Ⅰ. What Are Solar Screws?
Solar screws are high-strength fasteners specifically designed for solar power generation systems, mainly used to fix equipment such as photovoltaic panels, brackets, inverters, and cables. Their core requirements are to work stably for a long time in extreme environments (such as high temperatures, ultraviolet rays, salt spray, sand, and wind) while having characteristics such as corrosion resistance, high load-bearing capacity, and weather resistance. Common materials include stainless steel (such as 304, 316), aluminum alloy, carbon steel with galvanization, titanium alloy, and engineering plastic composites for some special environments.
Ⅱ. Core Performance Advantages of Solar Screws
1. Excellent Weather Resistance
Solar energy systems are usually installed outdoors and exposed to ultraviolet rays, high temperatures, rain and snow, salt spray, and other environments for a long time. Solar screws need to be made of materials with excellent weather resistance (such as 316 stainless steel), and their surfaces are treated with coatings (such as galvanizing, titanium plating), which can resist ultraviolet aging and chemical corrosion, ensuring a service life of more than 25 years.
2. High Strength and Fatigue Resistance
Photovoltaic systems need to withstand dynamic loads such as wind pressure, snow load, and earthquakes, especially in coastal or high-wind-speed areas. Solar screws need to have high yield strength (for example, stainless steel screws can reach 500-800MPa) and fatigue resistance to avoid loosening or 断裂 caused by long-term vibration or alternating stress.
3. Corrosion Resistance
In coastal areas or regions with severe industrial pollution, salt spray and acid rain will accelerate metal corrosion. Solar screws usually choose 316 stainless steel (resistant to chloride ion corrosion) or carbon steel treated with hot-dip galvanizing to ensure long-term stability in harsh environments.
4. Balance Between Insulation and Conductivity
In some scenarios, it is necessary to prevent current leakage or electromagnetic interference. At this time, screws made of insulating materials (such as coating treatment or composite materials) can be selected; while in grounding systems that require conductivity, high-conductivity metals (such as copper alloys) need to be chosen.
5. Anti-Loosening and Self-Locking Design
To cope with outdoor vibration, some solar screws adopt a thread self-locking structure or nylon inserts to prevent loosening and falling off after long-term use, improving system safety.
Ⅲ. Application Scenarios of Solar Screws
1. Fixing of Photovoltaic Modules
Solar screws are the main connecting parts between photovoltaic panels and aluminum alloy brackets, which need to bear the weight of the modules (usually about 20-30kg per piece) and external loads, while ensuring installation accuracy.
2. Connection of Bracket Systems
The node connection of bracket structures (such as fixed inclined, tracking brackets) relies on high-strength screws to ensure the stability of the structure under wind loads.
3. Fixing of Inverters and Cables
Equipment such as inverter enclosures and cable junction boxes need to be fixed with high-temperature-resistant and insulating screws to avoid poor contact caused by vibration or temperature changes.
4. Roof and Ground Installation Systems
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Roof Installation: It is necessary to penetrate tiles or concrete roofs. Screws need to have waterproof and sealing performance (such as self-tapping screws with rubber gaskets).
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Ground Installation: Used to fix pile foundations and brackets, need to bear greater vertical and horizontal loads, usually long bolts or anchor bolts are selected.
Ⅳ. Key Points for Selection and Installation of Solar Screws
1. Material Selection
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Coastal/high salt spray environments: Priority is given to 316 stainless steel or titanium alloy.
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Highly corrosive industrial areas: Hot-dip galvanized carbon steel or epoxy resin-coated screws are recommended.
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High-temperature areas: The thermal expansion coefficient of the material needs to be considered to avoid loosening caused by temperature differences.
2. Specification and Strength Matching
Calculate the required screw diameter, length, and thread specifications according to the system design load (such as wind speed, snow load). For example, ground brackets usually use high-strength bolts of M10-M16, with lengths up to 300mm or more.
3. Surface Treatment Processes
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Electro-galvanizing: Low cost, suitable for general environments.
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Dacromet coating: Better corrosion resistance than electroplating, suitable for humid areas.
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Parkerizing (phosphating treatment): Enhances rust resistance and lubricity, facilitating installation.
