Guide to Selecting Solar Street Light Poles

1. Basic Principles for Selecting Solar Street Light Poles

• Functionality Principle
  • The pole must safely and steadily support the load of the arm and lighting fixtures.
  • The design should ensure normal operation under various weather conditions (e.g., wind, rain, snow).
• Practical Principle
  • Installation should be straightforward, with minimized maintenance costs.
  • The expected lifespan of the pole should be over 10 years to reduce the hassle and costs of frequent replacements.
• Economic Rationality Principle
  • Avoid unnecessary expenditures when constructing new poles solely for aesthetic purposes.
  • Maintenance costs should also be reasonable, avoiding excessive expenses due to a focus on appearance.
• Safety Principle
  • Poles are subjected to rain, sun, and wind, and those buried in soil may also be corroded by soil acidity and alkalinity.
  • The wall thickness of the pole should generally not be less than 4 mm to ensure sufficient mechanical strength.
  • Corrosion resistance measures should include at least one effective anti-corrosion treatment, such as hot-dip galvanizing.
• Aesthetic Principle
  • The smoothness and geometric dimensions of the pole should be harmonized, but excessive pursuit of unnecessary beauty that increases costs should be avoided.
  • The color and shape should blend with the surrounding environment, avoiding light pollution.

2. Main Content of Pole Selection

• Height SelectionThe height of the pole should be determined based on the road width, lighting fixture photometric type, installation method, and spacing.
  

  Recommended Heights and Spacing Based on Photometric Type and Installation Method

  • Cut-off Type:
    • Single-side installation: H > 0.5w, S < 3H
    • Staggered installation: H > 0.7w, S < 3H
    • Symmetrical installation: H > 0.5w, S < 3H
  • Semi-cut-off Type:
    • Single-side installation: H > 1.2w, S < 3.5H
    • Staggered installation: H > 0.8w, S < 3.5H
    • Symmetrical installation: H > 0.6w, S < 3.5H
  • Non-cut-off Type:
    • Single-side installation: H > 1.4w, S < 4H
    • Staggered installation: H > 0.9w, S < 4H
    • Symmetrical installation: H > 0.7w, S < 4H

  Note: In the table, w refers to the effective width of the road, H is the height of the pole, and S is the spacing between poles.

• Material Selection
  • Ordinary Steel Plate: Economical and able to meet loading requirements, currently the most commonly used material.
  • Stainless Steel: Aesthetically pleasing and durable, but more expensive, and prone to light pollution under sunlight; mainly used in special locations (such as tourist attractions or high-end communities).
  • Ceramic: Has unique cultural characteristics but has poor mechanical strength; not suitable for widespread use.
• Corrosion Resistance Selection
  • Hot-Dip Galvanizing: The ideal corrosion treatment method, effective in preventing corrosion and is cost-effective.
  • Hot-Dip Galvanizing with Spray Coating: Although aesthetically pleasing when new, it may flake after 3-5 years, increasing maintenance workload and costs; not widely recommended.
  • Painting: Can serve as an alternative when inputs or time are limited, but protective effects are not as good as hot-dip galvanizing.
• Pole Shape Selection
  • Single-Tube Conical Shape: Economical and practical, with good mechanical strength; suitable for most roadway lighting.
  • Single-Tube Polygonal: Also economical and practical, offers good mechanical strength; suitable for various settings.
  • Equal Diameter Double-Tube Combination: Complex structure, higher costs; not recommended for general use.
  • Non-Equal Diameter Double-Tube Combination: Complex structure, higher costs; not recommended for general use.
  • Once-Formed Cantilever Shape: Suitable for specific lighting needs, such as in squares and parks.
• Recommended wall thickness varies based on pole height:
  • 2-4m poles: Minimum 2.5cm
  • 4-9m poles: Minimum 4-4.5cm
  • 8-15m poles: Minimum 6cm
• Areas prone to strong winds may require thicker wall thickness for added durability.

3. Specific Indicators for Solar Street Light Poles

• Height:
  • Fast Roads: Average illumination 20 lx, uniformity 0.4, suggested pole height 10-12 meters.
  • Main Roads: Average illumination 15 lx, uniformity 0.35, suggested pole height 8-10 meters.
  • Secondary Roads: Average illumination 8 lx, uniformity 0.35, suggested pole height 6-8 meters.
  • Branches: Average illumination 5 lx, uniformity 0.3, suggested pole height 4-6 meters.
  • Sidewalks, Commercial Pedestrian Streets, Residential Communities: Suggested pole height 3-5 meters.
• Wall Thickness:The wall thickness should not be less than 4 mm to ensure adequate mechanical strength and wind resistance.
• Corrosion Resistance:
  • Pole should be hot-dip galvanized to prevent corrosion from acidic and alkaline substances in the soil.
  • For exposed parts, it is recommended to use hot-dip galvanizing with spray coating to enhance appearance and protection.
• Wind Resistance Level:
  • Coastal or Typhoon Areas: Poles should withstand a level 12 typhoon, with maximum wind speeds up to 32.7 m/s.
  • Inland Areas: Poles should withstand level 10 winds, with maximum wind speeds up to 24.5 m/s.

  Wind Resistance Design Formula:

  P = (1 + C)ρV²/2

  where:
  P: wind pressure, units: N/m².
  C: structural constant that varies with shape, ranging from 0.3 (cylindrical) to 1.0 (flat).
  ρ: air density, approximately 1.25 kg/m³ at room temperature.
  V: wind speed perpendicular to the surface, units: m/s.

4. Design of the Solar Street Light Pole and Fixture Shell

• Pole Design:
  • The height should be determined based on the road width, fixture spacing, and expected illumination standards.
  • The design should consider materials’ mechanical strength, wind resistance, and corrosion performance.
  • The appearance should be simple and practical, avoiding complex decorative designs to minimize maintenance costs.
• Fixture Shell Design:
  • Fixture shells should be sturdy enough to protect internal electrical components from environmental impact.
  • They should have good heat dissipation performance to dissipate heat generated by the light source and electrical components.
  • Fixture shells should meet certain sealing levels to prevent rainwater, dust, etc., from entering, affecting normal operation.

Road Illumination Calculation Formula

Road Illumination Calculation Formula:

E = ΣN * U * K / (S * W)

• E: Average road illumination (units: lx).
• N: Number of light sources.
• U: Utilization factor.
• K: Maintenance factor.
• S: Spacing between poles (units: m).
• W: Road surface width (units: m).

Conclusion

Selecting the appropriate light pole is one of the keys to the success of a solar street light system. When choosing poles, it is essential to comprehensively consider functionality, practicality, economy, safety, and aesthetics to ensure the poles can operate steadily over the long term. Specific indicators such as pole height, wall thickness, corrosion resistance, and wind resistance should be determined based on road types, geographical locations, and meteorological conditions. By making rational selections and designs, the overall performance, lifespan, and cost-effectiveness of the solar street lighting system can be effectively enhanced.

Solar Street Light Height and Distance Spacing Calculation