The smallest effective power generation unit in the PV industry and the equipment that undertakes PV conversion in PV power plants are called PV modules.

　　PV modules are also called or solar panels, which are made of multiple cells connected in series and parallel, packaged and combined with other auxiliary materials. The manufacturing process mainly includes two steps: cell interconnection and lamination:

　　(1) At present, the standard number of PV modules is 60 or 72 cells, corresponding to 10 or 12 copper wires as bus bars to connect them, and 6 groups are interconnected to form a PV module. The series-parallel connection of the cells determines the electrical performance of the module.

　　(2) After the cells are interconnected, they generally need to be laminated together in the order of tempered glass, adhesive film, cell, and backplane from bottom to top, and protected by aluminum frame and silicone sealing edge. In this way, the service life can be greatly increased, and the environmental resistance and mechanical performance can be significantly improved.

　　Currently, there are two main development trends for PV cells, namely, bifacial modules and half-chip packaging.

　　(1) Double-sided modules refer to PV modules that use double-sided cells, which are characterized by the ability to generate electricity on both the front and back sides. When sunlight shines, part of the light will be reflected by the surrounding environment to the back of the module, and the double-sided module has the ability to collect this part of the light energy, thereby increasing the power generation.

　　Obviously, compared with the traditional single-sided design, the double-sided battery has better power generation, but the production process is also more complicated and the cost is higher.

　　(2) Half-chip packaging is the current mainstream packaging mode. The current generated by the PV cell during the power generation process is related to the cell area, so compared to the whole cell, the current through the main grid line in the half-cell package cell is only about 1/2. When the half-cell packaged batteries are connected in series, the resistance of a single positive and negative loop is unchanged, and the power loss of a single loop is reduced to 1/4 of the original, thereby reducing the overall power loss of the module, and also reducing the negative impact from heating of the module on the power generation capacity.

　　Under normal circumstances, during the packaging process of battery modules, a phenomenon called CTM (Cell-to-Module Loss) will occur, that is, the total power generation of the modules is less than the sum of the total power of the cells. Reducing the CTM loss is one of the component development ideas. Half-chip packaging performs well at this point, and has the characteristics of relatively simple production process and low production cost, so it is widely used.

　　As of 2020, the market share of half-chip packaging has reached 71%, an increase of 50% year-on-year, and it has surpassed full-chip packaging to become the absolute mainstream of the market.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect replacement for lead-acid batteries, and they are the first choice for grid-connected peak shaving, off-grid energy storage, PV energy storage, UPS, data center and other industries.

　　Solar power generation system with lithium battery energy storage system is a very promising clean energy.