A Comprehensive Guide to Photovoltaics: System Components and the Complete PV Module Manufacturing Process

Preface 

With the rapid development of the new-energy industry, photovoltaic (PV) technology—as a clean, efficient, and renewable energy source—has been widely deployed in industrial applications, residential settings, and power plants. As the core power-generating unit of a PV system, the composition and manufacturing process of PV modules directly determine their conversion efficiency and service life. The membrane industry is deeply intertwined with the PV sector, with encapsulant films and protective films representing key application areas for membrane materials. Understanding the structure of PV systems and the module manufacturing process can help industry players better seize cross-sector opportunities. This article breaks down the complete architecture of a PV system, the core components of a PV module, and the end-to-end manufacturing workflow—from silicon ingots to finished modules—into concise sections, making it suitable for both membrane-industry professionals and newcomers to the PV field. 

I. Complete Composition of a Photovoltaic System: Multi-Component Coordination, Going Beyond Just PV Modules 

A functioning photovoltaic power generation system consists of “ Power Generation Core + Auxiliary supporting facilities ” Form a complete system in which each component performs its designated function and is indispensable, categorized by function as: 4 Major categories all adhere to industry standards: 

(1) Core Power-Generation Component: Photovoltaic Panels (Photovoltaic Modules) 

photovoltaic system's “ heart ” , responsible for converting solar energy into electrical energy, is the most cost-intensive component in the system ( 50%-60% ). The photovoltaic panels seen outdoors are of this type: their core consists of solar cells, which are protected by encapsulating materials to ensure long-term stability under outdoor conditions. 

(2) Power Conversion Component: Inverter 

Photovoltaic panels generate direct current, while most everyday electricity use is alternating current. The core function of an inverter is to convert between AC and DC, while also stabilizing voltage, ensuring power quality, and preventing equipment damage. Inverters are categorized into centralized types (for large-scale power plants) and string types (for rooftop PV systems), which are integral to the utilization of electrical energy. “ Transfer Hub ”。

(3) Supporting and Fixing Components: Brackets and Foundations 

These structures are used to secure photovoltaic panels, ensuring they are oriented at the optimal angle—aligned with the local latitude—to maximize solar irradiance while withstanding outdoor environmental stresses such as wind, rain, and snow accumulation. The mounting racks are typically made of corrosion-resistant aluminum alloy, and the foundations vary depending on the installation site, including concrete footings or weighted blocks. The primary design requirements are structural stability and resistance to aging. 

(4) Connection and Transmission Components: Cables and Junction Boxes 

1. Cables: Used to connect various devices for power transmission, they must be resistant to high and low temperatures, UV radiation, and water and moisture to prevent outdoor aging and electrical leakage. 

2. Junction box: Mounted on the back of the solar panel to collect and output the current from the solar cells; equipped with built-in diodes to prevent reverse current flow and mitigate hot-spot effects; with a protection rating of no less than IP65。

Supplement A complete photovoltaic system also includes a distribution panel and a grounding system; the former distributes electrical power and protects the circuit, while the latter provides lightning protection and leakage protection, ensuring the safe operation of the system. 

II. Core Components of Photovoltaic Panels: 6 Major components lay the foundation for power generation. 

Photovoltaic panels are hermetically sealed assemblies, which from the outside in are divided into 6 Major critical components, comply with “ Light transmission, encapsulation, protection, and conductivity ” Principle: Each component works in concert to ensure power generation efficiency and 25 A service life of more than one year, with the membrane material serving as the core supporting component: 

(1) Surface Light-Transmitting Protective Layer: Low-Iron Ultra-Clear Tempered Glass 

The outermost layer of the circuit board primarily serves to allow light transmission, resist impact, and provide corrosion protection. Iron content ≤0.015% , light transmittance ≥91% , with an anti-reflective coating on the surface to reduce light loss; the edges are tempered for enhanced durability. 10mm Steel ball 1 Withstands high-altitude drop impacts and various harsh outdoor environments. 

(2) Encapsulation Adhesive Layer: EVA/POE Adhesive film (a core application in the film industry) 

Located between the glass and the solar cells, and between the solar cells and the backsheet, with a thickness of 0.45-0.6mm , is of the photovoltaic panel “ Binder + Insulating protective layer ” , which also represents the core integration point between the membrane industry and photovoltaics. Its key functions are: tightly bonding the layers to prevent delamination; providing insulating protection for the solar cells; and maintaining high light transmittance. ≥90% Does not affect photoelectric conversion; aging-resistant and yellowing-resistant, meeting 25 Outdoor usage requirements for the year. The mainstream type is POE Encapsulant film (the first choice for high-end modules, resistant to PID Excellent performance), EVA Adhesive film (traditional mainstream, cost-effective). 

(3) Core Power Generation Layer: Solar Cells 

of photovoltaic panels “ Soul ” , the only component that achieves photoelectric conversion, accounts for the cost of the solar panel. 60% Above, the mainstream is monocrystalline silicon ( P type /N Model, mass-production efficiency 23%–26% ）、polycrystalline silicon (efficiency 18%–21% ). The voltage of a single solar cell is approximately 0.5V , requires series and parallel connection ( 36/60/72 (Section) Adjust the output voltage and current; the thickness is only 150–200 μm , with a fragile texture that requires encapsulation for protection. 

(4) Back Protection Layer: Photovoltaic Backsheet 

The innermost layer of the circuit board primarily serves to provide moisture resistance, oxidation protection, and UV resistance, while also preventing the ingress of water vapor and dust. The mainstream types are TPT 、 Thermoplastic elastomer etc., among which TPT The backsheet offers optimal weather resistance, and bifacial solar modules utilize a bifacial backsheet to enable auxiliary power generation from the rear side. 

(5) Frame Protection Layer: Aluminum Alloy Frame 

The anodized aluminum alloy surrounding the circuit board serves to secure the overall structure, protect the edges, and facilitate installation. Cross-section U Edge-sealed with silicone for enhanced waterproofing; pre-drilled mounting holes for bracket alignment; anodized finish. ≥10μm , resistant to corrosion in various environments such as coastal and plateau regions. 

(6) Conductive Output Components: Junction Box and Lead Wires 

1. Junction box: built-in bypass / Blocking diode to prevent hot-spot effects and current backflow; flame-retardant enclosure with protection rating IP65 The above; 

2. Lead-in cable: Tinned copper conductors are coated with a weather-resistant insulating film, connecting the junction box to the system cable and transmitting electrical power. 

III. The Complete Manufacturing Process of Photovoltaic Panels: From Silicon Feedstock to Finished Products, 4 Major Core Phase 

The manufacturing of photovoltaic panels is a highly automated and precision-intensive process, with the core divided into “ Silicon material purification → Silicon wafer manufacturing → Solar cell manufacturing → Component encapsulation ” The process is divided into four major stages, each with stringent process standards; any deviation can compromise the performance of the circuit board, and the entire process complies with environmental protection requirements. 

(1) Phase One: Silicon Material Purification (Raw Material Source) 

The core raw material for photovoltaic panels is 6N Level ( 99.9999% ) High-purity silicon, refined from quartz sand (silicon dioxide): 

1. Raw material reduction: quartz sand and carbon in 1500–2000°C Smelted in an electric arc furnace, producing 98% Metallurgical-grade silicon of high purity; 

2. Chemical purification: The modified Siemens process is employed to convert metallurgical-grade silicon into trichlorosilane gas, which is then distilled and purified before being reduced via chemical vapor deposition to 6N High-purity polycrystalline silicon can be directly produced using emerging granular silicon technology, reducing costs. 20%。

(2) Phase 2: Silicon Wafer Manufacturing (Solar Cell Substrate) 

High-purity polysilicon is processed into ultra-thin silicon wafers through a fully physical manufacturing process: 

1. Silicon ingot / Silicon ingot production: After polysilicon is melted, it can be processed into single-crystal silicon ingots via the Czochralski method (high efficiency) or into polycrystalline silicon ingots via the casting method (cost-effective). 

2. Slicing: Diamond wire saws silicon ingots. / Silicon ingot cutting is 150–180 μm Thick silicon wafers, mainstream sizes 182mm、210mm；

3. Texturing: Cleaning impurities from silicon wafers and using chemical etchants to create micrometer-scale structures. “ Pyramid ” Suede, reducing the light reflectance from 35% Decrease to 10% , to enhance light absorption. 

(3) Phase Three: Solar Cell Manufacturing (Conversion into Power-Generating Units) 

The core of fabricating silicon wafers into photosensitive devices is to form PN Conclusion: extremely high precision is required: 

1. Doping and junction formation: 850-900℃ In the diffusion furnace, phosphorus and boron are diffused into the silicon wafers to form PN This lays the foundation for photoelectric conversion; 

2. Edge etching: Plasma etching is used to remove the edge phosphosilicate glass to prevent short circuits; 

3. Anti-reflective coating: PECVD Silicon nitride thin-film coating technology reduces light reflection and passivates surface defects; 

4. Screen-printed electrodes: silver paste is used to print the front and back grid circuits, while aluminum paste is used to form the rear aluminum back surface field. 800-900℃ Ohmic contact is formed via high-temperature sintering; 

5. Testing and sorting: The efficiency, voltage, and other parameters of solar cells are measured, and cells with consistent performance are sorted; non-conforming units are collected for reprocessing. 

(4) Phase Four: Module Packaging (Production of Finished Solar Panels, Core Application of Membrane Materials) 

Individual solar cells are fragile and have low voltage; after encapsulation, they form the finished product, at which stage... EVA/POE Core application stages of adhesive film: 

1. String soldering of solar cells: An automated soldering machine uses tinned copper ribbon to connect the solar cells in series, forming a cell string. 

2. Lamination: according to “ Tempered glass →EVA/POE Adhesive film → Battery string →EVA/POE Adhesive film → Back panel ” Stacked precisely in sequence; 

3. Lamination Packaging: in a Vacuum Laminator 140-150℃ Apply heat and pressure to melt and cure the adhesive film, firmly bonding the layers together while expelling trapped air. 

4. Trimming and cleaning: remove excess adhesive flash and clean the surface of the circuit board; 

5. Frame and junction box: Install an aluminum alloy frame and seal it with silicone; mount the junction box on the back to connect the battery strings. 

6. Finished-product testing: Conduct tests for power, high-voltage insulation, waterproofing, and other parameters to ensure compliance with the “Normative Conditions for the Photovoltaic Manufacturing Industry ( 2024 Only products that meet the “Annual Standard” may leave the factory. 

IV. Correcting Common Misconceptions: Avoiding Industry-Wide Misunderstandings 

Based on the cognitive characteristics of professionals in the membrane industry, this document systematically corrects common misconceptions related to photovoltaics to ensure that the content is free from bias: 

1. Misconception 1 : Photovoltaic panel = Solar cells? → Incorrect. Solar cells are only the core component; they must be encapsulated with glass, EVA film, and other materials before they can be used as outdoor photovoltaic panels. 

2. Misconception 2 : Is higher silicon material purity always better? → Error: silicon material for photovoltaics 6N A moderate level is sufficient; excessively high purity will significantly increase costs and offer no practical benefit. 

3. Misconception 3 : Does photovoltaic panel manufacturing cause pollution? → Incorrect; the entire process is primarily focused on metallurgy and physical processing, with a small amount. VOCs Can be treated using environmental protection equipment and complies with national standards; 

4. Misconception 4： EVA Has the adhesive film been completely replaced? → Error, POE Adhesive film is the top choice for high-end applications. EVA Encapsulant films offer excellent cost performance and remain widely used in mid- to low-end solar modules. 

Conclusion 

A photovoltaic system is a complete, multi-component, synergistic ecosystem. The manufacturing of photovoltaic panels involves four major stages, from silicon ingots to finished products, with stringent process standards at every step—demonstrating both the precision of the new-energy industry and highlighting EVA/POE The pivotal role of film materials, such as encapsulant films, in the photovoltaic industry. For professionals in the membrane industry, gaining a solid understanding of photovoltaics not only broadens their industry perspective but also enables them to accurately identify the points of intersection between membrane materials and the PV sector, thereby seizing new opportunities for industry development. 

Currently, N Laminated batteries, large-format modules, and high-efficiency encapsulant films have become the industry standard in the photovoltaic sector. As a result, the power conversion efficiency of PV modules continues to rise while costs keep falling, leading to an ever-expanding range of applications. Looking ahead, the integration of film materials with the PV industry will grow even closer; upgrades in the weather resistance of encapsulant films and innovative applications of protective films will both provide critical support for the high-quality development of the PV sector. It is our hope that this article will help professionals in the film industry gain a clear understanding of PV technology, serving as a valuable reference for future cross-sector collaborations and business expansion.