What is a Solar Roadway Lighting System?

The shift from traditional HID lighting to solar LED roadway lights is accelerating. The solar roadway lighting market is expected to grow from $4.1 billion in 2023 to $11.1 billion by 2033, with a compound annual growth rate (CAGR) of 10.5%. It indicates the technology adoption rate and success in numbers.

Manufacturers are now producing compact modular solar roadway lighting systems that require minimum setup and maintenance time. Modern solar roadway lighting systems make shifting from traditional lighting systems co]]’ convenient.

This document can help you understand the basics of solar roadway lighting systems. The blog will start with fundamental information, such as the definition and purpose of solar roadway lighting systems and standard requirements. Next, we will explain the key components of solar roadway lighting systems and dive into their applications. Let's start by understanding what a solar roadway lighting system is.

What is a Solar Roadway Lighting System?

The purpose of a roadway lighting system is to provide illumination of roads to enhance visibility for drivers and pedestrians. The enhancement allows them to judge the on-road conditions and anticipate movements in advance. A lighting system offers security for drivers by minimizing car accidents and preventing crashes. The proper illumination allows vehicles to view road signs together with better terrain observation while helping drivers detect obstacles and check road markings to improve their navigation. An adequately lit road at night provides an attractive environment that increases public contentment.

Solar roadway lighting systems go one step further in providing passage illumination. These systems can easily fit on a typical lighting pole. They have an integrated battery, solar panel, LED lighting, power delivery, and control mechanism. The latest generation can also connect wirelessly to allow centralized management control. Due to their integration, solar roadway lighting systems are much easier to set up and require less labor. In addition, owing to LED chips, they are long-lasting and conform to roadway lighting standards.

- Standards for Roadway Lighting

Understanding standards for roadway lighting is the design basis of any solar roadway lighting system. These standards also determine brightness and installation methods.

• ANSI/IES RP-8-18, Practice for Design and Maintenance of Roadway and Parking Facility Lighting
• ANSI/NEMA C136.40-2023, Roadway and Area Lighting Equipment - Solar Lighting Systems
• Federal Highway Administration (FHWA) Lighting Handbook
• American Association of State Highway and Transportation Officials (AASHTO) Roadway Lighting Design Guide
• State and Local Regulations

The requirements for roadway lighting may vary depending on state and local regulations. The ANSI/IES RP-8-18 is the most comprehensive document providing guidelines for all aspects of roadway lighting. Meanwhile, ANSI/NEMA offers in-depth guidelines for solar roadway lighting systems.

- Standard Solar Roadway Illumination Requirements

Solar roadway lighting systems need to be able to produce illumination as required by their standards. Following these standard requirements will help us save costs while ensuring a safe and secure environment for public roadway users. Here are snippets of the illumination requirement as per ANSI/IES RP-8-18 standard:

▪ Roadway Classification

• Freeways and Highways: These major roads require higher illumination due to higher speeds and traffic volumes
• Arterials: Major urban roads with significant traffic flow
• Collectors: Suburban and rural roads with moderate traffic
• Local Roads: Streets within residential or commercial areas with lower traffic volumes

▪ Illuminance Levels

Major Roads (e.g., Freeways):

• High Pedestrian Activity: Average luminance of 1.2 cd/m² with a uniformity ratio (average to minimum) 3.0
• Medium Pedestrian Activity: Average luminance of 0.9 cd/m² with a uniformity ratio of 3.0
• Low Pedestrian Activity: Average luminance of 0.6 cd/m² with a uniformity ratio of 3.5

▪ Collector Roads

• High Pedestrian Activity: Average luminance of 0.8 cd/m² with a uniformity ratio of 3.0
• Medium Pedestrian Activity: Average luminance of 0.6 cd/m² with a uniformity ratio of 3.5
• Low Pedestrian Activity: Average luminance of 0.4 cd/m² with a uniformity ratio of 4.0

▪ Local  Roads

• High Pedestrian Activity: Average luminance of 0.6 cd/m² with a uniformity ratio of 6.0
• Medium Pedestrian Activity: Average luminance of 0.5 cd/m² with a uniformity ratio of 6.0
• Low Pedestrian Activity: Average luminance of 0.3 cd/m² with a uniformity ratio of 6.0

▪ Pedestrian  Areas

• High Pedestrian Activity: Average illuminance of 20 lux (2.0 foot-candles) with a uniformity ratio (average to minimum) of 4:1
• Medium Pedestrian Activity: Average illuminance of 5 lux (0.5 foot-candles) with a uniformity ratio of 4:1
• Low Pedestrian Activity: Average illuminance of 2 lux (0.2 foot-candles) with a uniformity ratio of 10:1

Components  of a Solar Roadway Lighting System

A typical LED solar roadway lighting system has six major components, and manufacturers may have different approaches to producing each component. As a buyer or roadway management, you must understand these components to judge their output performance better and make a more calculated buying decision. Here are their details:

1  Solar Panels: Types, Efficiency, and Placement

The solar panel is the key component of the solar roadway lighting system. It converts sunlight into electrical current. The solar panel's working mechanism is simple: The panel absorbs sunlight, and electrons get excited in the material to produce a flow of electricity, which is then stored or used.

There are different types of solar panels, and their efficiency depends on the type.

• Monocrystalline Solar Panels (18-22% Efficiency)
• Polycrystalline Solar Panels (15-18% Efficiency)
• Thin-Film Solar Panels (10-12% Efficiency)

The most efficient and high-end solar roadway lighting system uses silicon material with a single continuous crystal structure. Its ability to convert light into electrical energy in low-light conditions is exceptional. These systems provide the most longevity and performance.

2  LED  Light Fixtures: Power Consumption & Luminous Efficacy

The power consumption of an LED solar roadway lighting system depends on the LED chip that the whole assembly uses. Some different brands and companies produce LED chips. However, only a few make the correct color temperature and do not degrade with time. The system needs to properly dissipate the heat these LED chips produce to ensure longevity and efficacy. The popular brands include:

• Lumileds (Philips)
• Cree LED
• Nichia Corporation
• Samsung LED
• Bridgelux

The efficacy is the solar roadway lighting's ability to produce lumens when consuming one watt of power (lm/W). It represents the assembly's ability to convert electrical energy into light energy. A typical solar roadway lighting system will be effective between 100 and 200 lm/W.

3  Rechargeable Batteries: LiFePO4 vs. Lead-Acid Battery Performance

Rechargeable batteries are the key component that makes solar roadway lighting feasible for off-grid systems. We will compare the latest LiFePO₄ batteries with the former Lead-Acid batteries.

Modern solar roadway lighting systems use LiFePO₄ batteries to ensure efficiency and higher energy density. They are superior to lead-acid batteries on all grounds except the upfront cost. Regarding roadway lighting, bearing the upfront cost of LiFePO₄ is more feasible than a hard-to-maintain lead-acid option.

4  Controllers: Regulating Power Flow for Efficiency

The controllers are the key components that ensure efficient battery power utilization. Following are the control methods that most solar roadway lighting systems feature:

• ON/OFF Switch: Manual operation option
• PIR Microwave Sensor: The sensor detects movement and adjusts the brightness of the light in the direction of a pedestrian or car. The lights communicate to ensure maximum roadway visibility for moving objects.
• Timer Regulation Lighting schedule:
  • First 4 hours: 100% brightness
  • Next 4 hours: Alternates between 50% and 15% brightness
  • Final 8 hours: Alternates between 30% and 15% brightness
  • Cloudy day mode: Optimized for energy conservation in low-sunlight conditions

5  Poles  and Mounting Structures: Material, Durability, and Design

Lighting poles and mounting structures vary based on design and local requirements. However, the core philosophy remains the same. The most popular mounting mechanisms are side-mounted (bracket arm) or mast arm mounting, davit arm mounting, and truss arm twin mounting.

These are simple poles with electrical wires running between them to reach the lighting fixture. However, for solar roadway lighting systems, any wire is unnecessary. They come with an easy-to-mount mechanism with angle adjustability for proper lighting and solar light-receiving angles. Manufacturers make these poles with carbon steel, galvanization, and adequate paint. They are hollow from the inside to allow the passing of electrical wires. Solar roadway lighting systems reduce the pole's complexity, reducing the cost.

6  Smart  Sensors & IoT Integration: Motion Sensors, Dimming, and Remote Monitoring

The most recent innovation in solar roadway lighting systems is the introduction of smart features. These features enable the lighting to communicate with the central computer and ensure proper error reporting, remote control, and monitoring. Users can also gather reports on their usage and set adaptive lighting conditions.

The motion sensors can increase the brightness in case a pedestrian comes close or vehicles approach the lighting poles. It will anticipate the car's speed and ensure a clear view of the passage ahead while reducing the brightness of the lights behind it. LED solar roadway lighting enables instant brightness control without any warm-up time.

Applications and Use Cases

Solar roadway lighting systems have wide-scale applicability owing to their modern integrated form. Their integration of IoTs and components makes them relevant to most modern-day uses and applications like the following:

●  Highways

Highways are the major users of solar roadway lighting systems. Authorities can find it challenging to maintain lighting on long routes between states. These systems ensure performance and longevity, ideal for long-term projects like highways.

●  Urban Roads

Ensure that the road remains in focus in a well-lit environment. Otherwise, it can become muddled with the environment. Solar lighting systems can provide a decent cd/m² for such applications. Their modular approach makes them easier to repair. Users can replace only the faulty component with minimum downtime to ensure light on urban pathways.

●  Rural Areas

In some circumstances, living in areas far from urban centers can be challenging due to the absence of a grid. Off-grid solar roadway lighting systems can provide an affordable, maintenance-free solution for enhancing security and accessibility.

●  Smart Cities

Modern cities are turning towards smart technologies. Integrating IoTs, sensors, and remote control improves sustainability and data collection. Lighting systems' performance adjusts in response to user changes in brightness levels and other factors. These improvements result in better efficiency and sustainable operations for future periods.

Key Takeaways & Future Trends

Many stories worldwide favor using LED solar roadway lighting systems for urban, rural, highway, and smart city projects. According to the U.S. Department of Energy's 2020 report on LED adoption, LED roadway lighting saved approximately 9.8 TWh of site electricity in 2018. It was achieved by adapting 49.7 million street and roadway lighting installations, of which 24.2 million used LED technology. These massive savings are an attractive aspect of LED solar roadway lighting.

Solar roadway lighting is advancing in control and monitoring due to the rapid developments in AI-based technologies. The recent development of LiFePO₄ batteries indicates that battery efficiency and longevity will improve, allowing better backups.

If you want an integrated solar roadway lighting system with the most advanced control system and components from well-established brands, visit the CHz lighting website. Their massive collection of unique, modular, integrated, and adjustable brightness solar roadway lighting products is ideal for all applications. The lights can easily fit on the mounting of any traditional lighting pole. Visit their website for CE, RoHS, ISO9000, and ISO14000 certified products. We hope you find your big project product following our guidelines!