Custom Solar Street Light Solutions for Large-Scale Road Projects

Through reasonable customized design, solar street lights can fundamentally solve these problems: they do not rely on the power grid, achieve energy self-sufficiency, and significantly reduce the construction cost of long-distance power supply. The modular design of components supports rapid installation and shortens the construction period. The long service life and low failure rate of core components can significantly reduce the investment in later operation and maintenance. For various large-scale road projects ranging from urban main roads to rural roads, customized solar street lights have become the best solution that takes into account economy, environmental protection and practicality.

What types of solar street lights are there?

All-in-one Solar Street Light

Integrated solar street lights integrate photovoltaic panels, batteries, light heads and controllers into one unit. They have a compact structure and do not require additional wiring. Its greatest advantage is its convenient installation, which can be completed by a single person. It is particularly suitable for projects that require rapid laying, such as secondary roads in cities and roads in industrial parks. In addition, the integrated design reduces component wear and tear and makes later maintenance simpler.

Split Solar Street Light

Split-type solar street lights install photovoltaic panels, batteries and light heads separately. The photovoltaic panels can be independently fixed at the top of the light pole or nearby high places, while the batteries can be buried underground or installed in the waterproof box at the bottom of the light pole. This design allows for the configuration of larger-capacity batteries and higher-power photovoltaic panels, providing stronger output stability. It is suitable for scenarios with high requirements for lighting duration and brightness, such as highways and national and provincial main roads. At the same time, it can also adapt to extreme climate conditions such as high altitudes, frequent sandstorms, and heavy rainfall.

Semi-split Solar Street Light

The semi-split solution lies between the integrated and split types. The core components are designed in a modular way, which not only retains the convenience of installation but also supports power expansion and individual replacement of components. For instance, photovoltaic panels can be integrated with light heads, and batteries can be independently configured, or batteries can be integrated with controllers, and photovoltaic panels can be upgraded as needed. This solution is suitable for projects that have dual demands for maintenance convenience and lighting power, such as main roads in towns and villages, scenic area roads, etc.

 

Product Type	Cost Level	Installation Speed	Autonomy (Number of Nights)	Maintenance Complexity
Integrated	Medium to Low	Extremely Fast	3–7 days	Low
Split Type	Medium to High	Medium	7–15 days	Medium
Semi-split / Modular	Moderate	Fast	5–12 days	Medium to Low

 

What Are the Key Points in the Design of Custom Solar Street Light for Large-Scale Road Projects?

Assessment of Sunlight Resources and Sites

Sunlight resources are the energy source foundation for solar street lights and also the primary basis for their design. First, it is necessary to use professional tools to query the annual solar radiation of the project location (unit: kWh/m²), and then determine the minimum installation area of the photovoltaic panels in combination with the seasonal changes in sunshine duration.
 

At the same time, on-site shading analysis must be conducted: whether the trees, buildings, mountains, etc. on both sides of the road will block sunlight. Special attention should be paid to checking the shading situation after the trees shed their leaves in winter and the shading range during the summer when the branches and leaves are lush. For sections with severe obstruction, the height of the light poles, the installation Angle of the photovoltaic panels can be adjusted, or more efficient photovoltaic modules can be adopted.

Illuminance Standards and Light Pole Spacing

The lighting requirements for different types of roads vary significantly. It is necessary to strictly follow relevant standards to determine the illuminance (lux) and uniformity to avoid blind spots or excessive lighting.
 

Road Type	Suggested Average Illuminance (lux)	Uniformity (U0)	Light Pole Spacing
Expressways	10–20 lux	≥ 0.4	30–50 meters
Municipal Main Roads	20–30 lux	≥ 0.5	25–40 meters
Secondary Arterial / Branch Roads	10–20 lux	≥ 0.4	20–35 meters

 

The spacing of light poles should be comprehensively calculated in combination with the light distribution curve of the lights and the installation height to ensure seamless light coverage of adjacent street lights and avoid waste at the same time. For instance, the spacing between high-power lights can be appropriately increased, while for curved roads, the spacing should be shortened to ensure uniform lighting.

Selection of Photovoltaic Modules and Tilt Angle

It is recommended to choose high-efficiency monocrystalline or half-cell photovoltaic panels for the component type. The conversion efficiency can reach 18% to 23%, which can generate more electricity within a limited area and meet the energy demands of large-scale projects.
 

For special environments, customized packaging is required: in coastal areas, components resistant to salt spray corrosion should be selected; in desert areas, anti-sand and dust-proof coatings should be used; and in high-altitude areas, the ability to resist ultraviolet rays needs to be enhanced. The installation orientation is preferentially south (in the Northern Hemisphere), and the inclination Angle is adjusted according to the local latitude, generally equal to the latitude or latitude + 5°, to maximize the reception of solar radiation.

Battery Solution and Autonomous Days Design

The battery selection for large-scale projects directly affects operation and maintenance costs as well as system lifespan. The comparison and suggestions of mainstream solutions are as follows:

 

Battery Type	Lifespan (Years)	Maintenance Requirements	Low-Temperature Performance	Suitable Scenarios
LiFePO4 (Lithium Iron Phosphate)	8–12	Low (no water replenishment needed)	Good (can operate at -20°C)	Preferred choice for large-scale projects
Lead-acid Battery	3–5	High (regular water replenishment required)	Poor (significant capacity decline at -10°C)	Short-term projects or budget-limited scenarios

 

The design of autonomous days should take into account the frequency of local rainy and cloudy weather. Generally, it is recommended to configure backup power for 7 to 15 days. For instance, in rainy areas, it is designed for 15 days to ensure normal lighting even during continuous overcast and rainy days. In arid areas, it can be designed for 7 days to balance cost and practicality.

Lighting Control Strategy

Intelligent control is the key to energy conservation for large-scale solar street lights. It is recommended to adopt a combined strategy of "time period dimming + human body sensing + remote dispatching"

• Time period dimming:

Maintain 100% power before 12 a.m., and automatically reduce to 50%-70% power after 12 a.m., taking into account both lighting needs and energy conservation.

• Human body sensing:

When operating at low power and sensing the approach of vehicles or pedestrians, it automatically increases to 100% power and resumes after a delay of 30 to 60 seconds.

• Remote dispatching:

Managed uniformly through the IoT platform, lighting parameters can be adjusted according to seasonal changes and traffic flow, supporting group control and timed on/off.

Wind Resistance, Corrosion Resistance and Temperature Management

The structure of the light pole should be designed based on the local maximum wind speed. Generally, the wind resistance level should be ≥12. The material of the light pole should be Q235 steel or aluminum alloy, and the surface should be treated with hot-dip galvanizing and powder coating to enhance the corrosion resistance.
 

The protection grade of the lights and batteries must reach IP65 or above to ensure dust and water resistance. The battery compartment should be equipped with heat dissipation and insulation devices: in high-temperature areas, forced heat dissipation design should be adopted to prevent battery overheating and attenuation. In low-temperature areas, insulation layers are configured to enhance the battery discharge efficiency.

How to Quickly Deploy A Customized Solar Street Light Project?

Large-scale road projects have high requirements for construction efficiency. The rapid deployment of solar street lights needs to be optimized throughout the entire process from the initial preparation to on-site operations.

Prefabrication and Zoned Construction

By using prefabricated light pole foundations and modular components, the assembly and debugging of light poles, photovoltaic panels and batteries are completed in advance in the factory. On-site, only foundation pouring and component installation are required, which shortens the construction period. Divide the project into multiple construction sections, and advance each section simultaneously to achieve parallel operations and enhance overall efficiency.

Logistics and On-site Management Optimization

Transport components in batches according to the construction progress to avoid piling up on site. Choose temporary storage points close to the construction section to reduce the cost of secondary transportation. The on-site operation adopts the "assembly line operation" mode: dedicated personnel are responsible for foundation excavation, dedicated personnel for light pole installation, and dedicated personnel for commissioning and acceptance. The division of labor is clearly defined to improve the efficiency of collaboration.

Delivery Nodes and Acceptance Criteria

Clearly define key delivery nodes in the contract, such as the arrival time of components, the completion time of the foundation, and the overall debugging completion time, etc. Set up late penalty clauses to ensure the project progress. Taking the rapid deployment integrated products as a solution example, a single person can install 15 to 20 lights in a single day, which is more than 50% higher than the installation efficiency of traditional split products.

How to Maintain and Operate Large-scale Solar Street Light Projects in the Long Term?

The long-term stable operation of large-scale solar street light projects cannot do without a scientific operation and maintenance system and a flexible business model.

Remote Monitoring Platform

Build a remote monitoring platform to achieve three core functions:

• Real-time status monitoring: Remotely view the voltage, current, light intensity and working status of each street light;
• Fault Warning: Automatic alarms for issues such as low battery voltage, photovoltaic panel failure, and lightdamage, accurately locating the fault location;
• Energy statistics: Calculate the power generation and consumption of individual lights, sections and the entire project, generate energy consumption analysis reports, and optimize control strategies.

Maintenance Cycle and Spare Parts Strategy

Formulate a clear maintenance plan

• Daily maintenance: Conduct remote inspections through the platform every quarter and randomly check 10% of the lights on-site every six months.
• Regular maintenance: Clean the dust on the surface of the photovoltaic panels annually, check the battery connection lines, and test the lighting effect.
• Spare parts strategy: Reserve 5% of the total number of lights in the project as core spare parts (such as lights, controllers, and batteries) to ensure that faults can be replaced quickly.

 

Battery replacement cycle: LiFePO4 batteries are recommended to be replaced every 8 to 10 years, and lead-acid batteries every 3 to 5 years. The warranty period for lights is generally required to be more than 5 years, and the warranty period for core components (photovoltaic panels, batteries) is ≥8 years.

A Comparison of Business Models for Customized Solar Street Lights in Large-scale Road Projects

For large-scale projects, two mainstream business models can be chosen. The core difference lies in cost allocation and risk assumption:

 

Business Model	Core Features	Advantages	Applicable Scenarios
One-Time Purchase	Project owner pays equipment and installation costs upfront and holds full ownership.	Low long-term cost; full control of O&M budget; flexible management if O&M team is available.	Projects with sufficient capital, mature O&M teams, and long-term asset management capability.
Subscription / Service Outsourcing (PaaS)	Annual service fees are paid; vendor provides equipment, installation, and lifetime O&M.	Low initial investment; O&M risks transferred to vendor; simplified management.	Projects with limited funds, lack of professional O&M teams, or preference for risk transfer to suppliers.

 

Procurement and Bidding Suggestions for Customized Solar Street Lights in Large-scale Road Projects

Key Points of the Technical Specification List Template

When conducting procurement tenders, the following core technical parameters must be clearly defined to avoid disputes later on

• Lighting parameters: Luminous flux (≥5000lm), color of light (3000K-5000K), CRI (≥70), illuminance value (conforming to road type standards);
• Energy parameters: Photovoltaic panel power (≥100W), battery capacity (≥100Ah), number of autonomous nights (≥7 days), battery type (LiFePO4 preferred);
• Environmental parameters: Operating temperature range (-20℃ to 60℃), protection grade (IP65+), wind resistance grade (≥ grade 12);
• Intelligent functions: Does it support remote monitoring, dimming, fault alarm, and communication interface type (4G/NB-IoT)?

Suggestions on Acceptance Terms

• Factory testing: Suppliers are required to provide factory inspection reports for each batch of products, including indicators such as luminous flux, battery capacity, and waterproof performance;
• On-site acceptance: After installation is completed, randomly inspect the lights at a ratio of 10% to test whether the illuminance, start-up speed and control functions meet the standards.
• Performance Guarantee: A one-year performance guarantee period is clearly defined. During the guarantee period, the failure rate of the lights shall be no more than 2%, and the battery capacity decline shall be no more than 10%. If the standards are not met, the supplier shall replace or repair them free of charge.

Supplier Evaluation Dimensions

• On-site capability: Whether one has experience in large-scale project construction and can provide a complete construction plan and emergency response plan;
• Supply cycle: Can the production and delivery of components be completed within the time required by the project (generally 30-60 days)?
• Network maintenance: Whether there are after-sales service outlets at the project site or in the surrounding area, and whether they can provide on-site maintenance services within 48 hours;
• Project Reference: It is required to provide more than three similar large-scale project cases (with a length of ≥10 kilometers), and on-site visits are also acceptable.

Cost Analysis and ROI Estimation Methods for Large-scale Solar Street Light Projects

The costs of large-scale solar street light projects mainly consist of initial investment (CAPEX) and operation and maintenance costs (OPEX), with the core being the assessment of long-term economic viability through life cycle cost (LCOE).

Cost Compoleition

• Initial investment (CAPEX) : including lighting fixtures, photovoltaic panels, batteries, lightpoles, foundation construction, installation and commissioning, etc., approximately $800- $1,500 per light(depending on power and configuration differences);
• Operation and maintenance costs (OPEX) : This includes spare parts replacement, cleaning and maintenance, labor costs, etc. The average annual OPEX for the LiFePO4 battery solution is approximately $20-30 per cell, and for the lead-acid battery solution, it is about $40-60 per cell.

Key Points of ROI Estimation

The payback period (ROI) = initial total investment ÷ average annual cost savings (electricity cost + traditional operation and maintenance cost).
 

For example, in a 10-kilometer municipal main road project, 300 solar street lights were installed with an initial investment of 300,000 US dollars (1,000 US dollars per light). Replacing traditional municipal street lights, it saves an average of 80,000 US dollars in electricity costs annually, while the traditional operation and maintenance cost is 20,000 US dollars, resulting in a total annual savings of 100,000 US dollars. Then the payback period = 300,000 ÷ 100,000 = 3 years.
 

The long lifespan (8-12 years) of LiFePO4 batteries is the key to reducing long-term costs: compared with lead-acid batteries (which need to be replaced every 3-5 years), it can reduce battery replacement costs by 1-2 times within 10 years, cumulatively saving OPEX by 30% to 50%, significantly enhancing the long-term return on investment.

List of Computational Elements

The engineering/finance team can fill in the form for calculation based on the following elements:

• Project scale (number of street lights, road length);
• Initial investment unit price (US dollars per light);
• Annual average solar power generation (kWh per light);
• Alternative municipal electricity price (US dollars /kWh);
• Annual average operation and maintenance cost of traditional street lights (US dollars per light);
• Annual average operation and maintenance cost of solar street lights (US dollars per light);
• Battery replacement cycle and cost (US dollars per battery).

FAQ

Q1: How to ensure lighting during continuous rainy nights?

A1: When customizing the design, the number of autonomous days (7-15 days) has been configured according to the maximum rainy cycle of the project location. Combined with the high capacity retention rate of LiFePO4 batteries, it can ensure normal lighting during continuous rainy days.

Q2: Why is it cheaper not to connect to the grid?

A2: If large-scale road projects adopt grid-connected power supply, the cost of long-distance cable laying and grid expansion is extremely high (about 50-100 US dollars per meter). The cost of cables alone for a 10-kilometer road can reach 500,000 to 1,000,000 US dollars, far exceeding the initial investment of solar street lights. Moreover, grid connection requires continuous electricity charges, while solar street lights can save 80% to 90% of energy costs during their lifespan (10 years), making them more economically efficient in the long term.

Q3: How stable is the system under extreme weather conditions?

A3: Through customized design, it can be adapted to extreme environments: in high-temperature areas, high-efficiency heat dissipation components and high-temperature resistant batteries are used; in low-temperature areas, insulation layers and low-temperature discharge batteries are configured; in coastal/desert areas, anti-corrosion/anti-sand components are selected.
 

Whether you are a city infrastructure department, an engineering general contractor or a project investor, if you have any needs, please contact NOKIN. We will tailor a customized solution for you based on your sunlight resources and road types! Let solar street lights reduce costs and increase efficiency for your large-scale road projects, and jointly create a green and sustainable infrastructure future!