In solar power plants, trackers are among the most mechanically demanding systems. They incorporate continuous movement, variable loads, and repetitive cycles throughout the entire service life of the project.
In this context, fasteners play a central role in the operation and reliability of the system. Although they often go unnoticed, fasteners connect structures, enable tracker movement, and directly influence overall plant availability.
Where Fasteners Are Used in Solar Trackers
Fasteners are present at all critical points of the system:
- Main Structural Connections
- Rotation Axles And Moving Supports
- Arms And Transmission Mechanisms
- Photovoltaic Module Fixation
- Subassemblies Requiring Adjustment Or Field Maintenance
Each of these joints is subjected to movement and cyclic loads, which significantly increases the demands placed on bolts, nuts, and washers compared to static systems.
Why Fasteners Are So Important in Trackers
In a solar tracking system, fasteners do more than simply hold components together: they actively participate in the operation of the tracker.
Their proper performance allows to:
- Maintain Movement Accuracy
- Prevent Torque Loss In Joints
- Ensure Stable Mechanical Behavior Over Time
When fasteners do not perform as expected, the impact quickly spreads to the entire system and, as a result, to the overall performance of the solar plant.
How Corrosion Affects Fasteners in Solar Trackers
Corrosion is one of the main issues affecting fasteners.
Corrosion can lead to:
- Increased Friction In Threads
- Difficulties In Adjustment And Retightening
- Alterations In Torque–Tension Behavior
In solar trackers, these effects result in reduced tracking accuracy, premature component wear, and the need for unplanned interventions. At the project level, this directly impacts plant availability as well as operation and maintenance costs.
Surface Treatments: From Traditional Solutions to Modern Approaches
Hot-dip galvanizing has historically been a valid solution for protecting large structural components in solar power plants. Its robustness makes it suitable for certain parts of the system.
However, in tracker fasteners, this treatment presents well-known limitations, such as excessive coating thickness that affects tolerances and poorly controlled friction behavior—especially in systems with continuous movement.
For this reason, the industry has adopted modern surface treatments, such as zinc flake coatings, which complement hot-dip galvanizing within the same project.
While hot-dip galvanizing remains a valid option for main structural elements, zinc flake coatings are used on fasteners and critical joints where the following are required:
- Controlled Coating Thickness
- Preservation Of Tolerances
- Stable Mechanical Behavior
- High Corrosion Resistance
This combined approach is already applied in large-scale solar projects, such as Cauchari Solar Park and El Quemado Solar Park, where system reliability is a key factor.
Conclusion
In solar trackers, fasteners play a key role in system operation and plant availability. When these joints degrade due to corrosion, the impact is quickly transferred to tracker performance and overall plant operation.
For this reason, the selection of surface treatment is not a minor detail. Using modern solutions, such as zinc flake coatings, in a complementary way to traditional treatments allows fasteners to be protected without compromising tolerances or functionality.
