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Photovoltaic module introduction "Monocrystalline Silicon, N-type, Half-cell, imbricate, Heterojunction, PERC, TOPCon"

 

 

Photovoltaic modules, also known as solar panels, are the most important components in solar power generation systems. A complete photovoltaic module is composed of dozens of solar cells, junction boxes and frames. Since single solar cells cannot be used directly as power sources, if you want to use them as power sources, you must connect several single cells in series and parallel and tightly seal them into modules.

 

The principle of solar power generation, sunlight shines on the semiconductor p-n junction of the photovoltaic cell to form new hole-electron pairs. Under the action of the p-n junction electric field, holes flow from the p region to the n region, and electrons flow from the n region to the p region. When the circuit is connected, current is formed. Its function is to convert solar energy into electrical energy and send it to the battery for storage, or to drive the load to work.

 

Three types of solar cell technologies

 

1. Crystalline silicon solar cell technology, there is a difference between single crystal silicon and polycrystalline silicon. The advantage is that the photoelectric conversion rate is high, which can reach more than 21%. The disadvantage is that the price is relatively expensive. Crystalline silicon solar cell technology is the mainstream technology in the current market.

 

2. Thin-film solar cell technology has the advantages of less material consumption and lower price. The major disadvantage is that the photoelectric conversion rate is only half of that of crystalline silicon, but the conversion efficiency is only 6%-10%, so the market share has always been very low.

 

3. New solar cell technology has the advantages of high conversion rate and low cost. Perovskite photovoltaic cells are a new type of solar cell product that is expected to be mass-produced the fastest. The theoretical efficiency limit of single-junction perovskite cells can reach 33%, which is higher than that of crystalline silicon cells and thin-film cells. However, the biggest disadvantage of perovskite photovoltaic cells is that the efficiency attenuation is relatively serious. Before the efficiency attenuation technology is solved, it will not be used on a large scale for the time being.

 

Polycrystalline silicon photovoltaic modules and monocrystalline silicon solar modules

 

1. Polycrystalline silicon photovoltaic modules: photovoltaic modules processed from polycrystalline silicon wafers. Polycrystalline silicon is made of polycrystalline silicon block materials using ingot casting technology (square silicon ingots).

 

2. Monocrystalline silicon photovoltaic modules: photovoltaic modules processed from monocrystalline silicon wafers. Monocrystalline silicon is made from polycrystalline silicon block materials using a rod drawing process (round silicon rods).

 

P-type photovoltaic modules and N-type photovoltaic modules

 

1. P-type photovoltaic modules: photovoltaic modules assembled using P-type solar cells. P-type solar cells are silicon wafers into which the trivalent element "boron" is infiltrated during the cell doping process, and the element "gallium" can also be added. The conversion rate of P-type cells in mass production of photovoltaic modules in 2023 is about 21.1% to 21.5%.

 

2. N-type photovoltaic modules: photovoltaic modules assembled using N-type solar cells. N-type solar cells are silicon wafers into which the pentavalent element "phosphorus" is infiltrated during the cell doping process, and the element "arsenic" can also be added. The conversion rate of N-type cells in mass production of photovoltaic modules in 2023 is about 22.1% to 22.5%.

 

Types of photovoltaic module structure processes

 

1. Half-cell structure process: a cell is cut into two pieces and then assembled into a photovoltaic module.

 

2. imbricate structure process: Cut a cell into five to six long strips, and then use conductive glue to overlap the edges of multiple small cells to assemble into photovoltaic modules.

 

3. Flexible module process: Flexible modules are also called lightweight modules. Photovoltaic modules can be bent and are particularly suitable for installation on curved roofs. One solution is to use a flexible panel instead of a glass panel based on the imbricate photovoltaic module process. Another solution is to use thin-film batteries to make flexible photovoltaic modules.

 

Solar cell size classification

 

(I) Introduction to 182-size and 210-size cells

 

1. 182 photovoltaic module lineup manufacturers: photovoltaic modules with a single cell size of 182 (182mm*182mm).

 

2. 210 photovoltaic module lineup manufacturers: photovoltaic modules with a single cell size of 210 (210mm*210mm).

 

(II) Rectangular photovoltaic module size and cell introduction

 

1. Rectangular photovoltaic module size: On July 7, 2023, 9 domestic photovoltaic module manufacturers reached a consensus to unify the size of rectangular photovoltaic modules to 2382mm*1134mm.

 

2. Rectangular solar cell size: On August 8, 2023, 6 domestic photovoltaic module manufacturers reached a consensus to unify the size of rectangular solar cells to 182.2mm*191.6mm.