In most photovoltaic (PV) projects, attention is naturally drawn to the most visible and high-value components.
Modules, inverters, and tracking systems dominate technical discussions and procurement priorities—especially when sourced from leading manufacturers.
This focus is understandable. These components define system capacity, efficiency, and, to a large extent, investment scale.
However, it can also create a blind spot.
Because in real-world operation, system reliability is not only determined by the most advanced components—but also by the most vulnerable connections between them.
And this is where cables quietly become critical.
The Nature of Failures in PV Systems
When people think about system failure, they often imagine major equipment malfunction: inverter shutdowns, module defects, or structural issues.
In reality, many operational disruptions originate from much smaller points within the system.
Electrical systems are inherently interconnected.
A single weak link—particularly in current transmission—can affect the performance of an entire string or section.
Cables, as the physical medium of energy transmission, are present at every stage:
Between modules
Across strings
From combiner boxes to inverters
Throughout long-distance routing in utility-scale plants
This extensive presence means that even a low probability of failure at each point can translate into a meaningful system-level risk.
Why Cable Failures Are Often Overlooked
One of the reasons cable-related issues receive less attention is their lack of visibility.
Unlike modules or inverters, cables do not have monitoring interfaces.
Their degradation is typically gradual and occurs beneath insulation layers, making early-stage issues difficult to detect.
In many cases, cable failures follow a pattern:
Initial installation appears normal
Performance remains stable in early operation
Gradual material degradation occurs due to environmental stress
Failures emerge after several years, often outside warranty focus
By the time issues become visible—such as insulation cracks or electrical faults—the root cause may already be widespread.
Environmental Stress and Long-Term Degradation
Cables operate continuously under environmental conditions that are both demanding and persistent:
Ultraviolet (UV) radiation
High ambient temperatures
Daily thermal cycling
Moisture exposure
These factors do not act independently.
Their combined effect accelerates material aging, particularly in lower-quality insulation and jacket compounds.
Over time, this can lead to:
Loss of mechanical flexibility
Surface embrittlement and cracking
Reduced insulation resistance
Increased likelihood of leakage currents or short circuits
Such degradation is rarely sudden.
It is progressive, and therefore more difficult to manage.
System-Level Impact of Local Failures
A key characteristic of PV systems is their sensitivity to localized issues.
For example, in a typical string configuration, the performance of the entire string can be affected by a single point of failure.
When a cable fault occurs, potential consequences include:
Reduced energy output from affected strings
Increased difficulty in fault localization
Additional maintenance interventions
Temporary or extended system downtime
In large-scale installations with thousands of connection points, even a small failure rate can lead to a significant operational burden over time.
The Misalignment in Procurement Priorities
Despite these risks, cable selection is often treated as a secondary decision.
This creates a structural misalignment:
High-value components are optimized for performance and longevity
Low-cost components are selected with minimal long-term evaluation
From a systems engineering perspective, this approach introduces inconsistency.
A system designed for 25+ years of operation becomes partially dependent on components that may not be engineered for the same lifespan.
Rethinking “Critical Components”
Traditionally, “critical components” are defined by cost, complexity, or visibility.
However, in reliability engineering, criticality is better defined by impact on system performance.
From this perspective, cables meet all the criteria:
They are essential for energy transmission
They are widely distributed across the system
Their failure can affect entire sections of operation
Their degradation is difficult to detect early
In other words, cables may not be the most expensive components,
but they are among the most system-critical.
A More Balanced Approach to Risk
Improving system reliability does not necessarily require over-engineering every component.
Instead, it requires alignment:
Aligning component lifespan with system design life
Aligning material performance with environmental conditions
Aligning procurement decisions with long-term operational goals
In this context, cables should be evaluated not as low-cost accessories, but as integral parts of the system’s reliability architecture.
Conclusion
In PV projects, the most significant risks are not always associated with the components that receive the most attention.
They often arise from those that are underestimated during planning and procurement.
Cables fall into this category.
Recognizing their role does not mean shifting focus away from modules or inverters, but rather adopting a more holistic view of system reliability—one that considers not only how energy is generated, but also how it is transmitted over time.
For those involved in project design, engineering, or procurement, an important question remains:
Are your most critical components defined by their cost—or by their impact on system performance?
