Solar cell modules are also called solar photovoltaic modules, usually also referred to as battery modules or photovoltaic modules for short, and can also be called “Solar Module” or “PV Module”. The battery module is a product in which multiple single solar cells are connected in series and parallel as required, and packaged through special packaging materials and special production processes.
Why can’t single solar cells be directly used in photovoltaic power generation systems? This is because: ①The single solar cell has poor mechanical strength, with a thickness of only about 200μm, which is thin and fragile; ②The solar cell is easy to corrode. If directly exposed to the atmosphere, the conversion efficiency of the battery will be affected by factors such as humidity, dust, acid and alkali substances, and oxygen in the air. The electrodes of the battery will also oxidize, rust and fall off, and even cause the battery to fail; ③The output voltage, current and power of the single solar cell are very small, and the working voltage is only about 0.5V.
Due to the limitation of the size of the silicon chip, the maximum output power of the single cell is only about 4W, which is far from meeting the needs of the practical application of photovoltaic power generation.
At present, the solar cell components used in solar photovoltaic power generation systems are mainly crystalline silicon materials (including monocrystalline silicon and polycrystalline silicon). Therefore, this article will mainly introduce the principle, structure and manufacturing process of crystalline silicon solar cell modules, the combination, configuration and connection of solar photovoltaic arrays, and the design and selection of cell modules.
This article will first introduce the basic requirements and classification of battery components.
1. Basic requirements for battery modules
The battery components must meet the following requirements in the application:
① It can provide sufficient mechanical strength to enable the battery assembly to withstand the stress caused by impact, vibration, etc. during transportation, installation and use, and to withstand the impact of hail;
②It has good airtightness, can be windproof and waterproof, and can isolate the corrosion of the battery under atmospheric conditions;
③Has good electrical insulation performance;
④Strong anti-ultraviolet radiation ability;
⑤The working voltage and output power can be designed according to different requirements, and a variety of wiring methods can be provided to meet the requirements of different voltage, current, power and other output;
⑥The efficiency loss caused by the combination of cell series and parallel is small;
⑦Reliable connection between cells;
⑧Long working life, requiring battery components to be used for more than 25 years under natural conditions;
⑨As long as the aforementioned conditions are met, the packaging cost should be as low as possible.
2. Classification of battery modules
There are many types of battery components, which can be divided into crystalline silicon (single and polycrystalline silicon) battery components, amorphous silicon thin film battery components, and gallium arsenide battery components according to different types of solar cells; According to the different packaging materials and processes, it can be divided into epoxy resin encapsulated battery boards and laminated encapsulated battery components; According to different uses, it can be divided into ordinary battery components and building materials battery components. Building materials battery components are further divided into double glass battery components, hollow glass battery components, and double-sided power generation battery components made of double-sided power generation cells. Since the application of battery modules made with crystalline silicon cells accounts for more than 85% of the market share, this article mainly introduces various battery modules made with crystalline silicon cells.