Driven by the goals of carbon peaking and carbon neutrality, the photovoltaic (PV) industry has emerged as a core engine of the global new energy development. Spanning from silicon material purification to module encapsulation, PV manufacturing is a highly sophisticated production line with stringent requirements for precision, cleanliness and stability. As the fourth major energy source permeating the entire industrial chain, the compressed air system is the lifeline ensuring high yield rates and production continuity of PV products. Air compressors, especially oil-free air compressors, are deeply integrated into every core link of the PV industrial chain by virtue of their stable, clean and efficient air supply characteristics, providing an indispensable power support for each process of photoelectric conversion.

Production Process

1. Silicon Wafer Manufacturing: Pure Air Source Lays the Foundation for Optoelectronics

Silicon wafers are the core substrate of PV cells, and their surface quality directly determines the photoelectric conversion efficiency of the cells. This process has extremely high requirements for the dryness and cleanliness of compressed air—any tiny impurities, oil stains or moisture may cause scratching and contamination of silicon wafers, leading to an increase in defective rates.

Silicon Ingot/Block Processing: In the forming and processing of monocrystalline/polycrystalline silicon ingots, air compressors provide stable power for pneumatic robotic arms and crystal clamping devices to achieve precise handling and positioning of silicon materials. Meanwhile, high-pressure clean air is used for purging and cleaning the surface of silicon ingots to remove cutting debris and dust.

Silicon Wafer Cutting and Cleaning: The pneumatic tension control and pneumatic nozzle systems of multi-wire saws all rely on stable compressed air. In the crucial texturing and cleaning processes, oil-free compressed air serves as a process auxiliary gas, cooperating with chemical solutions to etch, clean and dry the silicon wafer surface, ensuring the formation of a uniform suede structure on the silicon wafer surface and laying a solid foundation for high-efficiency light absorption in subsequent processes.

Quality Assurance: Class 0 oil-free air compressors must be selected for this process to ensure the oil content of compressed air is ≤0.01ppm, eliminating the risk of oil contamination from the source and protecting precious silicon wafer materials.

2. Solar Cell Manufacturing: Precision Control Improves Photoelectric Efficiency

Solar cell manufacturing is the technological core of the PV industrial chain, involving a series of sophisticated processes such as diffusion, coating, printing and sintering. In this process, compressed air not only acts as a power source but also a process gas directly participating in reactions, and its quality directly affects the conversion efficiency and yield rate of solar cells.

Diffusion and PECVD: In phosphorus diffusion and boron diffusion processes, compressed air drives pneumatic valves and instruments to accurately control the flow and on-off of process gases (e.g., POCl3). In the Plasma Enhanced Chemical Vapor Deposition (PECVD) process, clean and dry air is used for gas circuit control and cavity purging in the deposition process of silicon nitride anti-reflection films, ensuring uniform and dense film layers.

Screen Printing and Sintering: This is the largest air-consuming process in solar cell manufacturing. Air compressors provide power for the pneumatic platforms and scraper pressure control systems of high-precision printing machines to ensure the accurate printing of silver-aluminum paste on the silicon wafer surface. Meanwhile, high-pressure air is used for online cleaning and drying of printing screens, as well as workpiece conveying and cooling before and after the sintering furnace.

Core Requirements: The production requires 24/7 continuous operation, demanding air compressors with extremely high stability (pressure fluctuation ≤±0.1bar) and excellent energy efficiency. Permanent magnet variable frequency oil-free screw air compressors are the ideal choice for this process, which can be dynamically adjusted according to real-time air consumption, effectively reducing the energy consumption of air compressors that accounts for 15%-25% of the total production energy consumption.

3. PV Module Encapsulation: Stability and Reliability Guard Product Lifespan

The module process is the process of assembling solar cells into the final PV modules, with the core goal of achieving efficient, stable and long-life encapsulation. Compressed air mainly provides pneumatic power and precision control to ensure encapsulation quality and production efficiency.

Solar Cell String Welding and Layout: Pneumatic suction nozzles use vacuum (driven by air compressors via vacuum generators) to accurately pick up and handle fragile solar cells for string welding and layout, avoiding microcracks caused by mechanical contact throughout the process.

Lamination and Encapsulation: In laminators, clean compressed air is used to provide uniform pneumatic pressure and heating/cooling control, ensuring the perfect bonding of EVA film, glass and backsheet, exhausting internal air bubbles, and forming a sealed and firm integral structure. Any oil stains may cause lamination defects, peeling or accelerated aging, making oil-free air supply crucial.

Frame Assembly and Testing: Pneumatic tools are used for automatic gluing, riveting and fastening of aluminum alloy frames. High-pressure air is used for air tightness testing and surface cleaning of finished modules to ensure the ex-factory quality of the final products.

4. PV Power Plant Construction and Operation & Maintenance: All-round Assistant Ensures Long-term Power Generation

The value of the PV industrial chain is ultimately realized at the power plant end. Air compressors are also indispensable equipment in the construction and long-term operation & maintenance of PV power plants.

Power Plant Construction: In the pile foundation construction of PV supports, large mobile air compressors provide impact power for down-the-hole drills to efficiently complete drilling operations in complex terrains such as mountainous areas and Gobi deserts.

Daily Operation & Maintenance: Power plant operation and maintenance personnel use portable air compressors to drive pneumatic wrenches for support fastening, equipment maintenance and other work. More importantly, high-pressure air generated by air compressors is used for non-contact purging and cleaning of PV panels, efficiently removing dust, sand and bird droppings on the surface to restore and stabilize the power generation efficiency of PV systems.

5. Core Selection Criteria for Air Compressors in the PV Industry

In view of the special production environment of the PV industry, the selection of air compressors must meet three core standards:

Ultimate Cleanliness, Oil-free Assurance: Prioritize the selection of oil-free screw air compressors (dry oil-free or water-lubricated oil-free) with ISO 8573-1 Class 0 oil-free certification to completely eliminate the contamination of products by oil, dust and water.

High Efficiency and Energy Saving, Green Symbiosis: Select first-class energy efficiency and permanent magnet variable frequency models to adapt to the load fluctuation characteristics of PV production lines and significantly reduce electricity costs. Equipped with a waste heat recovery system, the heat energy generated by compression can be recycled for process heating to further improve comprehensive energy efficiency.

Stability and Reliability, Continuous Operation: Shutdowns of PV production lines result in huge losses, requiring air compressors to have high reliability and intelligent joint control capabilities. Cooperate with complete post-processing equipment such as drying and filtration systems to ensure uninterrupted and high-quality air supply throughout the year.

From silicon material purification to power generation at power plants, air compressors deeply empower every link of the PV industrial chain with clean, stable and efficient compressed air, serving as an invisible cornerstone for ensuring high quality and high conversion rate of PV products. As the PV industry rapidly evolves towards high-efficiency, large-size and N-type technologies, the requirements for compressed air systems are becoming increasingly stringent. Choosing a professionally adapted oil-free air compressor solution is not only a necessary condition for ensuring production yield but also a key strategic investment for PV enterprises to practice green manufacturing, reduce operating costs and enhance core competitiveness.