Analysis of the development status of China's photovoltaic industry in 2018 and forecast of future development prospects

Processing silicon wafers into solar cells is the core step to realize photoelectric conversion. The manufacturing of solar cells is a capital- and technology-intensive industry. Companies are required to follow up on new cell manufacturing technologies to improve cell efficiency. The higher the conversion efficiency of solar cells, the lower the production cost, which is more conducive to solar power generation.

system application. According to the different materials used, solar cells can be divided into three categories: the first category is crystalline silicon solar cells, including monocrystalline silicon and polycrystalline silicon; the second category is thin film solar cells, including silicon-based thin films, compounds and organics; The third category is new solar cells, including tandem solar cells, multi-bandgap solar cells, and hot carrier solar cells. Due to the scarcity or toxicity of raw materials, low conversion efficiency and poor stability in compound and organic thin-film solar cells, and the third-generation solar cell technology is not yet mature, the currently used solar cells mainly include monocrystalline silicon, polycrystalline silicon and Amorphous silicon thin film solar cells.

Classification of solar cells

Judging from the changes in the market share of various solar cells, the high cost performance of polysilicon has enabled it to maintain a good market share, especially in 2014 and 2015, the proportion has increased significantly, while the market share of monocrystalline silicon and thin film solar cells The proportion has decreased. But that changed in February 2016. Benefiting from the drop in the cost of monocrystalline silicon products and the promotion of the national "Top Runner Program", the market share of monocrystalline silicon cells in China has continued to increase. In 2015, the global mono market share was about 18%. The conversion efficiency of photovoltaic cells is the core competitiveness of battery companies. During the "Twelfth Five-Year Plan" period, the technological progress of my country's photovoltaic cell manufacturing industry continued to accelerate, and the product quality ranked among the top in the world. As of July 2017, the conversion efficiencies of large-scale monocrystalline silicon and polycrystalline silicon solar cells11 in my country reached an average of 19.8% and 18.5%, respectively. The improvement of photoelectric conversion efficiency in the future mainly depends on the upgrading of preparation technology. Screen-printed all-aluminum back-field solar cells (Al-BSF) have dominated the photovoltaic cell technology market over the past decade. This technology will maintain its leading position until 2020 due to its good performance and low production costs. However, with the advancement of fabrication technology, other high-efficiency batteries will bring competitive pressure to it. At present, high-efficiency battery technologies with mass production application basis include PERC (Passivated Emitterand RearContact, passivated emitter and back contact cell), PERT (Passivated Emitterand RearTotally-Diffused Cell, passivated emitter back fully diffused cell), HIT ( Hetero-junction with Intrinsic Thin-layer, intrinsic thin film heterojunction battery), IBC (Interdigitated Back Contact, interdigitated back contact battery), etc. At present, the mature high-efficiency battery technology is PERC technology. PERC cells only need to add two processes to the existing all-aluminum back-field solar cell production line. Compared with other high-efficiency solar cells, it is easy to upgrade and transform on the basis of the existing solar cell production line. The potential comprehensive cost is low, and it is easier to realize industrialization. . As of July 2017, the photoelectric conversion efficiency12 of mono- and polycrystalline cells using PERC cell technology can be increased to 20.5% and 19%, respectively. At present, JinkoSolar, Canadian Solar, Trina Solar, JA Solar, Solar Energy, SolarWorld, and Hanwha QCells have successively increased their PERC production capacity. In addition, battery technologies such as HIT and IBC also represent the development direction of high-efficiency batteries. my country has successfully surpassed Europe and Japan to become the world's largest producer of solar cells. In 2016, my country's solar cell output exceeded 49GW, a year-on-year increase of more than 19.5%, accounting for 71.01% of the world's solar cell output. Production technology has continued to improve, and production costs have continued to decline.