What external factors may affect Photovoltaic Bolts during long-term use?

Photovoltaic bolts will be affected by a variety of external factors during long-term use. These factors may come from the natural environment, mechanical stress or chemical action, which directly affect the performance, life and reliability of the bolts. The following is a detailed analysis:

Temperature change
Impact: Temperature fluctuations will cause thermal expansion and contraction effects of materials, especially in extreme climate conditions (such as hot desert areas or cold polar regions). This repeated expansion and contraction may cause the gap between the bolt and the connector to increase, thereby reducing the tightening force.
Consequences: Bolt loosening and reduced preload may cause instability of photovoltaic modules or bracket systems.
Countermeasures: Select materials with excellent temperature resistance (such as stainless steel or high-strength alloy steel) and ensure that the torque value is appropriate during installation.
Ultraviolet radiation
Impact: Long-term exposure to sunlight may cause aging of the coating or sealing materials on the bolt surface, especially organic coatings or rubber washers.
Consequences: Coating peeling, accelerated corrosion, and even bolt failure may occur.
Countermeasures: Use UV-resistant coating materials (such as ceramic coatings or fluorocarbon paints), or choose bare metal surfaces to reduce coating aging problems.
Humidity and corrosion
Impact: High humidity environments (such as coastal areas or rainforest climates) can easily cause electrochemical corrosion of bolts, especially ordinary steel or low-quality galvanized layers.
Consequences: Bolt strength decreases, the risk of breakage increases, and the overall safety of the photovoltaic system may be affected.
Countermeasures:
Use corrosion-resistant materials (such as stainless steel 304/316, aluminum alloy or titanium alloy).
Add anti-corrosion treatment (such as hot-dip galvanizing, Dacromet coating or passivation treatment).
Regularly check and maintain the surface of the bolts and clean up corrosion products in time.
Wind load and vibration
Impact: PV systems are usually installed outdoors and are subjected to wind loads and vibrations (such as resonance caused by wind) for a long time. These dynamic loads impose additional stress on the bolts.

Consequences: Fatigue damage, thread wear or bolt loosening may lead to structural failure.
Countermeasures:
Consider fatigue resistance when designing and choose high-strength bolts.
Use anti-loosening devices (such as double nuts, spring washers or chemical anti-loosening glue).
Check the tightness of the bolts regularly and re-apply the appropriate torque.
Salt spray and chemical corrosion
Impact: In coastal areas or environments with severe industrial pollution, salt spray and acidic gases (such as sulfur dioxide and chlorides) will accelerate the corrosion of bolts.
Consequences: Rust spots, cracks, and even complete failure of bolts appear on the surface.
Countermeasures:
Use materials that are resistant to salt spray corrosion (such as stainless steel 316L).
Add a protective layer (such as epoxy resin coating or PVD coating) on ​​the surface of the bolts.
Avoid contact between different metals to prevent electrochemical corrosion.
Dust and particulate matter
Impact: In deserts or areas with strong winds and sand, dust particles may enter the threaded area, causing bolts to wear or get stuck.
Consequences: Bolts are difficult to remove or replace, and maintenance costs increase.
Countermeasures:
Use closed designs (such as bolts with sealing covers).
Clean the surface of the bolts regularly to prevent particle accumulation.
Mechanical shock and external forces
Impact: PV systems may be subject to unexpected mechanical shocks (such as hail, tree branch impacts, or human damage), which may directly damage or deform the bolts.
Consequences: Bolts lose their tightening function, which may cause PV panels to fall off or brackets to collapse.
Countermeasures:
Improve the impact resistance of bolts and choose high strength grades (such as 8.8 or 10.9).
Add redundant safety factors in the design to ensure that the system can still operate normally even if some bolts fail.
Biological erosion
Impact: In certain specific environments (such as wetlands or near the ocean), microbial activity may cause biological corrosion, especially when there are organic residues on the surface of the bolts.
Consequences: The surface of the bolts is gradually eroded and the strength is weakened.
Countermeasures:
Use antibacterial coatings or inorganic materials.
Clean the surface of the bolts regularly to avoid the accumulation of organic matter.
Installation errors and improper maintenance
Impact: Improper torque control during installation, failure to use anti-loosening devices or untimely maintenance will accelerate the aging and failure of bolts.
Consequences: Loose bolts and insufficient preload will eventually affect the stability of the photovoltaic system.
Countermeasures:
Develop strict installation specifications to ensure that the torque value meets the design requirements.
Perform regular inspections and maintenance to detect and solve problems in a timely manner.

Photovoltaic bolts need to face complex external environments during long-term use, including temperature changes, ultraviolet radiation, humidity corrosion, wind load, salt spray erosion and other factors. In order to extend their service life and ensure the safety and reliability of photovoltaic systems, comprehensive consideration must be given to multiple aspects such as material selection, design optimization, installation specifications and post-maintenance. By selecting high-performance materials, taking appropriate protective measures and regular inspection and maintenance, the impact of external factors on photovoltaic bolts can be effectively reduced.