Will PV Cables Become Brittle in Low-Temperature Environments? Complete Analysis of Answers and Solutions

In the construction of photovoltaic (PV) power plants, climate adaptability is one of the key considerations for cable selection. In winter, the low temperature in high-latitude areas and plateau regions in northern China can reach -30℃ to -40℃, and even lower in some extremely cold areas. Faced with extreme low-temperature environments, many constructors and owners will have questions: Will PV cables become brittle in low-temperature environments? In fact, ordinary cables are indeed at risk of becoming brittle at low temperatures, but PV-specific cables designed with special materials and processes can effectively resist the impact of low temperatures. This article will deeply analyze the core causes of low-temperature brittleness of PV cables, clarify the key factors affecting brittleness, and provide scientific selection and use suggestions to protect the construction of PV power plants in cold regions.

I. Core Answer: Ordinary Cables Are Prone to Brittleness, PV-Specific Cables Can Resist Cold
Whether PV cables become brittle in low-temperature environments depends on the material and process of the cable insulation layer and sheath. The insulation material of ordinary cables (such as conventional PVC cables) will experience decreased molecular chain activity and reduced flexibility at low temperatures. When the temperature drops below its brittle temperature, it will become stiff and fragile, and cracks or even breaks may occur when subjected to slight external forces (such as laying bending, collision, wind and snow impact), which is the "low-temperature brittleness" phenomenon
PV-specific cables (such as those complying with IEC 60228, GB/T 12706.1 and other standards) adopt low-temperature resistant special materials (such as cross-linked polyethylene XLPE, low-temperature resistant PVC, fluoroplastics, etc.) and undergo special process modification. Their brittle temperature can be as low as -40℃ or even lower, which can maintain good flexibility and mechanical strength in extreme low-temperature environments, effectively avoiding low-temperature brittleness. Therefore, whether PV cables become brittle at low temperatures depends on whether "PV-specific low-temperature resistant cables" are selected.
II. In-Depth Analysis: 3 Core Causes of Low-Temperature Brittleness of PV Cables
For PV cables that do not meet low-temperature resistance standards or misused ordinary cables, low-temperature brittleness is mainly caused by the following three factors, which are also one of the main causes of cable faults in PV power plants in cold regions:
1. Insufficient Low-Temperature Resistance of the Material Itself
The material of the cable insulation layer and sheath is the core determining its low-temperature performance. The brittle temperature of ordinary PVC materials is usually between -15℃ and -20℃. When the ambient temperature is lower than this range, the plasticizer inside the material will gradually lose its effect, the molecular chain rigidity will increase, and the cable will lose flexibility. Some low-cost PV cables, in order to control costs, do not use low-temperature resistant special materials, but only produce them through conventional materials, which are naturally prone to brittleness in cold environments.
2. Superposition of Mechanical Stress at Low Temperatures
PV cables themselves bear a certain amount of mechanical stress (such as bending, stretching) during laying. At low temperatures, the flexibility of the cable material decreases, and its ability to bear mechanical stress is greatly reduced. At the same time, external factors such as winter snow accumulation and low-temperature freeze-thaw leading to deformation of cable supports will further exert additional mechanical stress on the cables. When the stress exceeds the bearing limit of the cable material at low temperatures, it will cause cracking and brittle fracture of the insulation layer and sheath.
3. Material Aging Aggravates Low-Temperature Brittleness
PV cables are long-term exposed outdoors and need to withstand environmental impacts such as ultraviolet radiation and ozone erosion. These factors will accelerate the aging of the cable insulation layer and sheath, leading to decreased material performance. The aged material may still maintain basic performance at room temperature, but at low temperatures, its brittle temperature will increase, its low-temperature resistance will be further weakened, and it will be more prone to brittleness and fracture, greatly shortening the service life of the cable.
III. Key Impacts: 4 Major Hazards of Low-Temperature Brittleness to PV Power Plants
Low-temperature brittleness of PV cables will not only affect the service life of the cables themselves, but also bring serious hidden dangers to the safe and stable operation of PV power plants. The specific hazards are reflected in four aspects: Interruption of power transmission: After the cable insulation layer or sheath is brittle and cracked, the conductor may be exposed, causing faults such as short circuits and leakage, resulting in the failure of normal transmission of power generated by PV modules and affecting the power generation efficiency of the power plant;
- Risk of equipment damage: Short-circuit faults may damage core equipment such as inverters and combiner boxes, increasing the maintenance cost of the power plant;
Hidden safety hazards: Leakage and short circuits may cause safety accidents such as fires and electric shocks, threatening the personal safety of operation and maintenance personnel and the property safety of the power plant;
Increased operation and maintenance difficulty: In cold environments, the maintenance and replacement of brittle cables is difficult, and frequent faults will greatly increase the workload and cost of operation and maintenance.
IV. Scientific Response: Selection and Use Suggestions for PV Cables in Cold Regions
To avoid the brittleness of PV cables in low-temperature environments and ensure the safe and stable operation of the power plant, scientific responses should be made in three links: selection, laying, and operation and maintenance. The core is "selecting the right cable, standardized construction, and regular inspection".
1. Selection: Prioritize the Use of Low-Temperature Resistant PV-Specific Cables
Selection is the basis for resisting low-temperature brittleness, and three core indicators should be focused on: first, brittle temperature, prioritize cables with brittle temperature ≤ -40℃ to ensure adaptation to the local minimum temperature; second, material, prioritize cables with low-temperature resistant and aging-resistant materials such as cross-linked polyethylene (XLPE) and fluoroplastics, and avoid ordinary PVC cables; third, standard compliance, select PV-specific cables that meet the national standard GB/T 12706.1-2022 and international standard IEC 60228, and check the product test report to confirm that their low-temperature performance meets the standards.
2. Laying: Standardize Construction to Reduce Mechanical Stress Damage
When laying cables in low-temperature environments, special attention should be paid to reducing mechanical stress to avoid material damage: first, select the appropriate laying time, and try to lay when the temperature is relatively high at noon, when the cable flexibility is better; second, control the bending radius, strictly lay according to the minimum bending radius required by the cable manufacturer to avoid excessive bending; third, take protective measures, avoid the cable from contacting sharp objects during laying, and ensure that the inner wall of the pipe is smooth when laying through pipes to prevent scratching the cable; fourth, fix firmly, when fixing the cable on the bracket, use elastic fixing parts to avoid extrusion stress on the cable caused by bracket deformation due to low-temperature freeze-thaw.
3. Operation and Maintenance: Regular Inspection to Timely Handle Hidden Dangers
Cable inspection should be strengthened before and during winter to timely detect and handle brittleness hidden dangers: first, before winter, conduct a comprehensive inspection of the cable appearance, focusing on checking whether there are cracks and damage signs at cable joints, bends, and bracket connections; second, during winter, regularly remove snow and ice on the cable surface to avoid mechanical pressure on the cable caused by snow and ice accumulation; third, when signs of cable brittleness (such as stiffness, cracks) are found, timely replace the damaged cable section to avoid expanding the fault.