How Installation Details Affect Solar Street Light Lifespan

Throughout the entire life cycle of solar street lights, the quality of components is undoubtedly the foundation, but the details of installation and maintenance also play a crucial role, and even directly determine whether the system can achieve the expected service life of 10 to 20 years. In reality, many solar street lights experience problems such as premature battery aging and a sudden drop in panel power generation efficiency within just 3 to 5 years of use. Tracing back to the root cause, over 80% of these issues are related to improper installation.
 

Correct installation can maximize the performance of each component and reduce unnecessary wear and tear. Conversely, incorrect installation will accelerate the aging of components, making "long service life" nothing but empty talk and increasing the cost of later maintenance.

Solar Street Lights Installation Site and Location selection

Site selection and positioning are the first steps in the installation of solar street lights, directly determining the power generation capacity of the panels and subsequently affecting the lifespan of the entire system.

Avoid Obstruction

When choosing an installation location, the primary principle is to avoid obstructions. Special attention should be paid here to the "nonlinear impact of partial occlusion". Even if only 10% to 20% of the panel area is shaded by trees or buildings, the overall power generation may still drop by more than 50%.

The Average Annual Sunshine is Abundant

Give priority to avoiding areas with high dust levels, such as those near factories and places with severe road dust. Dust accumulation can reduce the light transmittance of the panels. If not cleaned in time, the annual power generation may decrease by 10% to 15%. At the same time, stay away from areas with dense shade. Even seasonal deciduous trees, their thick branches and leaves in summer can have a significant impact on sunlight.

Seasonal Variations in the Sun's Altitude

In the Northern Hemisphere, the solar altitude Angle is low in winter. If there are tall buildings on the north side of the installation location, there may be prolonged shading in winter. Therefore, when choosing the position, it is necessary to take into account the local solar trajectory to ensure that the panel can receive sufficient sunlight for most of the year.

Site and Location Selection Acceptance

 

Acceptance Project	Acceptance Criteria	Acceptance Results (Qualified/Unqualified)	Remarks
Solar panel sunlight exposure	The solar panels remain unobstructed throughout the year without blockage from trees, buildings, or other objects.		This can be verified using sunlight simulation software.
Annual sunshine duration	The annual average sunshine hours at the installation site meet the design requirements,areas without heavy dust		Refer to data from the local meteorological department
Surrounding environment safety	The surrounding environment must be far from flammable or explosive materials and free from strong electromagnetic interference.

 

The Orientation and Inclination of Solar Panels

The orientation and inclination of solar panels are the core factors affecting power generation. Reasonable setting can significantly increase the annual power generation, reduce the number of deep discharges of the battery, and extend the battery life.

Orientation of Solar Panels

In terms of orientation, in the Northern Hemisphere, solar panels should preferentially face south, while in the Southern Hemisphere, they need to face north. The principle is the same. At the same time, make sure the orientation is unobstructed, especially during the noon period, to avoid buildings, trees and other obstructions affecting sunlight.

Solar Panel Inclination Angle

From the perspective of inclination Angle, it needs to be optimized according to the local latitude and usage requirements. The most ideal tilt Angle is to maximize the total amount of solar radiation received by the panel throughout the year, usually equal to the local latitude or ±10° of the local latitude.

The Fixed Bracket of the Solar Panel

In addition, the mechanical strength of the fixed bracket of the panel should not be ignored either. The support frame must have excellent wind resistance, capable of withstanding the maximum local wind force to prevent the panel from tilting, shifting or even being damaged due to strong winds. The material of the bracket should preferably be galvanized steel or aluminum alloy, which have corrosion resistance and can prevent problems such as rusting and cracking during long-term outdoor use.

Acceptance of the Orientation and Inclination Angle of Solar Panels

 

Acceptance Project	Acceptance Criteria	Acceptance Results (Qualified/Unqualified)	Remarks
Installation Orientation	Facing south in the Northern Hemisphere with a deviation no greater than ±15°; facing true north in the Southern Hemisphere with a deviation no greater than ±15°.		Measured using a compass
Inclination Angle	The inclination angle is within ±10° of the local latitude and meets design requirements.		Measured with an inclinometer
Support Material & Fixing	Support material must be galvanized steel or aluminum alloy, with wind resistance ≥ level 12; firmly fixed.		Check support thickness and bolt tightness

 

Solar Street Lights Pole Height, Light Layout and Beam Design

The height of the light pole, the arrangement of the lights and the design of the light beam not only affect the lighting effect, but also indirectly influence the lifespan of the LED and the battery. Incorrect configuration can cause the components to be in a high-load operating state for a long time.

Height of the Light Pole

The height of the light pole of solar street lights should be reasonably selected according to the lighting scene. For scenarios such as walkways and alleys, the height of the light poles can be set at 3 to 4 meters. For community main roads and rural roads, the height of the light poles can be set at 4 to 6 meters.

Lighting Fixture Arrangement

The arrangement of lighting fixtures should follow the principle of "even coverage and no blind spots", and the spacing is usually 3 to 4 times the height of the light pole. If the spacing is too large, dark areas of illumination will occur. To compensate for the brightness of the dark areas, the power of the LED may be increased, and the battery discharge load may also be raised. If the spacing is too small, it will cause overlapping lighting and waste electricity.

Beam Design

Beam design is also of vital importance, and the appropriate beam Angle should be selected based on the lighting requirements. For walkway lighting, a wide beam Angle (above 120°) is suitable to achieve extensive coverage. The main road lighting is suitable for medium beam angles (60°-120°), which ensures coverage while increasing the central illuminance of the road surface.

Solar Street Lights Foundation and Structural Safety

The safety of the foundation and structure is the prerequisite for the stable operation of solar street lights. Foundation settlement, loose light poles or inadequate rust prevention will trigger a series of chain reactions, leading to premature failure of the equipment.

Select the Appropriate Base Type

For areas with hard soil, independent concrete foundations can be adopted. The depth of the foundation should be no less than 1.2 meters and the diameter no less than 0.6 meters to ensure that it can bear the weight of the light pole and the panel, while also resisting external forces such as strong winds and earthquakes. For areas with soft soil or abundant rainfall, the depth of the foundation should be increased to more than 1.5 meters. If necessary, steel bars can be added to enhance the stability of the foundation and prevent settlement.

Installation of Light Poles

The installation of the light pole must be vertical and firm. After installation, it should be calibrated with a level, and the verticality deviation should not exceed 1°. The connection between the light pole and the foundation should use high-strength bolts. The bolts need to be treated for rust prevention (such as hot-dip galvanizing), and the tightness of the bolts should be checked regularly to avoid loosening after long-term outdoor use.

Rust Prevention Treatment

In addition, rust prevention treatment is the key to structural safety. Metal parts such as light poles and brackets need to be galvanized or coated with anti-corrosion coatings. The thickness of the coating should comply with industry standards to prevent rusting caused by rain and moisture erosion. In areas with high salt spray such as coastal regions, components made of 316 stainless steel should also be selected to enhance corrosion resistance. ,

Foundation and Structural Safety Acceptance

 

Acceptance Project	Acceptance Criteria	Acceptance Results (Qualified/Unqualified)	Remarks
Concrete foundation depth	The depth of the concrete foundation shall be ≥1.2 meters (≥1.5 meters for soft soil)		measured on site
Base material concrete strength	The strength grade of the base material concrete is ≥C25, with no cracks or hollowing.		Visual inspection should be conducted, and strength testing should be carried out if necessary
Light pole verticality	The verticality of the light pole has a deviation of no more than 1°, with no inclination or settlement.		Measured with a level
Anti-corrosion treatment of metal parts	The metal parts such as the light poles, brackets and bolts are all treated with galvanization or anti-corrosion coating for rust prevention.		visual inspect

 

Electrical Wiring, Grounding and Lightning/Surge Protection

Electrical wiring, grounding and lightning/surge protection are at the core of ensuring the electrical safety of solar street lights. Standardized operation can prevent lightning strikes and voltage spikes from damaging the controller and battery, which is the key to extending the system's lifespan.

Electrical Wiring

In terms of electrical wiring, cables with strong weather resistance should be used. RVVY or RVVP series outdoor dedicated cables are preferred, which have waterproof, sun-proof and high and low-temperature resistance properties. The cross-sectional area of the cable should be selected according to the size of the current to avoid overheating of the line due to a too small cross-sectional area, which may affect the transmission efficiency and even cause a fire.
 

When wiring, pipes should be run through for protection to prevent the cables from being exposed and damaged by sun exposure, rain, animal bites, etc. Waterproof terminal blocks should be used at the joints and properly sealed to prevent rainwater from seeping in and causing short circuits. Meanwhile, the cable routing should be reasonable to avoid entanglement and pulling, and reduce the stress at the joints.

Grounding Protection

Grounding protection is indispensable. A dedicated grounding electrode should be set up, and the grounding resistance should be ≤4Ω. Metal components such as solar panel brackets, light poles, controller housings, and battery boxes all need to be reliably grounded to form a complete grounding system. Grounding can conduct lightning currents, static electricity, etc. into the ground, preventing the accumulation of charges and damage to electrical components.

Surge Protection

Surge protection (SPD) cannot be ignored either. Appropriate surge protectors need to be installed at the input end of the solar panel and the power supply end of the controller. Surge protectors can absorb voltage spikes caused by lightning strikes and grid fluctuations, protecting subsequent electrical equipment.

Acceptance of Grounding and Surge Protection

 

Acceptance Project	Acceptance Criteria	Acceptance Results (Qualified / Unqualified)	Remarks
Ground Resistance	Ground resistance ≤ 4Ω		measured using a ground resistance tester.
Grounding Connections	The grounding connection panel bracket, light pole, controller housing, battery box, and other metal parts must be reliably grounded. The cross-sectional area of the grounding cable must be ≥ 16 mm².		Check the firmness of the wiring and cable specifications.
Surge Protection	Surge protectors must be installed at both the input end of the surge protector panel and the power input of the controller. The surge protector must have a current-carrying capacity ≥ 20 kA and a fault-indication function.		Check the surge protector model, installation position, and perform testing.

 

Battery Installation Location, Ventilation and Thermal Management

Batteries are extremely sensitive to temperature. The installation position, ventilation and thermal management design directly affect the battery life. Especially in extreme temperature environments, a reasonable design can significantly extend the battery's cycle life.

Battery Installation Position

From the perspective of installation location, batteries should be avoided from being installed in areas with high temperatures and direct sunlight or extremely low temperatures and severe cold. The battery box should be installed on the shady side of the light pole or shading measures should be taken to avoid direct sunlight. Meanwhile, in cold regions, insulation treatment can be carried out on the battery box, such as adding insulation cotton, to prevent the influence of low temperatures.

Battery Ventilation Design

Ventilation design is also of vital importance. The battery box should be equipped with ventilation holes to ensure air circulation. The positions of the ventilation holes should be reasonable to prevent rainwater and dust from entering. For LiFePO4 batteries, although they generate less heat, good ventilation can still maintain a stable working temperature and extend their lifespan.

Installation of Different Types of Batteries

LiFePO4 batteries have relatively strong adaptability to temperature, but they still need to avoid being in a high-temperature environment above 50℃ for a long time. When installing, a vertical battery box can be chosen to facilitate heat dissipation.

Sealed lead-acid batteries are more sensitive to temperature and may produce a small amount of hydrogen. The battery box should have better ventilation and avoid being installed in a closed space to prevent hydrogen accumulation and potential safety hazards.

Battery Box and Battery Acceptance

 

Acceptance Project	Acceptance Criteria	Acceptance Results (Qualified/Unqualified)	Remarks
Battery box installation position	The battery box should be installed on the shady side of the light pole, at least 1.5 meters above the ground, free from direct sunlight and water accumulation.		On-site inspection should be conducted.
Battery box ventilation	The battery box is equipped with ventilation holes for good ventilation. In high-temperature areas, cooling fans are provided.		Check the number of ventilation holes and the operation of the fans.
Battery status	The battery shows no bulging, leakage, or corrosion. The voltage and capacity meet the design requirements.		Measure the battery voltage and capacity and conduct an appearance inspection.
Temperature control measures	In cold regions, the battery box has insulation measures; in high-temperature regions, there are heat dissipation measures.		Check the insulation cotton, cooling fans, etc.

 

Controller/Charge and Discharge Logic and Layout

The controller is the "brain" of a solar street light, responsible for charging and discharging management. Correct charging and discharging logic Settings and standardized wiring can effectively extend the battery life and prevent component damage caused by improper control.

Reasonably Limit the Depth of Discharge

The depth of discharge requirements for different types of batteries vary. For LiFePO4 batteries, it is recommended that the depth of discharge not exceed 80%, and for sealed lead-acid batteries, it should not exceed 50%. If the depth of discharge is too large, it will accelerate the wear of the battery plates and shorten the cycle life. The controller needs to preset an appropriate discharge termination voltage based on the battery type. When the battery voltage drops to the termination voltage, the load will be automatically cut off and the discharge will stop.

Anti-reverse Connection Design

The controller must have a reverse connection protection function for positive and negative poles to prevent the positive and negative poles of the cable from being reversed during installation, which may cause damage to the controller and battery. In addition, overload protection and short-circuit protection need to be set up. When the LED load is overloaded or the line is short-circuited, the controller can promptly cut off the circuit to ensure the safety of the equipment.

Controller Layout

In terms of controller layout, it should be installed in a dry and well-ventilated location, avoiding damp and high-temperature environments. The wiring of the controller with the battery, panel and LED should be standardized. The cross-sectional area of the cables should match. The terminal blocks should be firmly tightened to avoid poor contact causing overheating. At the same time, waterproof sealing treatment should be done well at the connection points to prevent rainwater from seeping in and causing short circuits.

Solar Street Light Protection and Anti-fouling

Protection and anti-fouling are the guarantees for the long-term stable operation of solar street lights. Appropriate IP ratings, sealing measures, and regular cleaning can reduce the impact of the external environment on the components and extend the system's lifespan.

Choose the Appropriate IP Rating

Each component of solar street lights should be selected with the corresponding IP rating based on the installation environment. The IP rating of the panel and the light housing should be ≥IP65, which can effectively prevent dust from entering and rainwater from soaking. The IP rating of the controller and battery box should be ≥IP67, featuring stronger waterproof performance. Especially in rainy and humid areas, a higher IP rating can prevent internal components from getting damp and damaged.

Sealing and Waterproofing

In addition to the IP rating of the component itself, the sealing treatment during the installation process is also crucial. The connection points between the panel and the bracket, the connection points between the light and the light pole, the cable joints, etc., all need to be sealed with waterproof glue, sealing rings, etc., to prevent rainwater from seeping in.

Clean the Solar Panels Regularly

In terms of pollution prevention, the key point is to clean the solar panels regularly. The frequency of cleaning should be determined based on the local environment. Generally, it is recommended to clean once every 3 to 6 months. In areas with high dust levels and frequent rainfall (where dirt tends to accumulate after rain), the cleaning frequency can be shortened to once every 1 to 2 months.

In addition, the interior of the lights also needs to be inspected regularly to prevent insects and dust from entering, which may affect the heat dissipation and luminous efficiency of the leds. If dirt is found inside the lights, it should be cleaned up in time and the sealing condition should be checked to prevent dirt from entering again.

Common Installation Mistakes of Solar Street Lights

Error 1: There is Obstruction in the Solar Panels

Fault mechanism: Partial obstruction of the panel will cause a "hot spot effect", leading to local overheating, burning out the panel, and at the same time, the overall power generation will drop significantly, the battery will be insufficiently charged, and frequent deep discharges will occur, shortening its lifespan.
 

Preventive measures: Conduct a detailed site investigation before installation to ensure that the panel installation position is unobstructed throughout the year. If there is a small amount of obstruction due to certain conditions, a hot spot protection device needs to be installed on the panel. Regularly inspect the surrounding environment and promptly remove any newly emerged obstructions.

Error 2: Surge Protection Devices are not Installed

Fault mechanism: During thunderstorms, lightning generates induced overvoltage. Without surge protection, the controller and battery electronic components may be damaged, leading to equipment damage or even fire.
 

Preventive measures: Regardless of the frequency of local thunderstorms, appropriate surge protectors must be installed at the panel input end and the controller power end. Choose a controller with lightning protection function for dual protection. Regularly test the performance of surge protectors and replace them in a timely manner if any faults occur.

Error 3: The Foundation Has Not Been Reinforced and the Light Pole is Loose

Failure mechanism: If the foundation is not reinforced, it will cause the light pole to settle and tilt, the support to be unevenly stressed, and the position of the panel and the light to shift, affecting the reception of sunlight. Loose light poles will sway under the influence of wind, causing cable stretching, loose joints, short circuits, and even the collapse of the light poles, resulting in safety accidents.
 

Preventive measures: Ensure the depth and material of the foundation in accordance with the design during construction. Calibrate the verticality of the light pole with a level and tighten the bolts. Conduct a wind resistance test after installation; Regularly inspect and reinforce.

Error 4: Exposed Cables and Improper Handling of Joints

Fault mechanism: When cables are exposed, they will be subject to sun exposure, rain, and animal gnawing, which can cause the insulation layer to age and be damaged, leading to short circuits. The joint has not been treated with waterproof sealing. Rainwater seeping in will cause poor contact, oxidation, increase the resistance of the line, heat up and burn out the joint, and even cause a fire.
 

Preventive measures: The cables are protected by outdoor-specific weather-resistant pipes. The joints are sealed with waterproof terminal blocks and junction boxes. Regularly inspect and replace damaged and aged cables.

Error 5: The Battery is Placed in A Direct Sunlight Area without Ventilation for Heat Dissipation

Fault mechanism: At high temperatures, the internal reactions of the battery accelerate, the electrolyte decomposes, the plates corrode, and the lifespan shortens. In a closed environment, heat cannot dissipate, creating a high-temperature cycle, which may lead to battery swelling, leakage or even explosion.
 

Preventive measures: Install the battery box on the shady side of the light pole or provide shade. Set ventilation holes; In high-temperature areas, add insulation layers or cooling fans to the battery box. Choose high-temperature resistant batteries (such as LiFePO4 batteries).

Error 6: Incorrect Wiring of the Controller

Fault mechanism: Incorrect wiring burns out the electronic components of the controller, making it impossible to manage charging and discharging. It also causes the battery to fail to charge but be discharged instead, resulting in abnormal power supply to the LED.
 

Preventive measures: Read the controller manual before installation to clarify the terminal functions. Mark the wiring to prevent confusion. After wiring, power on for testing to confirm that the controller, battery and LED are normal before putting it into use.

Error 7: The Inclination Angle of the Solar Panel is Unreasonable

Fault mechanism: Unreasonable tilt Angle reduces annual power generation, insufficient battery charging shortens lifespan due to frequent deep discharge to meet lighting requirements. At the same time, when the LED operates at non-rated voltage, the light attenuation accelerates.
 

Preventive measures: Determine the optimal tilt Angle based on the local latitude. For power generation in winter, the tilt Angle can be increased. Before installation, use professional software to simulate and select the optimal inclination Angle. Regularly check and adjust the offset inclination Angle.

Error 8: No grounding protection was done or the grounding was poor

Fault mechanism: No grounding or poor grounding, lightning current and static electricity cannot be conducted into the ground, breaking down the insulation layer of the equipment and damaging it. It may also cause electric shock to personnel.
 

Preventive measures: Set up a dedicated grounding electrode to ensure that the grounding resistance is ≤4Ω; All metal parts are reliably grounded. Regularly test the grounding resistance and rectify it in a timely manner if it exceeds the standard.

Installation details play a decisive role in the service life of solar street lights. From site selection, panel orientation and inclination Angle, to the foundation structure, electrical wiring, grounding and lightning protection, and then to battery temperature control, protection and anti-pollution, the installation quality of each link directly affects the power generation, battery cycle times, and thus determines the lifespan of the entire system. Proper installation can enable the system to have an expected lifespan of 10 to 20 years, while incorrect installation may shorten the lifespan by 30% to 50% and increase a significant amount of maintenance costs.