Reflections on the accelerated development of solar photovoltaic industry (2)

Second, the crystalline silicon battery is still the mainstream of solar photovoltaics for a long time. Currently, solar photovoltaic cells mainly include crystalline silicon cells and thin-film batteries. Crystalline silicon cells are further divided into monocrystalline silicon solar cells and polycrystalline silicon solar cells, and thin-film solar cells basically. Divided into non-microcrystalline silicon thin film batteries, copper indium gallium selenide thin-film batteries and cadmium telluride thin-film batteries three categories.

(A) The characteristics of crystalline silicon solar cells. At present, the crystalline silicon solar cell is a type of solar cell with the fastest development speed, the most mature technology, and the largest industrialization. The conversion efficiency of crystalline silicon cells made by the solar energy research institute in Freiburg, Germany, exceeds 23%; the Institute of Physics, India proposes an efficient solar cell model with internal recession that can increase the conversion efficiency to 28.6%; The conversion efficiency of the grooved buried gate electrode 2cm×2cm crystalline silicon cell reached 19.79%. Monocrystalline silicon solar cells have the highest conversion efficiency, but they have high requirements for the purity of silicon, and the complexity of the process and material prices make the cost higher. Polysilicon solar cell materials have lower requirements in terms of crystal quality, purity, etc. The production cost is lower than monocrystalline silicon, and the conversion efficiency in industrial applications has reached the level of 15-20%, so polysilicon has become the most widely used Solar cell manufacturing materials. In general, crystalline silicon cells are currently the mainstream of photovoltaic cells. They are mainly used in solar roof power stations, solar commercial power stations, and solar power stations. They are the most mature and most widely used solar photovoltaic products and occupy more than the share of the global photovoltaic market. 80%.

(b) Characteristics of thin film solar cells. The conversion rate of non-microcrystalline silicon thin-film batteries is low, and the technical difficulty of increasing the conversion rate is also greater. The raw materials of copper indium gallium selenide thin-film batteries are expensive, while the conversion rate of cadmium telluride thin-film batteries is high, but they are subject to material sources and safety. Limitations, large-scale industrialization also have limitations. At present, the conversion efficiency of thin-film batteries is within 10% on average, and the selling price is about 10 yuan/W. Although the unit price is lower than that of crystalline silicon batteries, the overall cost is still higher than that of crystalline silicon batteries due to the low conversion rate. Compared with crystalline silicon cell production lines, thin-film batteries have a higher one-time investment. Because they mainly rely on imported equipment, the investment of several hundred million yuan is 7-8 times that of crystalline silicon batteries, coupled with the simultaneous production of technical costs in the production process. The cost of equipment, transportation costs, and its overall cost do not have a clear advantage over crystalline silicon batteries. And because of the short life span and the large footprint, the speed of adoption has been affected.

(C) a correct view of the crystal silicon battery and thin film battery dispute. In 2005, the global supply of polysilicon was in short supply, and the selling price was continuously sizzling, reaching a maximum of US$500 kilograms, resulting in a high production cost of crystalline silicon batteries. Thin-film batteries developed rapidly under this background, and many domestic PV companies successively devoted themselves to In the investment boom of thin-film batteries, Suntech, Jiangxi LDK, and New Austrian all purchased thin-film battery equipment from abroad and established a thin-film battery production line. As the price of polysilicon continues to decline, the cost of crystalline silicon batteries has also dropped significantly. The cost advantages of thin-film batteries have been challenged. Many thin-film battery manufacturers have also suffered heavy orders. Many domestic photovoltaic companies are also planning to expand their thin-film battery production lines. As a result, there have been varying degrees of stranding and many projects have still not made substantial breakthroughs. The data shows that in 2009, the output of thin-film batteries in China accounted for only 2% of the total output of solar cells. The market share of thin-film batteries in the world is only 19%, and crystalline silicon cells still occupy absolute advantages. Experts from the Energy Research Institute of the National Development and Reform Commission believe that thin-film batteries do have future prospects, but it is difficult to compete with crystalline silicon batteries in the short-term. It is expected that by 2030, the market share of thin-film batteries is expected to rise to 30%, and the other 70% still needs Crystal silicon battery to support.