

At present, there are three main technical routes for module recovery: physical method, chemical method, and pyrolysis method. The front and back sides of the PV module are fixed by EVA film. To separate the aluminum frame, glass and cells in the module and fully recover the precious metals, it is very important to eliminate the adhesion of Eva. The layered fixation of Eva is carried out under high temperature vacuum compression, which has high stability, which brings a lot of challenges to the module recovery.

The physical separation method is to crush the laminate into smaller particles, sort out the glass particles and welding strips, grind the remaining parts, and separate the metal, backplane, EVA or POE particles by electrostatic separation. Although the physical method is simple to operate, the efficiency of resource recovery is low. After the module is broken, the film components are still mixed in the recycled materials, which results in the low purity of the recycled materials. The simple physical method is mainly used by some small enterprises. A photovoltaic module recycler in Shandong told reporters that this technology can not effectively complete the recovery of precious metals in the module.

The chemical method mainly aims at the metal component of the recycling component, and uses organic acid and inorganic acid to directly dissolve or swell the EVA adhesive film to realize the separation of the glass layer and the EVA. However, EVA will break the cell after expansion and there is a problem of organic waste liquid treatment. The toxicity of common separation reagents (toluene, o-dichlorobenzene, trichloroethylene, etc.) Also limits the large-scale use of chemical methods. In addition, this method costs a lot.

Pyrolysis is the most effective method for separating EVA, which separates and recycles glass by thermally decomposing the EVA encapsulation layer between the glass and the photovoltaic cell; the plastic in the module can be pyrolyzed into acetic acid, propane, propylene, ethane, methane, and other combustible oils and gases in an inert gas environment. However, fluoride in the backsheet is released during direct thermal processing and pollutes the environment. In addition, this method only decomposes EVA, but can not effectively remove the glass and backsheet, which hinders the release of organic matter during the pyrolysis of EVA, which may lead to the breakage and mixing of glass and solar cells and reduce the resource recovery rate. The

three recovery methods have their own advantages and disadvantages, but generally speaking, the existing technical system is still unable to achieve green recovery, especially for the treatment of fluorine-containing backplanes, because fluorine-containing backplanes contain halogen elements, if incinerated, hydrogen fluoride and other toxic gases will be produced, and fluorine is also difficult to treat by other methods. The chemical structure of fluorocarbons is so strong that they can not be degraded in the soil for 1000 years.

More and more research institutions began to use the composite process to treat waste PV modules, and reasonably select the process according to different types of PV modules to effectively improve the efficiency of resource utilization. In the future, with the inclination of policies, funds and talents, the technology is expected to make further breakthroughs.

"Carbon peak before 2030 action plan" has "to promote retired photovoltaic modules and other emerging industries waste recycling" into it, in the context of the double carbon target, the rapid growth of the photovoltaic industry brought about by the problem of component recycling will cause more concern, in the policy level, the state should speed up the introduction of relevant standards. Introduce supportive tax policies and patent protection. In terms of enterprises, photovoltaic manufacturing enterprises are encouraged to build a green low-carbon model of the whole chain of warehousing, procurement, transportation and disposal from production to recycling. The industry needs to cooperate actively to get through the "last mile" of green photovoltaic.