The evolution of solar photovoltaic technology in

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Phantom of photovoltaic - the evolution of global solar photovoltaic technology

in 1839, the physical phenomenon of photovoltaic conversion was discovered for the first time in human history. In 1959, the first polysilicon solar cell with photoelectric conversion efficiency of 5% came out; In 1960, silicon solar cell power generation was first incorporated into conventional electricity; In 1975, American scientists produced amorphous silicon solar cells; In the early 1980s, large-scale production of solar cells began

since the 1990s, under the pressure of energy crisis and global warming, with the continuous attention of countries to solar cell research, scientific research and industrial investment have increased, and a series of scientific research achievements have been made. The record of solar cell efficiency has been constantly refreshed, laying the technical foundation for large-scale industrial production. The global solar photovoltaic industry has grown rapidly as a sunrise industry

at present, solar energy utilization technology mainly includes solar thermoelectricity technology, solar water heating technology and solar photovoltaic technology. They are different ways of using solar energy. Solar hot water technology usually uses solar heat energy to provide hot water for families and buildings, which is convenient to use and low cost, but the energy utilization form is single and cannot be transmitted. At present, the application scale of solar water heaters in China has ranked first in the world. Solar thermoelectric technology is to gather solar energy and drive steam turbine generators to produce electric energy, such as tower power generation, dish power generation, etc. Solar thermal power is still on the eve of commercialization, and the investment cost is too high

solar photovoltaic technology utilizes the photovoltaic effect principle of semiconductor devices, and is the fastest-growing and most dynamic renewable energy utilization technology in recent years. At present, major countries in the world regard the development of photovoltaic power generation as the main form of using solar energy. With the reduction of the cost of solar cells and the improvement of conversion efficiency, it will become more and more obvious as the main form of solar energy utilization

solar cell technology has rich application space

gold rush in solar industry

reviewing the development process of solar industry, it can be considered as an early development stage before 2000. At that time, although there were many manufacturers to invest, only a few companies could maintain it because the technology development and business environment were not mature. From 2000 to 2005, it was the initial profit-making stage, and some companies were able to survive and start making profits. With the heating up of energy issues, the current solar energy industry has reached the gold rush stage, and many enterprises have begun to actively invest

at present, the mainstream product of solar cells is still crystalline silicon solar cells. Its research and development focus on reducing energy consumption, reducing production cost per watt, improving conversion efficiency and other aspects, so as to further promote the process of large-scale commercial use of solar power generation

1. The research on the new generation polysilicon process technology is unprecedentedly active

in addition to upgrading the traditional process technology, several new processes and technologies specialized in the production of solar grade polysilicon have emerged, mainly including: improving the Siemens method to further reduce costs; Metallurgical extraction of high purity silicon from metallic silicon; Direct preparation of high purity SiO2; Melting precipitation method; Reduction or thermal decomposition process; Chlorine free process technology, low temperature preparation of solar grade silicon from Al Si solution; Molten salt electrolysis, etc

2. Continue to move towards high efficiency, thin and large area

a. the conversion efficiency is getting higher and higher: 14% 18% 20%

b. the area of silicon wafer is getting larger and larger: from 103mm 103mm 125mm 125mm 156mm 156mm (current mainstream), it will reach 210mm 210mm in the next two years

c. the silicon wafer is getting thinner and thinner: 300 m 270 m 210 m 180 M. A 100 m thick process is under development

3. Transition of production equipment from semi-automatic to automatic and intelligent

a. improve the automation level of single machine, increase the batch loading volume, and improve the production efficiency of single machine

b. automatic transmission and detection between production line equipment to improve the productivity of the whole line

the main force in the next five years

in order to meet the needs of high efficiency, low cost and large-scale production and development of solar cells, the most effective way is to directly use thin-film materials instead of crystalline silicon materials, that is, to develop thin-film solar cells. Since the 1970s, kaishenbo pointed out that many types of thin-film solar cells have been developed internationally, such as CuInSe (CIS), CdTe films and organic films

thin film solar cells have the characteristics of safety, foldability, convenient connection, lightness, good heat resistance and not easy to be damaged. At present, the conversion efficiency of thin-film amorphous silicon solar cells produced on a large scale has reached about 8%, the conversion efficiency of CIS has reached 10% - 11%, and the laboratory conversion efficiency has exceeded 20%

at present, at least 40 countries in the world are carrying out practical technology research on low-cost, large-area and high-efficiency thin-film solar cells. With the continuous maturity of technology, thin-film solar cells will surpass crystalline silicon solar cells

new solar cells are emerging around issues such as reducing production costs, reducing energy consumption, improving photoelectric conversion efficiency, and increasing the proportion of energy regeneration. For example, quantum dot solar cells, quantum well solar cells, dye-sensitized cells, thermal photovoltaic cells and organic thin-film solar cells

high performance fiber production capacity, potential consumption, the world's first

comparison of crystalline silicon solar cells

China's solar cell technology still has room for development

after years of development, China has made great progress in the production of solar cell silicon materials, batteries and components, special equipment and other aspects. Polysilicon refining technology has made great progress, unit energy consumption has been reduced, and the manufacturing technology of crystalline silicon solar cells has reached the international advanced level

the key equipment of domestic crystalline silicon solar cell and module production line has made great progress, such as 8-inch diffusion furnace, plasma etcher, low-temperature drying furnace, high-temperature sintering furnace, washer, laminator, etc. have been widely used in domestic production lines instead of imported equipment. With the support of 973, 863 and other high-tech programs, China has made great scientific research progress in cadmium telluride and copper indium selenium thin film cells, sensitized solar thin film cells, polysilicon thin film cells and application systems

the industrialization of thin film batteries in China is also accelerating. Wuxi Suntech has established a thin-film solar energy R & D center in Shanghai, and it is expected that the production capacity will reach 50MW in 2009; Hebei Xinao introduced the world's leading SunFab thin film solar cell full set of automatic production line; Baoding Tianwei signed a contract with Oerlikon, an equipment manufacturer, to purchase equipment for thin-film solar module production line; Nankai University is cooperating to develop the industrialization technology of amorphous silicon/microcrystalline silicon laminated solar cells in Quanzhou, Fujian Province

although China's solar cell technology has made great progress, there is still a big gap compared with international advanced technology, mainly reflected in the following three points:

1 There is a big gap between the polysilicon refining technology and the advanced level

the production technology of polysilicon materials has been mastered in the United States, Japan, Germany and other countries for a long time, forming a situation of technical blockade and market monopoly against China. At present, the main traditional processes of polysilicon production in the world are: improved Siemens method, silane method and fluidized bed method. Among them, the capacity of polysilicon produced by improved Siemens process accounts for about 80% of the world's total capacity, and the monopoly and blockade of industrialized technology will not change in the short term. The gap with the international advanced level is mainly reflected in high energy consumption, low purity and low utilization rate of raw materials

2. There is a big gap between the industrialization and application technology of thin-film solar cells

compared with foreign advanced technology, the main problems we currently have are: insufficient investment in the research and development of thin-film solar cell technology, insufficient understanding of its development prospects, and lack of independent technological innovation, especially large-scale production technology. Compared with foreign countries, the industrial development is slow. At present, many foreign companies have begun to produce thin-film solar cells on a large scale, while only a few domestic enterprises such as Suntech and Baoding Tianwei have begun their industrial layout

3. There is a big gap between high-end equipment of crystalline silicon battery and thin-film battery manufacturing equipment

advanced equipment in the United States, Europe, Japan and other countries is characterized by high production capacity and high degree of automation. Compared with these experimental equipment, which mainly depends on what customers need to do, the degree of automation of domestic equipment is not high. High end equipment such as crystal silicon battery automatic silk printing machine and automatic testing sorting machine rely on imports. Thin film solar cell equipment has not yet started

link: three categories of solar cells

according to the maturity of technology development, solar cells can be divided into three categories: crystalline silicon solar cells, thin-film solar cells, and next-generation new solar cells

1. Crystalline silicon solar cell

the manufacturing process of crystalline silicon solar cell is transformed from the mature microelectronic process. It has the advantages of mature silicon material, process and manufacturing technology, high conversion efficiency, stable performance and so on. The conversion efficiency of monocrystalline silicon solar cells produced on a large scale can reach 16%-17%, and the maximum conversion efficiency in the laboratory can reach 24.4%. The head of the robot arm is composed of 16 rods similar to the super large sewing spool. The conversion efficiency of large-scale polysilicon solar cells can reach more than 14% - 15%, and the highest conversion efficiency in the laboratory can reach 16.6%. However, compared with conventional energy, they have the problems of high cost and high manufacturing energy consumption

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