Street lights, as the city’s night “guardian”, not only relates to pedestrian and vehicle travel safety, but also with energy consumption, light pollution control is closely related. In the street light planning, spacing is a hidden “university question” – spacing is too large, easy to appear lighting blind spot; spacing is too dense, will cause energy waste. This article from the solar street light spacing considerations, the actual planning points and optimization strategy to start, talk about how to through scientific planning and intelligent technology, so that the solar street light is both bright and reasonable, but also cost-effective.
solar street lights
The beam angle of the LED light source is the basis for spacing. Wide beam with 10-12 m poles, a single lamp can cover up to 40-50 meters, so the spacing can be set to 40-50 meters; narrow beam due to light concentration, coverage is small, the spacing needs to be reduced to 20-30 meters, suitable for intersections and other key areas.
Solar panel efficiency is also very critical, high-efficiency panels can store more electricity in areas with short sunshine, allowing the spacing to be appropriately widened by 5-10 meters; low-efficiency panels need to reduce the spacing to make up for the lack of energy storage. Different types of street lights have different functions, and the spacing ranges from 20-60 meters to meet the needs of different scenarios.
Different roads have different requirements on lighting “intensity” and “range”, so the spacing of solar street lights should be adapted to the local conditions. Main roads or highways with high traffic flow and fast speeds require high illumination and long coverage distance, usually using 12-15 meter high poles, with a spacing of 40-50 meters, and more symmetrical arrangement to avoid light dead ends. District roads or secondary roads to pedestrians as the main object of service, moderate illumination can be, light pole height of 8-10 meters, spacing 30-40 meters, not only to ensure safety, but also not due to too dense caused by light pollution. Rural roads or pedestrian street traffic and traffic flow is small, can be used 6-8 meters high lamp poles, spacing 20-30 meters, and even with decorative design, both lighting and aesthetic.
Solar street lights rely on sunlight to generate electricity, while light propagation is susceptible to environmental interference, which will affect the spacing settings. In areas with sufficient sunshine, solar street lights have high charging efficiency and sufficient energy storage, and the spacing can be appropriately relaxed. While in cloudy and rainy, short-light hours in the region, you need to narrow the spacing, or choose a larger capacity of the battery, to avoid insufficient power at night.
Roads on both sides of the trees, buildings will block the sunlight and light propagation, for example, if the street lamps in front of dense trees, not only will block the solar panel sunshine, but also shorten the lighting coverage, this time the need to appropriately raise the height of the lamp post, or narrow the spacing, to ensure that the light can penetrate the blockage.
One of the core advantages of solar street lights is energy saving, and reasonable spacing is the key to avoid “over-illumination”. Traditional street lights may be “over-illuminated” due to their reliance on the power grid, while solar street lights, whose electricity comes from sunlight, need to be more finely tuned – through precise spacing planning, reducing unnecessary lamps and lanterns installation under the premise of guaranteeing the lighting demand, and reducing energy consumption from the Reduce energy consumption at source. In addition, most solar street lights use warm light sources (color temperature ≤3000K), which, together with reasonable spacing, reduces the upward spill of light and the impact on the surrounding ecology and astronomical observation, in line with the “dark sky” environmental protection concept.
One of the major sources of light pollution is the undifferentiated scattering of light, which can be effectively controlled by solar street lights through technical design and spacing optimization. Adopting “full cut-off” LED fixtures, the special reflector design focuses the light on the road surface and reduces upward and sideways light spillage. With reasonable spacing, it can ensure even illumination of the road surface and avoid interference with residents’ windows and night sky. Intelligent solar street light can also detect ambient light through sensors and automatically reduce the brightness in the late night and other traffic hours to further reduce light pollution, for example, in the morning from 2-5 a.m., the brightness will be reduced to 30%, which does not affect the basic lighting, but also reduces the light scattering.
solar street lights
Solar street lights derive their energy from sunlight, so spacing planning must match energy collection and consumption. In areas with sufficient sunshine, the spacing can be increased by optimizing the angle of solar panels to increase power generation. For example, in the 30 ° north latitude area, the panel tilt angle is set to 30-40 °, the power generation is optimal, this time the street light spacing can be widened than the traditional street light 10-15%.
Intelligent dimming technology is an “energy-saving magic weapon”, when the sensor detects no one on the road without a car, the street lamp automatically enters the low-power mode; there are vehicles or pedestrians close to, and then instantly enhance the brightness. A pilot project shows that this dynamic dimming mode reduces the energy consumption of solar street lights by more than 40%, indirectly reducing the number of street lights required and allowing for more flexible spacing planning.
Solar street light spacing planning, but also consider the convenience of late maintenance, after all, “well installed” more to “use for a long time”. The modular design of solar street lights, batteries, LED modules and other components can be replaced individually, reducing the overall replacement cost. When planning the spacing, it can be combined with maintenance routes to avoid the distribution of street lights being too scattered and facilitate centralized maintenance by inspectors.
Intelligent solar street lights with IoT system can upload operation data (e.g. battery power, light source brightness) in real time. When a street lamp has insufficient power, the system will automatically warn the staff to accurately locate the maintenance, without the need for lamp-by-lamp inspection. This “data-based maintenance” model allows street lights that are slightly farther apart to be maintained in a timely manner.
solar street lights
Reasonable installation layout and symmetry design can further optimize the light effect of solar street lights, which indirectly affects the actual role of spacing.
On two-way lanes or wider main roads, symmetrical layout is often used, i.e. street lights are distributed symmetrically on both sides of the road. In this case, the light from both sides of the street lamps can complement each other and reduce the blind spot in the middle area, so the spacing can be kept within the recommended range of 40-50 meters without additional reduction. For example, a symmetrical arrangement of 12-meter high poles will cover 20-25 meters on one side, and when stacked on both sides, will completely cover a 40-50 meter wide roadway with better light uniformity.
In narrow roads or secondary roads, staggered layout is more common, with street lights distributed alternately on both sides of the road. In this case, the coverage of a single lamp needs to be connected to the coverage of the opposite street lamp, and the spacing can be slightly smaller than the symmetrical layout, usually 30-40 meters. For example, 8-meter-high light poles staggered layout, each lamp covers 15-20 meters, staggered to ensure that the road surface without obvious dark areas, while reducing the number of lamps and lanterns than the symmetrical layout by half, more cost-effective.
Rural paths or pedestrian streets and other very narrow roads, mostly using a single-side layout. As only one side of the street lamps, light coverage is limited, the spacing needs to be further reduced to 20-30 meters, and the height of the lamp post to 6-8 meters is appropriate, to avoid the light is too far away, resulting in the edge of the area is too dark. For example, 6 meters high light pole unilateral layout, effective coverage of about 10-15 meters, 20-30 meters spacing to ensure that the light of the two adjacent lamps in the road to form an effective superposition.
The spacing planning of solar street light is not a simple number setting, but a comprehensive balance of lamp characteristics, road demand, environmental conditions and energy saving concept. From the subtle difference in beam angle to the distinctive distinction between road types, from the sunshine conditions of the cloudy and sunny changes to the layout of the design of the clever collocation, each factor is affecting the final spacing choice. Only based on the actual scene, can let the solar street light in the night on the street not only play the role of “guardian”, but also become a model of energy saving and consumption reduction.
