How to Choose a Good Solar Street Light?

In today's era of energy saving and environmental protection, solar street lights are becoming more and more popular due to their significant energy saving features and environmental advantages. Solar street lights can be found everywhere, from the streets of busy cities to the trails of quiet villages.
 

According to relevant market research reports, the global solar street light market has grown at an annual rate of more than 15% over the past five years. However, in the face of a wide range of solar street light products on the market, how to choose a really high quality products? Next, we will provide you with a detailed analysis from several key dimensions.
 

Evaluate Lighting Needs

Solar Street Light Placement Scene

LED solar street lights serve diverse applications. City main roads need high brightness and wide coverage for vehicles and pedestrians, with strict uniformity and brightness maintenance. Sidewalk lighting aims for comfort and avoids glare, especially in tourist areas. Parking lot lighting focuses on clearly illuminating parking spaces and channels to ensure safety. Recreational area lighting combines aesthetics and functionality, like in city parks, using soft, layered light to enhance the night landscape while ensuring safety.
 

Required brightness

Brightness, measured in lumen (lm), is crucial in the field of lighting. The brightness required for lighting varies greatly from area to area, as shown in the table below:
 

Consideration of environmental conditions

Hours of light

The location of the average daily light hours is a key factor, which directly determines the solar street light panel's ability to obtain energy. In light-rich areas, the average daily light hours up to 8-10 hours. These areas are suitable for the use of high-efficiency solar panels with a conversion rate of 20%-25%.

High-efficiency panels can better convert solar energy into electricity to ensure the efficient operation of solar street lights. In areas with relatively insufficient light, where the average daily light hours may only be 4-6 hours, it is necessary to match higher power solar panels or more efficient energy storage devices to ensure that the street lights can work properly even under limited light.
 

Climatic conditions

Rain, snow and fog affect the efficiency of solar panels, which in turn affects energy absorption and light output. Common protection level such as IP65, where “IP” represents the protection level, “6” means completely dust proof, “5” means protection against water spray, can effectively withstand a variety of bad weather, to ensure the long-term stable operation of street lights.

It can effectively withstand all kinds of bad weather and ensure the long-term stable operation of the LED solar street light. In the winter snowy areas, the solar street light should not only be waterproof, but also need to consider the impact of snow on the battery panel coverage.

Some advanced solar street lights are designed with automatic snow removal devices, or through special battery panel tilt angle and surface materials to reduce snow accumulation. In foggy areas, the fog will reduce the light intensity, at this time the solar street light needs to have a higher light conversion efficiency and more stable lighting performance to cope with the low-light environment.
 

Evaluating Solar Street Light Panel Specifications

Panel Efficiency

Monocrystalline and polycrystalline panels are the two common types of solar street lights. Monocrystalline panels typically have efficiencies of 18%-24% and polycrystalline panels have efficiencies of 15%-18%. Due to the higher efficiency of monocrystalline silicon panels, they are more suitable for solar street lights as they can obtain more power under limited light conditions.

In practice, under the same light conditions, a 200-watt monocrystalline silicon panel can store more electricity for solar street lights than the same power polycrystalline silicon panels by 10%-15% a day. This means that in areas with limited light resources, monocrystalline panels can better guarantee the stable power supply of street lights.
 

Power and Durability

The power of a solar panel determines whether it can fully charge the battery on a daily basis. Generally speaking, for street lighting, it is recommended to choose solar panels with a power of 30 - 100 watts. In some densely populated areas with high lighting demand, a 70 - 100 watt panel can be used to ensure sufficient power supply.

At the same time, the panels need to have good weather resistance and long service life to cope with the complex outdoor environment. Usually, the service life of high-quality panels can reach 20 - 25 years. Some high-end solar street lights are equipped with imported panels, which are treated with special technology to maintain stable power generation performance in harsh environments such as high temperature, high humidity and strong ultraviolet rays, which greatly reduces the cost of replacing the panels in the later stage and the maintenance workload.
 

Solar Street Light Battery capacity and type

Battery type

Lithium-ion batteries and lithium iron phosphate batteries are ideal for solar street lights. Lithium-ion batteries have high energy density and discharge efficiency up to 90%-95%, which can provide stable power for street lights. Lithium-ion batteries are mostly used in places with high requirements for brightness and range, such as solar street lights in important urban commercial areas.

Lithium iron phosphate batteries have high safety and long cycle life, and the number of cycle charge/discharge can reach 2000-3000 times, which can effectively reduce the maintenance cost. In some remote areas or places with very high security requirements, such as lighting around flammable and explosive factories, lithium iron phosphate batteries are more advantageous.
 

Battery capacity and life

Battery capacity should be able to meet the power supply requirements of street lights in continuous cloudy days. For example, in cloudy and rainy areas, it is recommended to choose the capacity of the battery to maintain street lighting for 3 - 5 days. In the actual project, if the local continuous cloudy and rainy days are more frequent, the number of battery packs can be increased or a larger capacity single battery can be used to ensure the lighting.

At the same time, the battery life is also an important consideration, the service life of high-quality batteries is at least 5 years, which can reduce the trouble and cost of frequent battery replacement. Some brands of LED solar street lights equipped with high-performance batteries, under normal use conditions, can work stably for 7-8 years, greatly reducing the long-term cost of use.
 

Solar Street Light Fixtures and LED Quality

LED Quality

High quality LED have high luminous flux output and long life. High luminous efficacy LED produce more lumen per watt, improving overall lighting efficiency. For example, high quality LED can produce 150-200 lumen per watt, which can significantly reduce energy consumption compared to ordinary LED.

In some large-scale lighting projects, solar street lights using high-quality LED can consume 20% - 30% less energy than ordinary LED street lights for the same brightness requirement. Moreover, the color rendering index of high quality LED is higher, which can more realistically reproduce the color of objects and improve the lighting effect.
 

Color Temperature

Color temperature is used to describe the color of the light source, the unit is Kelvin (K). Different color temperatures are applied to different scenarios, as follows.

Beam Angle

Beam angle affects light distribution. For open areas, such as squares, large parking lots, it is suitable to use 120°-180° wide beam angle street lamps, which can realize uniform lighting over a large area. Like some of the city's large public squares, the use of wide-beam angle street lights, the entire square can be illuminated, convenient for public recreation.

For sidewalks, trails, 60°-90°narrow beam angle street lights can accurately illuminate a specific path. In some winding mountain trails, narrow-beam angle street lights can accurately illuminate along the road, avoiding wasted light and interference with the surrounding environment.
 

Solar Street Light Control and Intelligent Functions

Automatic Light Control

The automatic light control function enables the street light to turn on and off automatically according to light changes. When night falls, the street light turns on automatically when the light dims to a set threshold; at dawn, the street light turns off automatically when the light brightens.

This feature greatly improves the convenience of use, while avoiding unnecessary energy waste. According to statistics, LED solar street lights with automatic light control function can save about 10%-15% of electricity consumption per year compared with manually controlled street lights, and there is no need for manual operation, which reduces management costs.
 

Human Sensor Function

The human body sensing function adjusts the brightness of the street light by sensing human activities. When there are frequent human activities, the street light keeps full brightness; when there is no activity in the area, the street light automatically reduces the brightness. According to statistics, Intelligent solar street light with human body sensing function can save 30%-50% energy compared with ordinary street light.

In the road lighting of some residential neighborhoods, where there are fewer pedestrians at night, when no one is sensed passing by, the street light automatically reduces its brightness to maintain only the basic lighting needs; when someone passes by, the LED solar street light instantly becomes bright, which not only ensures safety but also saves energy.
 

Remote Monitoring Function

The remote monitoring function allows remote management of the solar street light through the network. The working status of the street light can be monitored in real time, such as battery power, light intensity, fault alarms, etc. Once problems are found, maintenance can be arranged in time. Once problems are found, maintenance can be arranged in time, which greatly improves the efficiency of street light management and reduces maintenance costs.

Intelligent lighting management system in some cities, through remote monitoring, can be unified management of the city's solar street lights. When a street light fails, the system can immediately issue an alarm and locate the fault location, maintenance personnel can quickly go to deal with the failure to minimize the impact of the scope and time.
 

Solar Street Light Durability and Weather Resistance

Sturdy Material

Solar street lights are usually made of aluminum alloy, stainless steel and other sturdy materials. Aluminum alloy has the advantages of light weight, high strength and corrosion resistance. In some coastal areas, due to high humidity and salt content in the air, the corrosiveness of the  solar street light material is strong, aluminum alloy material after special surface treatment, can effectively resist the erosion of the sea breeze, to ensure the long-term stable operation of the street light.

Stainless steel material has excellent anti-rust performance, can effectively resist the erosion of bad weather, to ensure that the street lights in the outdoor environment of long-term stable operation. In some northern cold areas, low winter temperatures and road salt snow, stainless steel solar street light poles can resist salt corrosion, to ensure the structural safety of solar street lights.
 

Waterproof and Protection Grade

Waterproof performance is an important indicator of LED solar street light, IP65 protection grade street light can completely prevent dust from entering, at the same time can effectively resist water spray from all directions, even in heavy rain weather can work normally, to ensure the long-term reliability of the street light.Some high-end solar street lights can even reach IP67 protection level, which can work for a short time underwater at a certain depth, which is especially important for some areas that are prone to water logging or installation locations near water bodies.
 

Solar Street Light Installation and Maintenance

Installation Location Considerations

When installing solar street lights, you need to ensure that the installation location is sunny and unobstructed. In urban areas where there are many tall buildings, the installation should be carefully planned to avoid the street light being blocked by buildings. At the same time, to avoid other light sources around to interfere with the light sensor of the street lamp, affecting the automatic switching function.

When installing solar street lights in some places close to commercial billboards or landscape lights, the installation angle needs to be adjusted or light-shading measures taken to prevent misjudgment. Installation of the light pole should be far away from heat sources, and make sure it is installed on a flat and solid ground. If close to a body of water, you need to ensure that the battery box is always above the water level line to prevent water damage.In some lakeside and riverside landscape lighting projects, a detailed study of water level changes is required before installation to ensure that the solar street lights are not affected even at the highest water level.
 

Maintenance Requirements

Solar street lights are designed to be basically maintenance free, but in some extreme environmental areas, such as sandy, dusty, icy or snowy areas, regular maintenance may be required. Sand, dust, snow or ice will cover the solar panel and reduce the efficiency of power generation, when the panel needs to be cleaned regularly. In dusty areas in the Northwest, the panels need to be cleaned once a month in the spring of each year when the wind and sand are high to ensure the efficiency of power generation.

In areas with frequent rainfall, the tilt angle of the battery board is designed to realize automatic cleaning; however, in areas with little rainfall, the battery board needs to be cleaned manually on a regular basis to ensure that the street lights work properly. In some inland cities with little rainfall, the panels should be cleaned manually once a quarter to remove dust and dirt from the surface.
 

Solar Street Light Warranty and after-sales support

Warranty Coverage

When purchasing solar street lights, be sure to check the warranty terms carefully. A comprehensive warranty should cover the main components of the street light, such as solar panels, batteries, LED lights, etc. The warranty period is usually 3-5 years.During the warranty period, if the product has quality problems, the manufacturer should be responsible for free repair or replacement. Some famous brands of solar street lights provide up to 10 years warranty for solar panels, which greatly increases the confidence of users.
 

After-sales support

It is crucial to choose a manufacturer that provides professional after-sales support. High-quality manufacturers should have a quick response mechanism to answer customers' questions and deal with faults in a timely manner. Setting up a specialized after-sales customer service team and providing a 24 hours service hotline ensures that maintenance personnel can be quickly dispatched to the site to solve the problem upon receipt of a fault report.
 

Conclusion

Choosing a high-quality solar street light requires comprehensive consideration of lighting needs, environmental conditions, panel and battery performance, lamp quality, intelligent features, durability, installation and maintenance, as well as warranty and after-sales service. Only by comprehensively evaluating these factors can you ensure that the solar street light you buy meets your lighting needs while realizing high energy efficiency, stability and durability, providing reliable lighting for your living and working environment.