光伏组件的成本构成

1）核心部件——电池片：从功能来看，电池片是通过将硅片加工处理得到的可以将太阳的光能转化为电能的半导体薄片，决定了光伏系统的发电能力，原理是光生伏特效应和 PN 结。电池片的转换效率直接影响光伏系统的发电效率，电池片生产工艺的优良直接影响光伏系统使用寿命；从成本占比来看，电池片是光伏组件成本的核心，同时也是光伏组件降本的主要途径，根据华经产业研究院统计，2021 年电池片占组件成本的61.2%，同比-1.2pct，主要系受到上下游的双重压力影响导致电池片价格承压下行。

2）电气连接装置——焊带、接线盒：从功能来看，焊带分为用于串联电池片的互联焊带和用于连接电池串及接线盒的汇流焊带，用于收集电池片转化的电流，是组件中的核心电气连接部件，直接影响组件电流的收集效率和电池片的碎片率。接线盒能够将组件内产生的电流传输到外部线路，其结构中二极管的性能具备在组件故障时形成旁路通路保持正常工作（旁路二极管），以及低光照时防止电流回流（阻塞二极管）等作用；从成本占比来看，焊带环节多采用“原材料+加工费”定价模式，价格受原材料铜、锡价格波动较大，根据华经产业研究院统计，2021年焊带占组件成本的2.6%，同比-0.7pct；接线盒环节较为稳定，2021 占组件成本的2.6%，同比+0.1pct，成本变动较小。

3）封装材料——光伏玻璃、背板：从功能来看，光伏玻璃是能够利用太阳辐射发电并引出电流的特种玻璃，同时也是组件最外层的透光封装面板，主要起透光和保护作用，较传统玻璃具有含铁量低、透光率高、耐高温、耐氧化、耐腐蚀等优势，其质量直接影响组件发电效率和使用年限。背板是组件背部的封装材料，以有机高分子类材料为主，也有适用于双玻晶硅组件的无机物类材料（玻璃背板等）。背板能够保护光伏组件免受光、湿、热等外部环境的侵蚀，具备较高光反射率的背板也能提升组件整体的光电转换效率；从成本占比来看，根据华经产业研究院统计，受双玻组件渗透率提升影响，2021 年光伏玻璃占组件成本的7.1%，同比+1.0pct；2021年光伏背板的基础材料——PVDF 薄膜及其原材料氟树脂价格一路走高，背板价格也不断攀升，2021 年占组件成本的 5.2%，同比+2.1pct。

4）封装辅材——EVA 胶膜、铝边框：从功能来看，光伏胶膜具备优越的黏着力、耐久性和光学特性，主要将电池片与玻璃、背板粘接，起到保护电池片、隔绝空气的作用。由于粘接过程不可逆，所以胶膜的质量直接决定了组件的封装质量和使用寿命。铝边框作为组件最外层的封装结构，相较钢边框和橡胶件卡扣短边框具有更强的承载能力和耐腐蚀性，同时轻便性较好，完美契合了组件的特性需求，属于中短期内不可替代的刚需辅材；从成本占比来看，2021 年 EVA 市场受美国寒潮、光伏需求爆发等影响，价格屡创新高，根据华经产业研究院统计，2021 年EVA胶膜占组件成本比重为 8.4%，同比+1.1pct；铝边框环节 2021 年占组件成本的9.0%，同比-2.5pct，主要系大尺寸组件的边框单耗低于小尺寸组件，以及2021 年大尺寸组件渗透率提升所致。

1) Core component -- cell chip: From the perspective of function, cell chip is a semiconductor chip that can convert the solar light energy into electric energy through the processing of silicon chip, which determines the power generation capacity of photovoltaic system. The principle is the photogenerated volt effect and PN junction.   The conversion efficiency of the cell directly affects the power generation efficiency of the photovoltaic system, and the excellent production technology of the cell directly affects the service life of the photovoltaic system.  From the perspective of the cost ratio, the battery is the core of the cost of photovoltaic modules, but also the main way to reduce the cost of photovoltaic modules, according to the statistics of China Economic Industry Research Institute, in 2021, the battery accounted for 61.2% of the cost of modules, compared with -1.2PCT, mainly affected by the dual pressure of upstream and downstream resulting in the downward pressure on the price of battery panels.  

2) electrical connection device, welding, junction box: from a functional perspective, welding zone is divided into interconnected welding for tandem solar cell and used to connect the battery string and junction box of the confluence weld zone, used to collect current of cell transformation, is the core component in the electrical connection parts, directly affect the collection of component current efficiency and cell debris rate.   The junction box can transmit the current generated in the component to the external circuit. The performance of the diode in its structure has the function of forming a bypass path to maintain the normal work when the component fails (bypass diode), and prevent the current backflow (blocking diode) when the light is low.  From the perspective of cost ratio, the "raw material + processing fee" pricing mode is mostly adopted in the welding belt link, and the price fluctuates greatly depending on the price of copper and tin. According to the statistics of China Economic Industry Research Institute, the welding belt accounted for 2.6% of the component cost in 2021, which was -0.7PCt compared with the previous year.  The junction box link is relatively stable, accounting for 2.6% of the component cost in 2021, which is +0.1 PCT compared with the previous year, and the cost changes are small.  

3) Packaging materials -- photovoltaic glass, backplane:  From a functional perspective, photovoltaic glass is able to take advantage of solar radiation power and lead to the current special glass, but also the most outer layer of the pervious to light components encapsulation panel, mainly from pervious to light and protection, the traditional glass has a low iron content, high light transmittance, high temperature resistant, resistant to oxidation, corrosion resistance and other advantages, its quality directly affects the component power generation efficiency and use fixed number of year.  The backplane is the packaging material for the back of the component, mainly organic polymer materials, but also inorganic materials (glass backplane, etc.) suitable for double glassy silicon components.  The backplane can protect the PV module from the erosion of external environment such as light, humidity and heat. The backplane with high optical reflectance can also improve the overall photoelectric conversion efficiency of the module.   From the perspective of cost proportion, according to the statistics of China Economic Industry Research Institute, influenced by the increase of double-glass module penetration, photovoltaic glass accounted for 7.1% of the module cost in 2021, which was +1.0 PCT compared with the previous year;  In 2021, the basic material of PV backplane -- PVDF film and its raw material fluorine resin price went up all the way, and the backplane price also kept climbing, accounting for 5.2% of the component cost in 2021, +2.1 PCT year-on-year.  

4) Encapsulation auxiliary materials - EVA film, aluminum frame: From the perspective of function, the photovoltaic film has excellent adhesion, durability and optical characteristics, mainly bonding the battery sheet with glass and backplane, to protect the battery sheet and isolate the air.   Since the bonding process is irreversible, the quality of the film directly determines the packaging quality and service life of the component.  As the outermost packaging structure of the component, the aluminum frame has stronger bearing capacity and corrosion resistance than the steel frame and the short frame of the rubber fastener. At the same time, it has good portability and perfectly meets the characteristics of the component. It is an irreplaceable rigid auxiliary material in the short and medium term.  From the perspective of cost ratio, the EVA market in 2021 was affected by the cold wave in the United States and the explosion of photovoltaic demand, and the price repeatedly set new highs. According to the statistics of China Economic Industry Research Institute, the proportion of EVA film in the component cost in 2021 was 8.4%, +1.1 PCT.  Aluminum frame segment accounted for 9.0% of component cost in 2021, -2.5PCT year-on-year, mainly due to the lower frame consumption of large-size components than small-size components, and the increased penetration of large-size components in 2021.