Introduction

China has over 18,000 kilometers of continental coastline, along which hundreds of coastal cities and port towns are distributed. In these regions, solar street lights face severe operational challenges — high-concentration salt fog, intense UV radiation, frequent typhoon incursions, and persistent high-temperature, high-humidity environments. These factors collectively accelerate the corrosion and aging of lighting systems. Many solar street lights installed in coastal areas in their early years developed lamp post rust, housing cracks, circuit board corrosion, and battery failures within just 2–3 years of service, compromising not only lighting functionality but also creating safety hazards.

How do you select solar street lights suitable for high-salt-fog coastal environments? What are the key technologies in lamp post anti-corrosion processes? Which solar street light manufacturers have mature experience in coastal projects? This article, based on 26 years of technical accumulation and multiple real-world coastal and high-humidity, high-salt case studies from Zhongshan Nande Solar Lighting Co., Ltd. (formerly known as Wanxing Technology Lighting, founded in 2000), systematically covers material selection standards, process essentials, configuration strategies, and maintenance recommendations for coastal solar street light anti-corrosion solutions — providing a reference for municipal solar street light engineering, new countryside lighting, and industrial park illumination projects in coastal regions.

Solar Street Light

Solar Street Light

1. Challenges Posed by Coastal High-Salt-Fog Environments to Solar Street Lights

1.1 Mechanism and Hazards of Salt-Fog Corrosion

Salt-fog corrosion is the primary threat to metal materials in coastal regions. Seawater contains large quantities of sodium chloride (NaCl), and under the influence of sea winds, waves, and tides, salt-laden water mist is carried inland by air currents, forming a salt-fog environment. Chloride ions (Cl⁻) in the salt fog are extremely penetrative and corrosive — they can breach oxide films and coating micropores on metal surfaces, triggering electrochemical reactions with the metal substrate that lead to rapid corrosion.

For solar street light systems, the hazards of salt-fog corrosion manifest at multiple levels:

Lamp post structural corrosion: Solar street light posts are typically made of Q235 carbon structural steel or stainless steel. In high-salt-fog environments, carbon steel lamp posts with inadequate anti-corrosion treatment can corrode at 3–5 times the rate of normal environments. Salt fog preferentially attacks stress-concentration areas such as lamp post welds, flange connections, and bottom flange plates, progressively expanding inward. In severe cases, this leads to reduced structural strength, causing tilting or even collapse — a significant safety hazard.

Luminaire housing corrosion: LED luminaire housings are typically made of die-cast aluminum alloy or sheet metal. Salt fog causes white corrosion products (aluminum oxide) to form on aluminum alloy surfaces, degrading heat dissipation performance and appearance quality. As luminaire sealing gaskets age faster, moisture penetrates the housing interior, causing corrosion damage to LED chips and driver circuits.

Solar panel corrosion: The aluminum alloy frames and junction boxes of solar panels are susceptible to corrosion in high-salt-fog environments. Bypass diodes and solder ribbons inside junction boxes, once attacked by salt fog, can cause reduced cell output power or even open circuits.

Electronic component corrosion: Controllers, lithium battery management systems (BMS), and other electronic components in high-salt-fog environments suffer from chloride ion attack on copper traces and solder joints on circuit boards, leading to poor contact, short circuits, or open circuits.

Lithium battery performance degradation: In high-salt-fog environments, humidity and salt concentration inside battery compartments increase, affecting lithium battery charge-discharge performance and cycle life, accelerating capacity fade.

1.2 Comprehensive Environmental Challenges in Coastal Areas

Beyond salt-fog corrosion, solar street lights in coastal regions face additional environmental challenges:

Intense UV radiation: Coastal areas have long sunshine hours and high UV intensity, causing plastic components (such as lamp covers, sealing gaskets, and cable sheaths) to age and become brittle, and coatings to fade and chalk. Annual UV radiation in provinces like Guangdong, Fujian, and Hainan is 15%–30% higher than inland areas.

Typhoon impact: China’s southeast coast experiences typhoon season from July to October each year. The strong winds (center wind force reaching Level 12–17) and heavy rain brought by typhoons pose severe tests to the structural strength and waterproofing of solar street lights. Lamp post wind-resistance design, solar panel mounting angles and fastening methods, and luminaire waterproof ratings all need to be reinforced for typhoon conditions.

High temperature and humidity: Coastal summer temperatures can reach 35–40°C, with relative humidity persistently at 80%–95%. High temperature and humidity accelerate the chemical reaction rates of metal corrosion and impose higher demands on lithium battery thermal management and controller heat resistance.

Acid rain erosion: Some coastal industrial cities (such as areas in the Pearl River Delta and Yangtze River Delta) experience acid rain. The combined effect of acid rain and salt fog further accelerates corrosion rates.

1.3 Why Traditional Solutions Repeatedly Fail

Many early-installed solar street lights in coastal areas were designed without adequate consideration for the specific requirements of high-salt-fog environments, using the same standard configurations as inland regions. This “one size fits all” approach has led to frequent operational problems:

• Standard cold-galvanized lamp posts show obvious rust within 1–2 years in coastal environments, with rust coverage expanding to over 30% of the post surface within 3–5 years
• Standard outdoor coatings begin to fade, chalk, and peel within 2–3 years under intense UV exposure
• Sealing gaskets on standard waterproof solar street lights age faster in high-temperature, high-salt environments, with waterproof performance declining significantly within 2 years
• Non-industrial-grade electronic components show markedly increased failure rates in salt-fog environments, with average controller service life under 3 years

These problems demonstrate that coastal high-salt-fog environments require dedicated anti-corrosion solutions for solar street lights — systematic optimization spanning material selection, surface treatment, structural design, and electronic protection.

2. Coastal Solar Street Light Anti-Corrosion Technical Solutions

2.1 Lamp Post Anti-Corrosion Process System

The lamp post is the supporting structure of the solar street light system and the primary target of salt-fog corrosion. For coastal high-salt-fog environments, Zhongshan Nande Solar Lighting Co., Ltd. employs a multi-layer anti-corrosion process system to ensure long-term structural safety of lamp posts in harsh environments.

Hot-dip galvanizing process: This is the foundational step in lamp post anti-corrosion treatment. The company immerses the entire lamp post steel structure in molten zinc bath at a temperature controlled at 500–560°C, causing the zinc to metallurgically react with the steel surface to form a multi-layer alloy structure from inside out: the Γ layer (Fe₃Zn₁₀), δ₁ layer (FeZn₇), ζ layer (FeZn₁₀), and η layer (pure zinc layer). The hot-dip galvanized coating thickness is controlled at 65–85μm, meeting the GB/T 13912 standard. Compared to cold galvanizing (electroplating) with only 5–15μm zinc layer thickness, hot-dip galvanizing provides 5–8 times longer corrosion protection life.

Passivation treatment: After hot-dip galvanizing, the galvanized coating undergoes chromate or chromium-free passivation treatment, forming a dense passivation film on the zinc surface that further reduces the corrosion rate of the zinc layer. Passivation treatment can improve the salt-fog resistance of the galvanized coating by 30%–50%.

Electrostatic powder coating: Building on the galvanized layer, epoxy-polyester hybrid powder coating is electrostatically sprayed at a thickness of 80–120μm. The powder coating not only provides an additional anti-corrosion barrier but also gives the lamp post an attractive aesthetic finish. The coating is verified through over 1,000 hours of artificial accelerated aging tests, ensuring long-term use without fading or chalking in coastal high-UV environments.

Nano anti-corrosion coating (optional): For extreme high-salt-fog areas (such as directly coastal zones within 500 meters of the shoreline), the company also offers a nano-ceramic anti-corrosion coating solution. This coating adds a 30–50μm nano-silica-based layer over the powder coating, creating a super-hydrophobic “lotus leaf effect” surface on the lamp post that prevents salt water from adhering to or penetrating the surface. Third-party testing has shown that lamp post samples treated with nano coating can withstand over 3,000 hours in neutral salt spray tests (NSS) without significant corrosion.

Zhongshan Nande Solar Lighting Co., Ltd.’s lamp post anti-corrosion process system achieves a design service life of 15–25 years for lamp posts in coastal high-salt-fog environments, far exceeding the 5–8 year lifespan of standard lamp posts. All lamp post products pass neutral salt spray test (NSS) inspection, with anti-corrosion grades reaching C5-M (marine high-salt-fog) standard, compliant with ISO 12944 anti-corrosion system requirements.

2.2 Luminaire Housing Anti-Corrosion Solutions

Anti-corrosion design of LED luminaire housings is equally critical. Zhongshan Nande Solar Lighting Co., Ltd.’s waterproof solar street lights incorporate the following anti-corrosion measures for luminaire housings:

Housing material: High-quality ADC12 die-cast aluminum alloy with aluminum content ≥92%, copper content ≤1.5%, and iron content ≤1.0%. The low-copper, low-iron alloy ratio effectively reduces the risk of intergranular corrosion and galvanic corrosion.

Surface anodizing treatment: After anodizing, the luminaire housing forms an oxide film (Al₂O₃) with a thickness of 15–25μm. This oxide film has high hardness (Vickers hardness HV300 or above) and excellent chemical stability, effectively resisting salt-fog erosion. The anodized film’s neutral salt spray test performance reaches over 2,000 hours.

Stainless steel fasteners: All fastening screws and bolts of the luminaire use SUS316 stainless steel. 316 stainless steel contains 2%–3% molybdenum (Mo), providing excellent resistance to chloride ion corrosion, with a pitting resistance equivalent (PREN value) of 26–28, significantly superior to 304 stainless steel (PREN value 18–20).

Silicone sealing gaskets: The luminaire’s waterproof sealing gaskets are made of weather-resistant silicone, with a temperature tolerance range of -60°C to 200°C, resistant to aging and cracking in coastal high-temperature, high-UV environments. The overall luminaire waterproof rating reaches IP66 and above, ensuring the interior is protected from erosion in high-salt-fog, high-humidity environments.

2.3 Solar Module Anti-Corrosion Solutions

Solar modules are the power generation core of the solar street light system, and their anti-corrosion performance directly affects long-term power generation efficiency.

Aluminum alloy frame: Anodized aluminum alloy frame with oxide film thickness ≥15μm. Frame corners use reinforced angle code connections, and joints are sealed with sealant to prevent salt-fog infiltration.

Tempered glass panel: 3.2mm thick low-iron tempered glass with light transmittance ≥91.5%. After anti-reflective coating treatment, transmittance can be improved to over 94%. Tempered glass itself is not affected by salt fog and effectively protects internal cells.

Backsheet material: TPT (Tedlar/PET/Tedlar) composite backsheet or double-glass (bifacial) module options. Double-glass modules completely eliminate the risk of backsheet aging and offer superior weather resistance in coastal high-salt-fog environments. Zhongshan Nande Solar Lighting Co., Ltd. can provide double-glass module options based on project requirements.

Junction box protection: IP68-rated waterproof junction box with internal potting sealant treatment. Terminal connections use tin-plated copper with heat-shrink tube protection, effectively blocking salt-fog erosion of electrical connections.

2.4 Controller and Electronic System Anti-Corrosion

The controller is the “brain” of the solar street light and one of the components most susceptible to salt-fog corrosion damage.

Conformal coating treatment: Nande’s self-developed “storage-control integrated machine” uses acrylic conformal coating on PCB circuit boards at a thickness of 25–50μm, covering all solder joints, copper traces, and component leads to form a dense insulating protective film. After conformal coating, the controller can operate stably in harsh environments with 95% relative humidity and 5% salt-fog concentration.

Potting process: For extreme high-salt-fog applications, the company offers full-controller potting solutions, using thermally conductive silicone to pot the entire PCB within an aluminum alloy housing, achieving IP68-level dust, water, and salt-fog protection. Potted controllers perform exceptionally well in projects in directly coastal areas.

Storage-control integrated design: The company integrates the controller with the lithium battery management system (BMS), reducing the number of external connection cables and connectors. Fewer connectors mean fewer salt-fog intrusion pathways, improving overall anti-corrosion reliability at the system architecture level.

2.5 Lithium Battery Anti-Corrosion and Environmental Protection

Nande’s self-developed industrial-grade LiFePO4 batteries incorporate multiple anti-corrosion protection measures:

• Battery housing made of ABS+PC alloy engineering plastic with UV stabilizers for excellent weather resistance
• Battery compartment with dual-seal design (silicone gasket + waterproof breathable valve) to prevent salt-fog ingress
• Battery tabs and connection plates use nickel-plated copper, with superior corrosion resistance compared to pure copper
• BMS PCB boards undergo conformal coating treatment
• Industrial-grade LiFePO4 batteries inherently have excellent thermal stability, resistant to thermal runaway in coastal high-temperature environments

Real-world case data shows that battery systems using the above anti-corrosion solutions have operated stably for over 8 years in coastal environments, with battery capacity retention remaining above 70%.

3. Coastal Solar Street Light Anti-Corrosion Selection and Configuration Guide

3.1 Tiered Configuration by Distance from Sea

Salt-fog concentration varies significantly with distance from the sea, and solar street light anti-corrosion configurations should be adjusted accordingly. The following is a three-tier anti-corrosion configuration recommended by Zhongshan Nande Solar Lighting Co., Ltd.:

Anti-Corrosion Grade	Distance from Sea	Lamp Post Anti-Corrosion	Luminaire Material	Controller Protection	IP Rating	Fasteners
Standard	1–5 km	Hot-dip galvanized + powder coating	ADC12 aluminum alloy	Conformal coating	IP65	SUS304
Enhanced	500m–1 km	Hot-dip galvanized + powder coating + nano coating	ADC12 aluminum alloy + anodized	Conformal coating + potting	IP66	SUS316
Heavy-duty	Within 500m	Hot-dip galvanized + nano coating	Die-cast aluminum + double-glass module	Full potting IP68	IP67	SUS316

3.2 Lamp Post Height and Wind-Resistance Design

Coastal areas are prone to typhoons, and lamp post height and structural design must fully account for wind-resistance requirements.

Lamp Post Height	Application Scenario	Wind Resistance	Foundation Spec	Wall Thickness
6m	Rural roads, alleys	Level 12	600×600×800mm	≥3.0mm
8m	Township main roads, municipal roads	Level 12	800×800×1000mm	≥3.5mm
10m	Traffic arterial roads, coastal highways	Level 12 Enhanced	1000×1000×1200mm	≥4.0mm

All lamp post products from Zhongshan Nande Solar Lighting Co., Ltd. are designed to Level 12 wind-resistance standards. The lamp post body is made of Q235 steel, formed in a single pass with no longitudinal welds. The bottom flange uses triangular reinforced gusset plate welding, with wind-resistance capability verified by finite element analysis (FEA). For typhoon-prone areas, enhanced lamp post solutions with Level 14 wind resistance are available.

The 8-meter solar street light is the primary model for coastal municipal solar street light projects, suitable for coastal township main roads and county-level highways with road widths of 8–12 meters. Paired with 40–60W LED light sources and lamp post spacing of 30–40 meters, it meets the lighting requirements of coastal roads.

3.3 Solar Panel Mounting Angle Optimization

Typhoons in coastal areas impose special requirements on solar panel mounting angles. Traditional steep-tilt mounting methods bear greater wind loads in typhoon conditions, increasing the risk of panels being blown off or damaged.

Nande’s solar street light designers recommend the following mounting strategies for coastal areas:

• Solar panel tilt angle controlled between 15°–25°, lower than the recommended angle for inland areas (typically local latitude + 5°–10°), to reduce the wind-facing area during typhoons
• Dual-bolt fastening method instead of traditional single-bolt fixing, enhancing panel stability in strong winds
• Stainless steel safety chains added between panel frames and lamp arms as a safety redundancy under extreme conditions
• Slightly increased solar panel wattage (15%–20% higher than inland configuration) to compensate for power generation efficiency loss from the reduced tilt angle

4. Real-World Case Studies: High-Salt-Fog Coastal Environments

Case 1: Shan’ge Village Rural Lighting Project, Changkeng Township, Anxi County, Quanzhou, Fujian

Project name: Shan’ge Village Rural Lighting Project, Changkeng Township, Anxi County, Quanzhou, Fujian Province

Project date: May 3, 2020

Project location: Shan’ge Village, Changkeng Township, Anxi County, Quanzhou, Fujian Province

Project background:

Shan’ge Village is located in Changkeng Township, Anxi County, Quanzhou, in the mountainous region of southern Fujian, approximately 80 km from the Quanzhou coastline. Although Shan’ge Village itself is not directly on the coast, the overall climate characteristics of the Fujian coastal region — high humidity, abundant rainfall, and hot summers — impose high anti-corrosion requirements on outdoor lighting equipment. Anxi County has a subtropical oceanic monsoon climate with an annual average relative humidity above 80%, annual precipitation of 1,600–1,800mm, and a prolonged plum rain season with high atmospheric moisture content.

In early 2020, Shan’ge Village prioritized road lighting improvement as a key annual livelihood project. Given the high cost of laying cables in mountainous terrain and the damp, rainy climate of Fujian, the decision was made to adopt waterproof solar street lights.

Client requirements:

After comparing multiple solar street light manufacturers, Shan’ge Village selected Zhongshan Nande Solar Lighting Co., Ltd., with the following core requirements:

• Luminaires must adapt to Fujian’s coastal damp, rainy climate
• Slopes and curves require higher illumination brightness
• Continuous operation must be maintained during the plum rain season
• Lamp posts must have good anti-corrosion performance and not rust quickly in humid conditions

Solution:

Nande’s technical team developed a differentiated configuration based on the village’s terrain and Fujian’s climate conditions:

Parameter	Main Road Configuration	Alley Configuration
Lamp post height	8m	6m
LED source power	50W	30W
Solar panel	120W monocrystalline silicon	80W monocrystalline silicon
Storage battery	LiFePO4 12V/50Ah	LiFePO4 12V/30Ah
Lamp post anti-corrosion	Hot-dip galvanized + powder coating	Hot-dip galvanized + powder coating
IP rating	IP67	IP65
Rainy day autonomy	5 days	3–5 days

Main roads use 8-meter solar street lights with 50W LED sources to ensure illumination brightness on slopes and curves; alleys use 6-meter solar street lights with 30W LED sources to meet daily traffic needs. All lamp posts use hot-dip galvanized anti-corrosion treatment with electrostatic powder coating, suited to Fujian’s damp coastal climate.

Installation quantity: 110 sets of LED solar street lights installed (36 sets with 8m posts, 74 sets with 6m posts)

Performance:

The project became a benchmark for Changkeng Township’s rural illumination initiative. As of a follow-up visit in early this year, the project had been operating stably for nearly 6 years, with lamp post coatings intact and no obvious signs of rust. During Fujian’s plum rain season in June 2020, the street lights continued operating normally through 4 consecutive rainy days, validating the reliability of the 5-day autonomy configuration.

Client feedback:

The Changkeng Township Shan’ge Village Committee commented: “Nande’s solar street lights are truly high quality. During the plum rain season, even after days of continuous rain, the lights kept shining. The 8-meter posts illuminate the road clearly — no more worrying about slippery roads when riding a motorcycle. After nearly 6 years, the posts still haven’t rusted. The quality is truly outstanding.”

Case 2: Yonghan Town Road Lighting Project, Longmen County, Huizhou, Guangdong

Project name: Yonghan Town Road Solar Street Light Project, Longmen County, Huizhou, Guangdong Province

Project date: September 25, 2019

Project location: Yonghan Town, Longmen County, Huizhou, Guangdong Province

Project background:

Yonghan Town is located in the southern part of Longmen County, Huizhou, Guangdong Province, at the northeastern edge of the Pearl River Delta, approximately 100 km from the Huizhou coastline. Longmen County has a subtropical monsoon climate with an annual average temperature of 21.6°C and annual precipitation exceeding 2,100mm — one of the rainiest counties in Guangdong. Yonghan Town is surrounded by mountainous areas including Nankun Mountain, with consistently high air humidity, hot and humid summers, demanding high waterproof and moisture-proof performance from outdoor lighting equipment.

In the second half of 2019, Yonghan Town launched a road lighting improvement project for the town center and surrounding villages, combining urbanization construction with the rural revitalization strategy. As a key component of the municipal solar street light project, the project required luminaires with excellent waterproof and moisture-proof performance, durable anti-corrosion lamp posts, and an appearance that harmonizes with the overall town aesthetic.

Client requirements:

The relevant departments of Yonghan Town specified:

• Coverage of town main roads and surrounding village roads
• Excellent luminaire waterproof performance for rainy, high-humidity climate
• Strong lamp post anti-corrosion capability for long service life in humid conditions
• Batch supply capability and installation guidance

Solution:

Parameter	Main Road Configuration	Village Road Configuration
Lamp post height	8m	6m
LED source power	50W	30W
Solar panel	120W monocrystalline silicon	80W monocrystalline silicon
Storage battery	Industrial-grade LiFePO4 12V/50Ah	Industrial-grade LiFePO4 12V/30Ah
Lamp post anti-corrosion	Hot-dip galvanized + electrostatic powder coating	Hot-dip galvanized + electrostatic powder coating
Fasteners	SUS304 stainless steel	SUS304 stainless steel
IP rating	IP66	IP65
Rainy day autonomy	5 days	3–5 days

All lamp posts received hot-dip galvanizing treatment (zinc layer thickness ≥70μm) plus epoxy-polyester electrostatic powder coating (coating thickness ≥100μm) for dual anti-corrosion protection. Luminaire housings use ADC12 die-cast aluminum alloy with anodizing treatment, and all fasteners are SUS304 stainless steel.

Installation quantity: 156 sets of solar street lights installed (52 sets with 8m posts, 104 sets with 6m posts)

Performance:

The project has operated stably since delivery. From October 2019 to early 2020, the Guangdong region experienced multiple severe rainstorm and typhoon events — all street lights remained free of water ingress or electrical failures. As of a follow-up visit in early this year, the project has been operating for over 6 years, with lamp post coatings intact, no corrosion signs on luminaire housings, and all lights functioning normally.

Client feedback:

A Yonghan Town official commented: “Nande’s solar street lights have performed exceptionally well in Longmen’s rainy environment. They survived several typhoons and rainstorms without any issues. After 6 years, the posts still show no rust — the quality is solid.”

Case 3: Yangjiang Prison Lighting Project, Yangdong District, Yangjiang, Guangdong

Project name: Yangjiang Prison Lighting Project, Nalong Town, Yangdong District, Yangjiang, Guangdong Province

Project date: December 16, 2019

Project location: Nalong Town, Yangdong District, Yangjiang, Guangdong Province

Project background:

Yangjiang is located on the southwest coast of Guangdong Province, adjacent to the South China Sea — a typical coastal city. With an annual average temperature of 22.3°C and annual average relative humidity of 83%, Yangjiang’s salt-fog deposition rate is among the higher levels for coastal cities. Yangjiang Prison, located in Nalong Town, Yangdong District, is approximately 15 km from the coastline,长期 exposed to a high-salt-fog, high-humidity maritime climate.

Prison lighting has uniquely stringent requirements for safety and reliability — the lighting system must ensure 24/7 normal operation, with no lighting blind spots caused by equipment failure. Accordingly, prison management imposed strict requirements on product quality, anti-corrosion performance, and operational stability.

Client requirements:

Yangjiang Prison management specified:

• High luminaire reliability with no failures during long-term operation
• Excellent lamp post anti-corrosion performance for Yangjiang’s coastal high-salt-fog environment
• Stable illumination, guaranteed even during rainy days
• Extended warranty period and timely after-sales service

Solution:

Nande developed a premium anti-corrosion configuration for Yangjiang Prison’s special requirements:

Parameter	Specification
Lamp post height	8m
Lamp post material	Q235 steel, hot-dip galvanized + nano anti-corrosion coating
LED source power	50W
Solar panel	150W monocrystalline silicon (double-glass module)
Storage battery	Industrial-grade LiFePO4 12V/60Ah
Controller	Storage-control integrated machine, conformal coating + potting treatment
Fasteners	SUS316 stainless steel
IP rating	IP67
Rainy day autonomy	5–7 days
Wind resistance	Level 14

This project used the highest-grade anti-corrosion configuration — lamp posts received nano anti-corrosion coating over hot-dip galvanizing, controllers used full potting process, and all fasteners are SUS316 stainless steel. Solar panels use double-glass modules, completely eliminating backsheet aging risk. The 8-meter solar street lights with 50W light sources ensure adequate illumination brightness and uniformity on prison grounds.

Installation quantity: 48 sets of high anti-corrosion solar street lights installed

Performance:

The project has operated stably since delivery. Yangjiang is in a high-frequency typhoon zone, affected by typhoons every summer and autumn. During multiple typhoon events in 2020 and 2021, the project experienced no lamp post tilting, solar panel damage, or luminaire water ingress. As of a follow-up visit in early this year, the project has been operating for over 6 years, with lamp post coatings intact, no signs of corrosion, and the nano coating’s super-hydrophobic effect still clearly visible. All lights are operating normally, with controllers and lithium batteries in good condition.

Client feedback:

Yangjiang Prison management commented: “Nande’s solar street lights are extremely reliable. Yangjiang is by the sea with heavy salt fog — our previous brands started rusting within 2–3 years. Nande’s posts with nano coating still look brand new after 6 years. Typhoons were no problem. The safety and stability give us real peace of mind.”

Solar Street Light

Solar Street Light

Case 4: Shawei Yi Road Lighting Project, Chengzhong District, Sihui City, Zhaoqing, Guangdong

Project name: Area Lighting Project at No. 45, Shawei Yi Road, 12th Alley, Chengzhong District, Sihui City, Zhaoqing, Guangdong Province

Project date: November 10, 2019

Project location: No. 45, Shawei Yi Road, 12th Alley, Chengzhong District, Sihui City, Zhaoqing, Guangdong Province

Project background:

Sihui City is located in west-central Guangdong Province, under the administration of Zhaoqing City, at the confluence of the Xijiang, Suijiang, and Longjiang rivers. Sihui has a subtropical monsoon climate with an annual average temperature of 21.2°C, annual average relative humidity of 82%, and annual precipitation of approximately 1,800mm. Although Sihui is not directly coastal like Yangjiang or Zhanjiang, the river confluence geography creates high atmospheric humidity, and combined with Guangdong’s widespread “Hui Nan Tian” (spring moisture return) phenomenon, outdoor lighting equipment in the city faces significant dampness and corrosion pressure.

Shawei Yi Road is in the old town area of Chengzhong District, Sihui, with dense alleys and narrow building spacing. Some sections had aging grid-powered lighting with poor illumination, and residents reported safety concerns when traveling at night.

Client requirements:

• Limited alley space requiring easy-to-install lighting solutions
• Luminaires must adapt to Guangdong’s high-humidity climate
• Anti-corrosion lamp posts that won’t rust within a few years, affecting appearance and safety
• Maintenance-free operation with no additional electricity costs

Solution:

Parameter	Specification
Lamp post height	6m
Lamp post material	Q235 steel, hot-dip galvanized + electrostatic powder coating
LED source power	30W
Solar panel	80W monocrystalline silicon
Storage battery	Industrial-grade LiFePO4 12V/30Ah
Controller	Smart storage-control integrated machine
IP rating	IP65
Rainy day autonomy	3–5 days

With limited alley space, 6-meter lamp posts with 30W LED sources were selected, with post spacing of 20–25 meters. Lamp posts use hot-dip galvanized plus powder coating dual anti-corrosion treatment, suited to Guangdong’s high-humidity climate.

Installation quantity: 42 sets of integrated solar street lights installed

Performance:

After project completion, Shawei Yi Road and the surrounding 12th Alley area achieved full illumination coverage. Alley lighting is effective, and residents report significantly improved feelings of safety when traveling at night. As of a follow-up visit in early this year, the project has been operating for over 6 years in good condition. Guangdong’s extreme humidity during spring “Hui Nan Tian” has had no significant impact on the luminaires — lamp post coatings remain intact with no condensation or water accumulation inside the housings.

Client feedback:

Chengzhong District community residents commented: “The alleys used to be very dark — you couldn’t see where you were walking. Since Nande’s solar street lights were installed, the alleys are much brighter. The lights have been working well for years, and the posts haven’t rusted at all. They’re so much better than the old street lights.”

Case 5: Xialiditun New Countryside Project, Sanli Village, Longtan Town, Bobai County, Yulin, Guangxi

Project name: Xialiditun New Countryside Solar Street Light Project, Sanli Village, Longtan Town, Bobai County, Yulin, Guangxi Zhuang Autonomous Region

Project date: July 2019

Project location: Xialiditun, Sanli Village, Longtan Town, Bobai County, Yulin, Guangxi

Project background:

Longtan Town, Bobai County, is located in the southern part of Yulin, Guangxi Zhuang Autonomous Region, approximately 60 km from the Beihai coastline. Although Longtan Town is not directly on the coast, it is influenced by the Beibu Gulf maritime climate, with relatively high salt concentration in the air, annual average relative humidity of 84%, and annual precipitation of 1,700–1,900mm. Particularly during summer and autumn, southeast winds from the Beibu Gulf carry salt fog and moisture, causing continuous corrosion effects on outdoor lighting equipment.

Xialiditun is a natural village under Sanli Village, Longtan Town. As part of new countryside construction, the village had completed road hardening and public activity square construction, with road lighting as a supporting project.

Client requirements:

After learning about Nande’s products, Sanli Village Committee specified:

• Main road illumination brightness sufficient for daily travel and activities
• Luminaires adapted to Bobai’s near-coastal high-humidity environment
• Good anti-corrosion performance and durability of lamp posts
• Strong autonomy for normal operation during Guangxi’s rainy summer season

Solution:

Parameter	Specification
Lamp post height	6m
Lamp post material	Q235 steel, hot-dip galvanized powder coating, white post body
LED source power	40W
Solar panel	100W monocrystalline silicon
Storage battery	Industrial-grade LiFePO4 12V/40Ah
Controller	Smart controller, light control + time control + PIR motion sensor
IP rating	IP65
Rainy day autonomy	3–5 days
Lighting mode	Full power 6 hours + energy-saving mode 6 hours

All lamp posts received hot-dip galvanizing treatment with electrostatic powder coating, adapted to the high-humidity environment of coastal Guangxi. Luminaires use ADC12 die-cast aluminum alloy housings with SUS304 stainless steel fasteners.

Installation quantity: 86 sets of integrated solar street lights installed

Performance:

After project completion, the street lights of Xialiditun became a highlight of Bobai County’s new countryside construction. The 86 sets of lights are evenly distributed along the village’s main roads, providing good nighttime illumination. During Guangxi’s summer rainy season in 2019, even through 3 consecutive rainy days, the street lights maintained normal illumination. As of a follow-up visit in early this year, the project has been operating for over 6.5 years, with lamp post coatings still intact and no signs of corrosion.

Client feedback:

Longtan Town Sanli Village Committee stated: “Nande’s solar street lights were installed to a high standard, with sturdy posts. After more than 6 years, the posts still look brand new — not a trace of rust. The villagers are very satisfied with the new lights. More elderly people and children are using the cultural square for evening activities now.”

5. Daily Maintenance Recommendations for Coastal Solar Street Lights

5.1 Regular Salt Deposit Cleaning

Solar street lights in coastal areas continuously accumulate salt deposits on their surfaces, particularly during dry seasons when salt fog evaporates, leaving white salt frost on lamp post and luminaire surfaces. It is recommended to wash at least twice per year (before and after the rainy season), using fresh water to rinse lamp post surfaces and solar panel surfaces to remove salt deposits. Avoid using acidic or alkaline cleaning agents to prevent damage to anti-corrosion coatings.

5.2 Regular Coating Condition Inspection

It is recommended to conduct a comprehensive coating inspection every 2–3 years, focusing on weld areas, bottom flange plates, and the bottom 30cm of lamp posts — areas susceptible to water accumulation and splash exposure. If local coating damage, bubbling, or rust spots are found, timely repair should be performed. Repair method: first grind away rust to Sa2.5 grade, then apply zinc-rich primer and topcoat to restore coating integrity.

5.3 Fastener Condition Monitoring

In coastal high-salt-fog environments, even stainless steel fasteners may experience bolt seizure due to long-term corrosion. It is recommended to check the tightness of lamp post flange bolts, luminaire mounting bolts, and solar panel fastening bolts annually. Severely corroded bolts should be replaced promptly. When replacing, always use the same material grade (SUS304 or SUS316) stainless steel bolts — never substitute with ordinary carbon steel bolts.

5.4 Solar Panel Cleaning and Inspection

Salt deposits on solar panel surfaces reduce light transmittance and affect power generation efficiency. It is recommended to clean panel surfaces with fresh water quarterly. Also check junction box sealing condition, confirming sealant shows no aging or cracking and terminals show no corrosion signs. If white corrosion products are found on panel aluminum frames, clean with a neutral detergent and apply transparent anti-corrosion wax for protection.

5.5 Battery and Controller Inspection

It is recommended to check controller operating status annually — verify indicator lights are normal and charge/discharge parameters are within range. For systems using storage-control integrated machines, check battery compartment seal condition and confirm the waterproof breathable valve is functioning. If signs of salt intrusion are found in the battery compartment (white crystalline deposits), clean the compartment and replace seals.

Zhongshan Nande Solar Lighting Co., Ltd. provides detailed maintenance manuals and regular inspection checklists for every coastal project, along with remote technical guidance and after-sales support. For maintenance inquiries, contact Manager Mo at 189 2534 3352 or call the 400 service hotline at 400 884 9868.

6. Lamp Post Anti-Corrosion Process Comparison and Selection

6.1 Common Lamp Post Anti-Corrosion Process Comparison

Anti-Corrosion Process	Zinc/Coating Thickness	Salt Spray Test	Suitable Environment	Expected Life	Cost Index
Cold galvanizing (electroplating)	5–15μm	200–500 hours	Inland dry regions	3–5 years	1.0
Hot-dip galvanizing	65–85μm	1,000–1,500 hours	General outdoor environments	15–20 years	1.8
Hot-dip galvanized + powder coating	Zinc 65μm + plastic 100μm	1,500–2,000 hours	Coastal humid environments	20–25 years	2.3
Hot-dip galvanized + nano coating	Zinc 65μm + nano layer 40μm	2,500–3,000 hours	Directly coastal high-salt-fog zones	25–30 years	3.0
Stainless steel lamp post	N/A	Over 3,000 hours	Extreme corrosion environments	30+ years	5.0–8.0

6.2 Cost-Effectiveness Analysis

From a cost-benefit perspective, “hot-dip galvanizing + electrostatic powder coating” is the most cost-effective lamp post anti-corrosion solution for coastal areas. Compared to standard cold-galvanized lamp posts, the cost increases by approximately 130%, but the service life increases 4–6 times, resulting in an annual cost reduction of over 60% across the full lifecycle. Compared to stainless steel lamp posts, the initial investment of the hot-dip galvanized + powder coating solution is only 30%–40% of stainless steel, while the anti-corrosion performance is fully adequate for general coastal environments.

For directly coastal municipal solar street light projects (within 500 meters of the shoreline), the “hot-dip galvanized + nano coating” solution is recommended. Although the initial investment is higher, it significantly reduces later maintenance frequency and replacement costs.

Zhongshan Nande Solar Lighting Co., Ltd., as a solar street light manufacturer, can provide targeted anti-corrosion solution recommendations and cost estimates based on specific project environmental conditions and budget requirements.

7. Zhongshan Nande Solar Lighting Co., Ltd. — A Pioneer in Coastal Solar Street Light Anti-Corrosion

7.1 Company Overview

Zhongshan Nande Solar Lighting Co., Ltd. (formerly known as Wanxing Technology Lighting) was established in 2000 in Zhongshan City, Guangdong Province — China’s “Lighting Capital.” Over 26 years of deep development, the company has grown into a comprehensive enterprise integrating solar PV modules, lithium batteries, controllers, luminaire light sources, and lamp post manufacturing, achieving independent R&D, production, and sales of all core components of solar street light systems.

The company’s factory covers 58,000 m², with a total investment of nearly 20 million RMB, a current workforce of 367 employees, and annual sales exceeding 500 million RMB. Monthly production capacity is 20,000 sets of street light systems, with cumulative deliveries reaching 1 million sets as of last year — delivery capability validated by large-scale projects.

7.2 Coastal Anti-Corrosion Technical Advantages

Zhongshan Nande Solar Lighting Co., Ltd. has accumulated extensive technical experience in anti-corrosion for solar street lights in coastal high-salt-fog environments:

• Comprehensive lamp post anti-corrosion processes: Capable of hot-dip galvanizing, electrostatic powder coating, nano coating, and other multi-layer anti-corrosion processes; lamp post anti-corrosion grade reaches C5-M (marine high-salt-fog) standard
• Self-developed storage-control integrated machine: Controller products receive dual protection through conformal coating and potting, with outstanding reliability in high-salt-fog environments
• Industrial-grade LiFePO4 batteries: Self-developed lithium battery systems have operated stably for over 8 years in coastal high-temperature, high-salt-fog environments with excellent capacity retention
• Full-chain self-production: Five core components (solar modules, lithium batteries, controllers, luminaire light sources, lamp posts) are all independently R&D’d, produced, and sold, ensuring full-process controllability of anti-corrosion solutions from design to production

7.3 Qualifications and Certifications

• Class II Qualification for Urban and Road Lighting Engineering Professional Contracting
• CE, RoHS, ISO9001 certifications
• 12 international patents, 60 national patents
• Product certifications in 30+ countries
• Nande (Hong Kong) Solar PV Laboratory (invested 18 million HKD in construction)

7.4 Coastal Project Experience

From Yangjiang, Guangdong to Quanzhou, Fujian, from Yulin, Guangxi to Huizhou, Guangdong — Zhongshan Nande Solar Lighting Co., Ltd.’s anti-corrosion solar street lights have operated stably for over 6 years across multiple coastal and high-humidity environments, accumulating extensive real-world data and engineering experience. Whether for municipal solar street light projects, new countryside lighting, or special facilities (prisons, ports, islands), Nande provides professional anti-corrosion solution design and product supply.

8. FAQ

Q1: What anti-corrosion process is best for solar street light lamp posts in coastal areas?

A: For coastal area lamp posts, a “hot-dip galvanizing + electrostatic powder coating” dual anti-corrosion solution is recommended. Hot-dip galvanizing provides substrate-level cathodic protection (the zinc layer acts as a sacrificial anode, corroding preferentially to protect the steel substrate), while electrostatic powder coating provides physical barrier-level protection (isolating air and moisture from direct contact with the zinc layer). This dual protection system achieves salt-fog resistance of 1,500–2,000+ hours in coastal environments, with a lamp post design service life of 20–25 years.

For directly coastal areas within 500 meters of the shoreline, adding a nano anti-corrosion coating over the hot-dip galvanized + powder coating base is recommended, creating a super-hydrophobic surface that further blocks salt-fog penetration. Zhongshan Nande Solar Lighting Co., Ltd. can provide tailored recommendations based on your project’s specific conditions.

Q2: How should I choose between 8-meter and 6-meter solar street lights for coastal projects?

A: In coastal projects, the choice between 8-meter and 6-meter solar street lights primarily depends on road classification and road width:

Scenario	Recommended Post Height	Recommended LED Power	Applicable Road Width
Coastal village alleys, intra-village roads	6m	20–30W	4–8m
Coastal township main roads, county highways	8m	40–60W	6–12m
Coastal traffic arterial roads, provincial highways	10m	60–100W	10–16m

When selecting lamp posts for coastal projects, in addition to lighting requirements, wind-resistance design must be carefully considered. For 8-meter solar street lights, with their larger wind-loaded area, the post wall thickness should be no less than 3.5mm, and the foundation specification should be no smaller than 800×800×1000mm to ensure structural safety during typhoons. All lamp post products from Zhongshan Nande Solar Lighting Co., Ltd. are designed to Level 12 wind-resistance standards, with upgrades to Level 14 available for coastal projects.

Q3: What is the difference between IP65 and IP67 waterproof ratings for solar street lights? Which should be chosen for coastal areas?

A: The waterproof ratings are defined as follows:

• IP65: Dust protection Level 6 (complete protection against dust ingress); water protection Level 5 (protection against low-pressure water jets from all directions). Suitable for general outdoor environments, can withstand rain exposure.
• IP66: Water protection Level 6 (protection against powerful water jets from all directions). Suitable for rainy and typhoon-prone areas, can withstand typhoon rainstorm impact.
• IP67: Water protection Level 7 (protection against short-term immersion, 1 meter depth, 30 minutes without water ingress). Suitable for high-salt-fog, high-humidity coastal environments and directly coastal areas.

For coastal areas, at minimum IP65-rated waterproof solar street lights are recommended. For areas within 1 km of the coastline, IP66 is suggested. For directly coastal areas (within 500 meters) or island projects, IP67 is recommended. All waterproof solar street lights from Zhongshan Nande Solar Lighting Co., Ltd. undergo rigorous waterproof testing before shipment to ensure rated IP protection levels are achieved.

Q4: How long can solar street lights last in coastal areas? Do batteries need replacement?

A: The design service life of anti-corrosion-designed solar street lights in coastal areas is as follows:

Component	Design Service Life	Notes
Lamp post (hot-dip galvanized + powder coating)	20–25 years	Regular coating maintenance can extend further
Solar panel	25 years	Annual degradation rate 0.5%–0.7%
LED light source	5–8 years	End of life when luminous output drops to 70% of initial
LiFePO4 battery	8–10 years	Cycle life over 2,000 cycles
Controller	5–8 years	Conformal coating/potting extends service life

Field data from Nande’s self-developed industrial-grade LiFePO4 batteries showing stable operation for over 8 years in coastal projects demonstrates that battery capacity retention can be maintained above 70% in coastal high-temperature, high-salt environments. Within the battery’s design service life, replacement is generally not required. Compared to the 2–3 year replacement cycle of traditional lead-acid batteries, industrial-grade LiFePO4 batteries significantly reduce lifecycle maintenance costs for coastal projects.

Q5: Do solar street lights in coastal areas require special maintenance?

A: Compared to inland areas, solar street lights in coastal regions require more maintenance attention, primarily including:

1. Regular cleaning: At least twice per year, rinse lamp post and solar panel surfaces with fresh water to remove salt deposits, preventing salt frost from accelerating corrosion
2. Coating inspection: Every 2–3 years, check lamp post coating condition; repair promptly if damage is found
3. Fastener inspection: Annually check bolt tightness; replace severely corroded bolts with same-material stainless steel bolts
4. Electrical inspection: Annually inspect controller and terminal corrosion; confirm electrical connections are secure
5. Seal inspection: Every 2–3 years, check luminaire and battery compartment seal condition; replace seals that have hardened or degraded

With proper maintenance, solar street lights in coastal areas can achieve over 20 years of safe use. For maintenance guidance or technical support, contact Manager Mo at 189 2534 3352 or call the 400 service hotline at 400 884 9868.

Q6: What are the anti-corrosion standards for municipal solar street light projects?

A: Current anti-corrosion design for municipal solar street light projects primarily references the following standards:

• ISO 12944 “Paints and Varnishes — Corrosion Protection of Steel Structures by Protective Paint Systems”: Classifies corrosive environments into C1–C5 and CX grades, with C5-M (marine atmosphere) being the primary reference grade for coastal environments
• GB/T 13912 “Metallic Coatings — Hot-Dip Galvanized Coatings on Steel — Technical Requirements”: Specifies thickness, adhesion, and salt-fog resistance requirements for hot-dip galvanized coatings
• GB/T 10125 “Artificial Atmosphere Corrosion Testing — Salt Spray Tests”: Specifies test methods and evaluation criteria for neutral salt spray tests (NSS)
• Relevant transportation standards: Include specific requirements for corrosion protection of highway lighting facilities

Lamp post products from Zhongshan Nande Solar Lighting Co., Ltd. are certified to ISO 12944 C5-M grade anti-corrosion standards, with hot-dip galvanized coating thickness, powder coating adhesion, and salt-fog resistance meeting or exceeding national standard requirements. Third-party inspection reports are available for each batch of lamp post products, ensuring anti-corrosion quality for municipal solar street light projects.

9. Why Choose Zhongshan Nande Solar Lighting Co., Ltd.

9.1 Over 25 Years of Industry Expertise

Zhongshan Nande Solar Lighting Co., Ltd., formerly known as Wanxing Technology Lighting, was founded in 2000 with over 25 years (as of this year) of deep engagement in the solar PV lighting industry. This quarter-century of industry accumulation has enabled the enterprise to amass extensive practical experience in coastal anti-corrosion technology, product design, project implementation, and after-sales service.

9.2 Full-Chain Self-Production

As an integrated comprehensive enterprise, Zhongshan Nande Solar Lighting Co., Ltd. has achieved independent R&D and production of five core solar street light components:

• Solar module self-production — conversion efficiency 18%–22%
• Lithium battery self-development — industrial-grade LiFePO4 batteries, 8+ years stable coastal operation
• Controller self-development — storage-control integrated machine, conformal coating + potting protection
• LED luminaire self-manufacturing — ADC12 die-cast aluminum alloy, anodized anti-corrosion
• Lamp post self-production — hot-dip galvanized + powder coating + nano coating, C5-M grade anti-corrosion

Full-chain self-production ensures full-process controllability of anti-corrosion solutions from design to production, avoiding shortcomings in anti-corrosion performance from outsourced components. As one of the few solar street light manufacturers in the industry, Nande possesses complete capabilities from materials to finished products in anti-corrosion technology R&D and implementation.

9.3 Production Capacity and Delivery Strength

The company’s factory covers 58,000 m² with a monthly production capacity of 20,000 sets of street light systems and annual sales exceeding 500 million RMB. Whether for dozens-of-unit island projects or thousands-of-unit coastal municipal engineering projects, delivery is completed on time and to quality standards. Cumulative deliveries reached 1 million sets as of last year, with delivery capability validated by large-scale projects.

9.4 Proven Coastal Project Track Record

From Yangjiang, Guangdong to Quanzhou, Fujian, from Yulin, Guangxi to Huizhou and Zhaoqing, Guangdong — Zhongshan Nande Solar Lighting Co., Ltd.’s anti-corrosion solar street lights have operated stably for over 6 years across multiple coastal and high-humidity environments, accumulating extensive real-world data and engineering experience.

9.5 Comprehensive Certification System

• Class II Qualification for Urban and Road Lighting Engineering Professional Contracting
• CE, RoHS, ISO9001 certifications
• 12 international patents, 60 national patents
• Product certifications in 30+ countries

10. Contact Information

For coastal region solar street light procurement needs, or to learn about lamp post anti-corrosion solutions, product specifications, and pricing, contact Zhongshan Nande Solar Lighting Co., Ltd. through the following channels:

• Contact person: Manager Mo
• Mobile: 189 2534 3352
• 400 Service Hotline: 400 884 9868
• Official website: //www.nandesolar.com
• Company address: Zhongshan City, Guangdong Province, China

Zhongshan Nande Solar Lighting Co., Ltd. provides full-process service from environmental assessment, anti-corrosion solution design, product supply, to installation guidance. Whether for municipal solar street light projects, new countryside lighting, or special facility illumination needs (ports, islands, prisons), professional technical support and comprehensive anti-corrosion solutions are available.

Call 189 2534 3352 (Manager Mo) or the toll-free hotline 400 884 9868 to obtain solar street light manufacturer pricing and coastal anti-corrosion solutions.

This article is provided by Zhongshan Nande Solar Lighting Co., Ltd. for reference only. Specific product parameters and pricing are subject to actual consultation.