Selection and optimization strategies of photovoltaic brackets in different climate zones

During the implementation of photovoltaic power generation projects, climatic conditions are key factors affecting the performance and lifespan of photovoltaic mounting systems. High temperatures and high humidity can easily lead to mounting corrosion, severe cold and snow can test the mounting's load-bearing capacity, and strong winds and sandstorms can cause mounting wear and structural deformation. This article analyzes the core challenges facing photovoltaic mounting systems in four typical climate zones and proposes appropriate selection solutions and optimization strategies to help improve the stability and cost-effectiveness of photovoltaic systems in complex climates.

I. High-Temperature and High-Humidity Climate Zones: Prioritizing Corrosion Prevention and Heat Dissipation

(I) Climate Characteristics and Core Challenges

South my country (such as Guangdong and Hainan) and parts of Southwest China (such as Yunnan) belong to high-temperature and high-humidity climate zones, with average annual temperatures ranging from 22-28°C and relative humidity frequently exceeding 75%. Some areas are also subject to typhoons and heavy rains. Mounting systems face two key challenges: First, high temperatures accelerate metal oxidation, and high humidity exacerbates electrochemical corrosion, making traditional steel mounting systems susceptible to rust penetration. Second, high temperatures increase the operating temperature of photovoltaic modules (for every 1°C increase, power generation efficiency decreases by approximately 0.4%-0.5%). If the mounting system cannot provide adequate heat dissipation, the system's power generation capacity will be further reduced. (II) Model Selection and Optimization
Material Selection: Aluminum Alloy and Corrosion-Resistant Steel are Preferred
6061-T6 aluminum alloy brackets are recommended. They offer excellent salt spray corrosion resistance (corrosion rate ≤0.005mm/year in a 5% salt spray environment) and high thermal conductivity (approximately 205W/(m・K)). They conduct heat from the modules to the air through the brackets, assisting in heat dissipation. For example, a rooftop photovoltaic project in Wenchang, Hainan, using aluminum alloy brackets reduced module operating temperatures by 3-5°C compared to traditional steel brackets, increasing annual power generation by approximately 2%.
If steel brackets are chosen, they must be treated with a dual corrosion protection method of "hot-dip galvanizing + fluorocarbon spraying." The zinc layer should be ≥120μm thick, and the fluorocarbon coating should be ≥60μm thick. This ensures a corrosion lifespan of at least 25 years. Thermal insulation pads (such as silicone pads) should be installed at the contact points between the brackets and the modules to reduce heat transfer to the modules. Structural Optimization: Enhanced Ventilation and Wind Resistance

The ground bracket utilizes an elevated design, with the base of the bracket at least 1.5 meters above the ground, to accelerate heat dissipation through air convection. The roof bracket utilizes an inclined crossbeam to prevent rainwater from accumulating on the bracket's top, reducing the risk of corrosion in humid environments.

For typhoon-prone areas, the bracket columns utilize a tapered structure (base diameter ≥ 150mm, top diameter ≥ 100mm) to enhance wind resistance and stability. Locknuts (such as Spirax nuts) are installed on bracket connectors to prevent bolt loosening caused by typhoons.​
II. Severely Cold and Snowy Climates: Strengthening Bearing and Frost Resistance
(I) Climate Characteristics and Core Challenges
Northeast my country (such as Heilongjiang and Jilin) ​​and parts of Northwest China (such as Altay, Xinjiang) belong to severely cold and snowy climates. Winter temperatures can reach below -30°C, and snow depths often exceed 50cm. Some areas experience freeze-thaw cycles, presenting three major challenges for support structures: First, heavy snow loads (reaching 1.5-2.0 kN/m² in some areas) can easily cause support beams to bend and columns to deform. Second, low temperatures increase the brittleness of metal materials, making support structures susceptible to fracture under impact loads (such as falling snow). Third, freeze-thaw cycles (soil expansion upon freezing and contraction upon thawing) can damage support foundations and cause them to tilt. (II) Selection and Optimization
Structural Selection: Heavy-Duty and Frost-Resistant Design
Q355ND low-temperature toughness steel supports are preferred. Its impact energy at -40°C is ≥34J, making it resistant to low-temperature brittle fracture. Furthermore, the support beams feature an I-section (cross-section height ≥100mm), which increases bending strength by over 40% compared to conventional C-section steel and can withstand snow loads of 2.0kN/m². For example, a ground-mounted photovoltaic power station in Daqing, Heilongjiang, which used Q355ND steel supports, experienced no structural damage after three heavy snowstorms (snow depth of 60cm).

The foundation is constructed with cast-in-place concrete piles (diameter ≥600mm, buried ≥2.5m deep), which penetrate the permafrost to prevent freezing and thawing. Elastic cushioning (such as rubber pads) is installed at the junctions between the support columns and the foundation to absorb stress caused by frost heave.
Operation and Maintenance Optimization: Snow Removal and Low-Temperature Protection

The tracking brackets are equipped with an automatic snow removal system. This system rotates the brackets (at an angle of ≥45°) to allow snow to slide off, reducing manual clearing costs. The fixed brackets are designed with an inclination angle of ≥35°, leveraging gravity to accelerate snow sliding and prevent prolonged snow accumulation.

Before winter arrives, the bracket bolts are lubricated with a special -40°C grease to prevent them from freezing and becoming unadjustable. Ultrasonic testing is also performed on bracket welds to promptly repair any microcracks that may develop at low temperatures.​
III. Highly Windy and Sandy Climate Zones: Balancing Wear Resistance and Sandstorm Prevention
(I) Climate Characteristics and Core Challenges
Northwest my country (e.g., the Taklamakan Desert in Xinjiang and Jiuquan in Gansu) belongs to a high-windy and sandstorm climate zone, with average annual wind speeds of 3-5 m/s, peak speeds exceeding 25 m/s, and 5-15 sandstorms annually. This presents two major challenges for support structures: First, the quartz sand (hardness 7H) contained in the windblown sand can abrade the support surface, damaging the anti-corrosion coating and accelerating support corrosion; second, strong wind loads can easily cause support resonance. Long-term resonance can loosen support connectors and even cause support collapse. (II) Model Selection and Optimization

Materials and Structure: Wear-Resistant, Corrosion-Resistant, and Anti-Resonance Design

The bracket surface is treated with a ceramic coating (thickness ≥ 80μm). The ceramic coating has a hardness of 9H, making it over five times more wear-resistant than traditional hot-dip galvanizing and resistant to wind and sand abrasion. 201 stainless steel (nickel content 1%-3%) is the preferred material, offering both wear and corrosion resistance, making it suitable for desert environments. For example, a desert photovoltaic power station in Shanshan, Xinjiang, using ceramic-coated 201 stainless steel brackets, has shown surface wear of only 0.02mm over three years, far less than the 0.1mm of traditional brackets. The tracking bracket utilizes a low-wind-speed start-up design (start-up wind speed ≤ 2m/s) to reduce sand accumulation caused by the bracket being stationary before strong winds. Wind tunnel testing and optimization of the bracket structure have reduced the bracket's drag coefficient by 30%, reducing wind loads in strong winds. Dampers are also installed at the base of the bracket columns to suppress bracket resonance, keeping the amplitude below 0.5mm.

Installation Optimization: Wind and Sand Protection and Easy Cleaning

A wind-proof sand shield (≥50cm tall, made of fiberglass) is installed at the bottom of the bracket to reduce sand erosion on the bracket foundation. The ground bracket utilizes a spiral pile foundation (spiral blade diameter ≥300mm) for quick fixation in the sand layer while preventing sand from entering through gaps in the foundation.

A 10-15mm gap is maintained between the bracket and the module to prevent sand from accumulating in the gap and affecting module heat dissipation. The bracket is regularly cleaned with a high-pressure water jet (pressure ≤0.8MPa) to remove dust adhering to the bracket surface and prevent prolonged dust buildup that could affect heat dissipation. Coastal Salt Fog Climate Zone: High-Level Corrosion Protection is Key
(I) Climate Characteristics and Core Challenges
my country's southeastern coastal areas (such as the coastal areas of Zhejiang, Fujian, and Guangdong) belong to the coastal salt fog climate zone. Salt fog concentrations in the air are high (chloride ion concentrations ≥ 50 mg/m³). Chloride ions in the salt fog can penetrate metal anti-corrosion coatings, causing pitting and crevice corrosion. Furthermore, typhoons are frequent in coastal areas (with maximum wind speeds exceeding force 12). Brackets face the dual challenges of "high corrosion and strong wind loads." In this environment, the lifespan of traditional brackets is often shortened to 10-15 years, far below the designed lifespan of 25 years. (II) Selection and Optimization
Material Selection: Highly Corrosion-Resistant Materials are Preferred
Super duplex stainless steel (2507) is recommended for brackets. It contains 25% chromium, 7% nickel, and 4% molybdenum. Its corrosion rate in salt spray environments is ≤0.001mm/year, making it over 10 times more corrosion-resistant than ordinary 304 stainless steel. Its tensile strength exceeds 800MPa, allowing it to withstand a Category 12 typhoon (wind load ≥3.0kN/m²). For example, an offshore photovoltaic power station in Ningde, Fujian, using 2507 super duplex stainless steel brackets has shown no corrosion over its five-year service life.

If cost is a constraint, a triple-layer corrosion protection scheme of "hot-dip galvanizing + passivation + sealing" steel brackets can be used. The zinc layer is ≥150μm thick, the passivation layer is chromate-based, and the sealing layer is polyamide resin. This triple layer of protection can extend the bracket life to over 20 years.
Structure and Installation: Typhoon-Resistant and Corrosion-Proof Details

The PV mount utilizes a triangular truss structure to enhance overall stability, with truss spacing ≤2m to minimize structural deformation in strong winds. The tracking mount utilizes dual-drive motors to quickly adjust the modules to a downwind angle (≤15° with the wind direction) before a typhoon approaches, reducing wind loads.

All mounting connections utilize stainless steel bolts (316L), and fluororubber seals are installed at the contact points between the bolts and the mount to prevent salt spray from entering through the gaps. The mount welds utilize argon arc welding followed by pickling and passivation to eliminate residual stress and prevent them from becoming corrosion vulnerabilities.

V. Conclusion

Selecting PV mounts for different climate zones is essentially a matter of precisely matching climate challenges with technical solutions. High-temperature and high-humidity regions require a balance between corrosion protection and heat dissipation; severely cold and snowy regions require enhanced load-bearing and frost resistance; areas with strong winds and sandstorms require both wear resistance and wind protection; and coastal salt spray areas require a focus on high-level corrosion protection. In the future, with advances in material technology (such as new corrosion-resistant composite materials) and structural design (such as adaptive wind-resistant structures), photovoltaic brackets will become more "climate-adaptable," providing more reliable and economical support for photovoltaic power generation projects in different climate zones around the world, and promoting the widespread application of new energy in complex environments.