What Is the Most Suitable Spacing for 6-Meter Solar Street Lights?

Based on industry experience and practical installation data, the most suitable spacing for 6-meter solar street lights generally falls between 20 meters and 30 meters. This range is derived from the balance of three core needs: ensuring uniform lighting without dark areas, maximizing energy efficiency of solar modules, and controlling overall installation costs. Specifically, the spacing can be adjusted within this range according to different application scenarios, which is the key to achieving optimal lighting effects.

For most rural roads and residential secondary roads, a spacing of 25-30 meters is preferred. These roads usually have a width of less than 5 meters, with low pedestrian and vehicle flow, and relatively low requirements for lighting intensity (average illuminance of 5-10 lux is sufficient). Adopting this spacing can avoid excessive overlap of light, reduce energy waste, and at the same time ensure that there are no obvious shadow areas between two lights. For scenarios with higher lighting requirements, such as community main roads, park main paths, or school peripheral roads, the spacing should be narrowed to 20-25 meters to improve lighting uniformity and brightness, meeting the safety needs of pedestrians and vehicles at night.

1. Road Width and Layout

   Road width is the most direct factor affecting spacing. According to the empirical formula for lighting design, the height of the lamp pole (H) should be roughly 0.5 times the road width (W) plus 1.5 meters (H = 0.5*W + 1.5), which is especially applicable to 6-meter lamp poles. For roads with a width of 3-5 meters (such as rural dirt roads and residential alleys), the 25-30 meter spacing is fully applicable because the light of 6-meter lamp poles can cover the entire road surface through unilateral installation. For roads with a width of 6-8 meters (such as community main roads and small-town secondary roads), it is recommended to adopt bilateral staggered installation, and the spacing can be maintained at 20-25 meters to ensure that the middle area of the road is fully covered without dark spots.

   In addition, for curved roads or road intersections, the spacing should be reduced by about 20% compared with straight roads, and an additional street light should be installed at the corner if necessary to eliminate lighting dead angles caused by road turns.

2. Lighting Requirements and Standards

   Different application scenarios have different requirements for lighting intensity and uniformity, which directly determine the spacing. According to international and domestic lighting standards, the average illuminance and uniformity requirements vary significantly between different road types:

   • Rural roads and pedestrian paths: Average illuminance of 5-10 lux, uniformity ≥ 0.3. The 25-30 meter spacing can fully meet this requirement, and unilateral installation is sufficient.
   • Community main roads and secondary urban roads: Average illuminance of 10-15 lux, uniformity ≥ 0.4. It is necessary to narrow the spacing to 20-25 meters, and bilateral installation is recommended for wider roads.
   • Scenic spots and parks: The lighting requirement is moderate, focusing on aesthetic effect. The spacing can be 22-28 meters, and staggered installation can create a soft and comfortable lighting atmosphere without glare.

   It should be noted that the height-to-spacing ratio should not exceed 3.5 to ensure adequate light overlap and meet uniformity standards. For 6-meter lamp poles, this means the maximum spacing should not exceed 21 meters if strict uniformity is required, but this can be appropriately relaxed in scenarios with low lighting requirements.

3. Performance of Solar Street Light Fixtures

   The performance of the lamp itself, including LED power, luminous efficiency, light distribution curve, and solar module capacity, also affects the spacing setting.

   LED power and luminous efficiency: Generally, 6-meter solar street lights are equipped with 30-60W LED lamps. Lamps with higher power (50-60W) and higher luminous efficiency (above 130lm/W) have a larger irradiation range and stronger light penetration, so the spacing can be appropriately increased by 2-3 meters. For 30-40W lamps with lower luminous efficiency, the spacing needs to be narrowed by 3-5 meters to compensate for the insufficient light intensity.

   Light distribution curve: Lamps with a batwing light distribution curve (light diffuses to both sides) have more uniform coverage, which is suitable for wide roads and can increase the spacing appropriately. Lamps with a narrow light distribution curve (light is concentrated) have a small irradiation range, so the spacing must be narrowed to avoid dark areas.

   Solar module capacity: If the solar module has a large capacity and the battery has strong endurance, the lamp can work at full power for a long time, and the spacing can be slightly wider. On the contrary, in areas with insufficient sunlight, it is necessary to narrow the spacing to ensure the overall lighting effect.

4. Installation Environment

   The on-site installation environment also has an important impact on the spacing. In open areas without obstacles (such as open rural roads and square peripheries), the light can spread unobstructed, and the spacing can be set at the upper limit of the recommended range (28-30 meters). In areas with many obstacles (such as roads with dense trees, buildings on both sides), the light will be blocked, resulting in reduced effective coverage. At this time, the spacing needs to be narrowed to 20-23 meters, or the installation position of the lamp pole should be adjusted to avoid obstacles blocking the light.

   In addition, in areas with strong wind (above level 12), the stability of the 6-meter lamp pole should be considered. Although the spacing itself is not directly affected, the installation density should be reasonably controlled to avoid excessive wind resistance caused by too many lamp poles, which requires balancing the spacing and the stability of the lamp pole structure.

• Pilot installation: For large-scale projects, it is recommended to install 2-3 lamp poles first according to the designed spacing, test the lighting effect at night (using an illuminance meter to detect the average illuminance and uniformity), and adjust the spacing appropriately before formal installation.
• Unilateral vs. bilateral installation: For roads with a width of less than 5 meters, unilateral installation is more cost-effective; for roads with a width of more than 6 meters, bilateral staggered installation is preferred, which can improve lighting uniformity and reduce the number of lamp poles compared with bilateral symmetrical installation.
• Consider maintenance: When setting the spacing, avoid installing lamp poles in areas that are difficult to maintain (such as wetlands, steep slopes), and ensure that there is enough space between lamp poles for maintenance operations.

• Blindly increasing spacing to save costs: This will lead to obvious dark areas between lamp poles, affecting pedestrian and vehicle safety, and even increasing potential safety hazards such as theft and accidents.
• Blindly narrowing spacing: Excessively dense spacing will cause overlapping light, waste solar energy and electric energy, and increase installation and maintenance costs. At the same time, it may cause glare, affecting the visual comfort of pedestrians and drivers.
• Ignoring the matching of lamp performance and spacing: Using low-power lamps with wide spacing will result in insufficient lighting intensity, while using high-power lamps with narrow spacing will cause energy waste. The two need to be matched reasonably.

In summary, the most suitable spacing for 6-meter solar street lights is not a fixed value but a flexible range of 20-30 meters, which needs to be adjusted according to road width, lighting requirements, lamp performance, and installation environment. For most rural roads and residential secondary roads, 25-30 meters is the optimal choice, balancing effect and cost; for scenarios with higher lighting requirements or more obstacles, 20-25 meters is more appropriate. By comprehensively considering the above factors and following practical installation tips, you can ensure that 6-meter solar street lights achieve the best lighting effect, while maximizing energy saving and cost reduction.

Whether you are a project planner, installer, or property manager, mastering the spacing principle of 6-meter solar street lights can help you avoid common mistakes and create a safe, comfortable, and energy-saving outdoor lighting environment.