The design life of photovoltaic (PV) mounting structures is closely intertwined with their wind resistance capability, as both factors collectively determine the long-term safety and reliability of the system. Below is an analysis of their core relationship from technical logic, mutual influence, and engineering practice perspectives:
The wind resistance design of mounting structures is based on the wind load return period (e.g., 50-year or 100-year wind speed) of the target region, with the selection of the return period directly linked to the design life:
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Short design life (20 years): Typically uses a 50-year return period wind speed (with a 36% probability of occurrence within the life cycle). For example, China's GB 51096 standard requires PV mounting structures with a 25-year design life to be designed for 50-year wind loads.
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Long design life (over 25 years): Requires upgrading to a 100-year return period wind speed (probability reduced to 23%). For instance, ASCE 7 recommends using higher benchmarks for structures with a design life exceeding 50 years.
The longer the design life, the more significant the impact of material corrosion (e.g., steel rust, aluminum alloy oxidation) on structural strength:
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Coastal scenarios: Hot-dip galvanized steel (85μm coating) ensures 20 years of corrosion resistance, but a 25-year design life requires a corrosion allowance (thickness increased by 1-2mm). Otherwise, section weakening may reduce wind resistance by 10%-15%.
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Connection components: Bolt preload may 衰减 (decrease) by 1%-3% annually due to long-term wind vibration. For a 20-year design life, anti-loosening designs (e.g., nylon lock nuts) are required to maintain ≥90% torque retention.
Mounting structures must withstand at least one extreme wind event without catastrophic failure during their design life:
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Safety factor design: Wind loads typically use a safety factor of 1.5-2.0 to ensure elastic deformation under extreme conditions. For example, UL 2703 requires no collapse at 1.5× design wind speed.
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Damage tolerance: Local damage (e.g., individual bolt failure) is permissible, but overall stability must be maintained. Inadequate wind resistance (safety factor <1.0) can terminate the design life in a single extreme wind event.
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Life Stage
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Key Wind Resistance Focus
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Typical Measures
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Construction
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Wind resistance of bare frames (before module installation)
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Temporary cable reinforcement, checked against 10-year wind speed
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Operation
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Fatigue resistance + corrosion monitoring
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Annual bolt torque and structural deformation checks
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Decommissioning
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Wind safety during dismantling
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Wind-proof dismantling plans to avoid collapse of residual structures
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Special case for tracking structures: A 25-year design life requires addressing drive system fatigue (e.g., motor overload protection) and mechanical clearance accumulation (using self-lubricating materials) to maintain ≥85% of initial wind resistance stiffness.
Enhancing wind resistance (e.g., upgrading steel grades, enlarging foundations) increases upfront costs. Risk-quantified analysis is needed for balance:
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Typhoon-prone region case: Upgrading a 20-year structure to 100-year wind design increases costs by 15% but reduces typhoon damage risks by 30%. Feasibility requires an internal rate of return (IRR) >8%.
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Modular design: Design vulnerable components (e.g., anchor bolts) as replaceable modules, with preventive replacement at mid-life (15 years) to maintain wind resistance at low cost.
Global warming may increase extreme wind speeds, requiring design margins:
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Wind speed upgrade margin: Design at 1.1× current 100-year wind speed to offset 20-25 years of climate risk.
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Smart monitoring: Use IoT sensors to real-time monitor wind speed and stress, activating emergency reinforcement (e.g., temporary hydraulic supports) when exceeding design thresholds.
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Standard
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Design Life Requirement
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Core Wind Resistance Provisions
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UL 2703
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20 years
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No permanent deformation at design wind speed; no collapse at 1.5× design wind speed
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Eurocode 1
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25+ years
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Differentiate normal vs. extreme wind conditions; fatigue life verification
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GB 51096
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25 years
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Design for 50-year wind loads; check stability under combined ice and wind loads
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A mounting structure with a 15-year design life suffered 10% steel section weakening at year 12 due to lack of corrosion allowance, causing column buckling at 28m/s wind speed (design: 30m/s).
Lesson: Design life and material durability must be synchronized, with coastal areas requiring 5-year corrosion coating inspections.
A tracking structure with a safety factor of 1.1 (standard ≥1.5) collapsed at year 5 due to drive shaft failure during a 35m/s typhoon (design: 32m/s).
Lesson: Wind resistance safety factors are foundational to design life; low standards lead to early failure.
Design life and wind resistance are unified in time and mechanical performance: the former sets the load benchmark and durability boundary for wind resistance design, while the latter provides safety guarantees for achieving the design life. In engineering, full-lifecycle coordination of load-material-structure design is essential to find the optimal balance between cost and risk, ensuring mounting structures reliably withstand target wind environments throughout their intended service life.
Polski
System montażu naziemnego
system mocowania na dachu
System mocowania wiaty garażowej
system mocowania farmy
Easy Solar Kit
system śledzenia słonecznego
Falownik słoneczny
Akcesoria słoneczne
RM502, Sihai Smart Zone, No.189, Fanghu West Road, Huli District, Xiamen, Fujian, China.
