The Role of Copper Expanded Mesh in Power Generation Blades

Copper expanded mesh used in power generation blades (usually referring to wind turbine blades or blade-like structures in solar photovoltaic modules) plays a core role in ensuring electrical conductivity, enhancing structural stability, and optimizing power generation efficiency. Its functions need to be analyzed in detail based on the type of power generation equipment (wind power/photovoltaic). The following is a scenario-specific interpretation:

1. Wind Turbine Blades: Core Roles of Copper Expanded Mesh – Lightning Protection and Structural Monitoring

Wind turbine blades (mostly made of glass fiber/carbon fiber composite materials, with a length of up to tens of meters) are components prone to lightning strikes at high altitudes. In this scenario, copper expanded mesh mainly undertakes the dual functions of “lightning protection” and “health monitoring”. The specific roles are broken down as follows:

1.1 Lightning Strike Protection: Building a “Conductive Path” Inside the Blade to Avoid Lightning Damage

1.1.1 Replacing the Local Protection of Traditional Metal Lightning Rods

Traditional blade lightning protection relies on the metal lightning arrester at the blade tip. However, the main body of the blade is made of insulating composite materials. When a lightning strike occurs, the current is likely to form a “step voltage” inside, which may break down the blade structure or burn the internal circuit. The copper expanded mesh (usually a fine copper woven mesh, attached to the inner wall of the blade or embedded in the composite material layer) can form a continuous conductive network inside the blade. It evenly conducts the lightning current received by the blade tip arrester to the grounding system at the root of the blade, avoiding current concentration that may break down the blade. At the same time, it protects internal sensors (such as strain sensors and temperature sensors) from lightning damage.

1.1.2 Reducing the Risk of Lightning-Induced Sparks

Copper has excellent electrical conductivity (with a resistivity of only 1.72×10⁻⁸Ω・m, much lower than that of aluminum and iron). It can quickly conduct lightning current, reduce high-temperature sparks generated by the current staying inside the blade, avoid igniting blade composite materials (some resin-based composite materials are flammable), and reduce the safety hazard of blade burning.

1.2 Structural Health Monitoring: Serving as a “Sensing Electrode” or “Signal Transmission Carrier”

1.2.1 Assisting in Signal Transmission of Built-in Sensors

Modern wind turbine blades need to monitor their own deformation, vibration, temperature, and other parameters in real time to determine whether there are cracks and fatigue damages. A large number of micro-sensors are implanted inside the blades. The copper expanded mesh can be used as the “signal transmission line” of the sensors. The low-resistance characteristic of the copper mesh reduces the attenuation of monitoring signals during long-distance transmission, ensuring that the monitoring system at the root of the blade can accurately receive health data of the blade tip and blade body. At the same time, the mesh structure of the copper mesh can form a “distributed monitoring network” with the sensors, covering the entire area of the blade and avoiding monitoring blind spots.

1.2.2 Enhancing the Antistatic Ability of Composite Materials

When the blade rotates at high speed, it rubs against the air to generate static electricity. If too much static electricity accumulates, it may interfere with internal sensor signals or break down electronic components. The conductive property of the copper expanded mesh can conduct static electricity to the grounding system in real time, maintaining the electrostatic balance inside the blade and ensuring the stable operation of the monitoring system and control circuit.

2. Solar Photovoltaic Modules (Blade-like Structures): Core Roles of Copper Expanded Mesh – Conductivity and Optimization of Power Generation Efficiency

In some solar photovoltaic equipment (such as flexible photovoltaic panels and “blade-like” power generation units of photovoltaic tiles), copper expanded mesh is mainly used to replace or assist traditional silver paste electrodes, improving conductivity efficiency and structural durability. The specific roles are as follows:

2.1 Improving Current Collection and Transmission Efficiency

2.1.1 A “Low-Cost Conductive Solution” Replacing Traditional Silver Paste

The core of photovoltaic modules is the crystalline silicon cell. Electrodes are needed to collect the photogenerated current generated by the cell. Traditional electrodes mostly use silver paste (which has good conductivity but is extremely expensive). The copper expanded mesh (with conductivity close to that of silver and a cost of only about 1/50 of that of silver) can cover the surface of the cell through a “grid structure” to form an efficient current collection network. The grid gaps of the copper mesh allow light to penetrate normally (without blocking the light-receiving area of the cell), and at the same time, the grid lines can quickly collect the current scattered in various parts of the cell, reducing the “series resistance loss” during current transmission and improving the overall power generation efficiency of the photovoltaic module.

2.1.2 Adapting to the Deformation Requirements of Flexible Photovoltaic Modules

Flexible photovoltaic panels (such as those used in curved roofs and portable equipment) need to have bendable characteristics. Traditional silver paste electrodes (which are brittle and easy to break when bent) cannot be adapted. However, the copper mesh has good flexibility and ductility, which can bend synchronously with the flexible cell. After bending, it still maintains stable conductivity, avoiding power generation failure caused by electrode breakage.

2.2 Enhancing the Structural Durability of Photovoltaic Modules

2.2.1 Resisting Environmental Corrosion and Mechanical Damage

Photovoltaic modules are exposed to the outdoors for a long time (exposed to wind, rain, high temperature, and high humidity). Traditional silver paste electrodes are easily corroded by water vapor and salt (in coastal areas), resulting in a decrease in conductivity. The copper mesh can further improve its corrosion resistance through surface plating (such as tin plating and nickel plating). At the same time, the mesh structure of the copper mesh can disperse the stress of external mechanical impacts (such as hail and sand impact), avoiding the cell from breaking due to excessive local stress and prolonging the service life of the photovoltaic module.

2.2.2 Assisting in Heat Dissipation and Reducing Temperature Loss

Photovoltaic modules generate heat due to light absorption during operation. Excessively high temperatures will lead to “temperature coefficient loss” (the power generation efficiency of crystalline silicon cells decreases by about 0.4% – 0.5% for every 1℃ increase in temperature). Copper has excellent thermal conductivity (with a thermal conductivity of 401W/(m・K), much higher than that of silver paste). The copper expanded mesh can be used as a “heat dissipation channel” to quickly conduct the heat generated by the cell to the surface of the module, and dissipate heat through air convection, reducing the operating temperature of the module and reducing the efficiency loss caused by temperature loss.

3. Core Reasons for Choosing “Copper Material” for Copper Expanded Mesh: Adapting to the Performance Requirements of Power Generation Blades

Power generation blades have strict performance requirements for copper expanded mesh, and the inherent characteristics of copper perfectly meet these requirements. The specific advantages are shown in the following table:

In conclusion, the copper expanded mesh in power generation blades is not a “universal component”, but plays a targeted role according to the type of equipment (wind power/photovoltaic). In wind turbine blades, it focuses on “lightning protection + health monitoring” to ensure the safe operation of the equipment; in photovoltaic modules, it focuses on “high-efficiency conductivity + structural durability” to improve power generation efficiency and service life. The essence of its functions revolves around the three core goals of “ensuring the safety, stability, and high efficiency of power generation equipment”, and the characteristics of copper material are the key support for realizing these functions.