In regions known for extreme sunlight and scorching temperatures—like the Middle East, Africa, and South Asia—solar cables are regularly exposed to surface temperatures soaring past 70°C during peak summer months. While some projects cut corners by selecting lower-cost cables, many end up relying on materials such as PVC, which lack the resilience to withstand prolonged thermal stress. The result? Premature aging and significant long-term safety concerns.
So, what exactly happens when heat starts to degrade a solar cable? What are the warning signs, and how does it impact performance? Let's delve into the science behind heat-induced aging.
1. Deep Inside the Cable: The Chemistry of Degradation
The protective layers of solar cables—insulation and sheathing—are generally made from polymers. Yet, lower-end options often use thermally unstable materials like PVC. When exposed to sustained high heat, these materials undergo multiple forms of degradation:• Thermal Oxidation
Heat speeds up the interaction between oxygen and polymer chains. This initiates free-radical reactions that sever molecular bonds, leading to a weakened structure and deteriorated insulation.
• Loss of Plasticizers
In PVC, plasticizers are added to maintain flexibility. But under high temperatures, they slowly evaporate, making the material rigid, brittle, and more prone to cracking.
• Emission of Corrosive Gases
Heat can also cause PVC to release gases like hydrogen chloride. These can damage surrounding components—especially metal—escalating system-wide risks.
2. What Aging Looks Like: Surface-Level Clues
Though degradation starts at the molecular level, it doesn’t stay hidden forever. As the material breaks down, visible warning signs begin to emerge:
Color fading or graying – signaling antioxidant depletion
Cracks or fine fractures – indicating insulation damage
Powdering or surface chalking – a symptom of material embrittlement
Blistering or stickiness – caused by trapped gases or migrating additives
These external changes reflect internal failure and often precede functional breakdown.
3. Beyond Wear and Tear: Real-World Hazards
Heat-aged cables are not only unsightly—they're dangerous. Here’s what can happen:
• Electrical Failures & Fire Risks
Cracked insulation can allow moisture ingress or lead to electrical arcs, increasing the likelihood of short circuits or fires.
• Structural Fragility
Aged cables lose their flexibility, making them vulnerable to snapping, especially during handling or under environmental stressors.
• Efficiency Loss & Higher Costs
As resistance increases and insulation weakens, energy losses rise. The need for repair or full replacement grows more frequent, driving up operating expenses.
4. The False Economy of Cheap PV Cables
Opting for lower-quality materials may reduce initial costs—but the consequences in hot environments can be severe:
Frequent breakdowns and shorter cable lifespans
Compromised system safety and reliability
Cumulative expenses that overshadow early savings
Final Thought: Heat Damage Starts Before You Notice It
Extreme heat is a hidden enemy of solar infrastructure. By the time visible symptoms appear, deeper internal damage has already taken place. What seems like a harmless crack may signal a much larger issue beneath the surface.
Investing in high-quality, thermally stable Solar cables isn't just a smart engineering choice—it’s a long-term safeguard for safety, performance, and total system value. When it comes to solar cable selection in high-heat regions, cutting corners today can mean paying a far greater price tomorrow.
