Smart solar street light 

 

Smart solar street light – built-in system and wireless control

1. Introduction 

Solar street lights play a crucial role in municipal street lighting, similar to standard AC LED street lights. What sets them apart and makes them popular is their ability to operate without consuming electricity. With the rise of urbanization and population growth in recent years, the demand for electricity from households and governments has surged, leading to resource shortages. Traditional energy sources like oil and coal are unable to keep up with the increasing demand. Research indicates that a significant portion of electricity (around 70%) is utilized for urban development, with a considerable amount being used for municipal street lighting. As a result, there is a growing interest in renewable energy sources such as solar, wind, and tidal energy.

To address the issue of power consumption, solar energy is harnessed to power street lights. The process involves converting solar energy into electrical energy through solar panels and storing it in batteries. During nighttime, the stored electrical energy powers the street lights to illuminate the roads. While solar street lights help save on electricity consumption, providing continuous lighting throughout the night can quickly deplete the battery's energy. To ensure uninterrupted lighting, designers must invest in larger solar panels and batteries. Smart solar street lights now incorporate intelligent control systems for enhanced energy efficiency. Features like timer dimming, motion sensors, and wireless controls are utilized to regulate the light output at night. By implementing these smart control methods, street lights can be turned on and off at specific times, adjust brightness levels based on ambient light and road usage, ultimately reducing electricity consumption and promoting environmentally friendly lighting. This article will delve into the application and advantages of smart control in solar street lights.

solar street light systems

2. Benefits of smart solar street light

Using lights sensibly to lessen light pollution

When needed, smart solar street lights can turn on or dim the lights in the middle of the night as traffic (vehicles and pedestrians) progressively decreases, and then gradually turn on the lights again in the early morning when the city comes to life. When essential, smart solar street lighting can reduce the environmental impact of unnecessary solar street lighting while still illuminating the road.

Extend lifetime of street lamps and batteries

The smart solar street light does not always need to be operating at full capacity thanks to the illumination control. It is highly compatible with power supply and LEDs. The causes are as follows: 

1. Operating at a lower wattage can help the lamp last longer by preventing heat buildup. 

2. Battery life can be extended and power consumption can be decreased with reduced power operation. 

We are aware that the depth of charge and discharge as well as the number of cycles have an impact on the battery's lifespan. The battery will swiftly achieve the designated cycle number of charge and discharge if it is required to power the lamp for an extended period of time. Additionally, the focus on power reduction makes  the battery not need to be deeply discharged, which is very helpful to prolong the battery life.

Reduce configuration of solar street light to reduce cost

During a working cycle, smart control significantly lowers the solar street lighting system's power usage. As a result, the system's battery and solar panel arrangement will be lower than it was previously. Since the batteries and solar panels in solar street lights make up around 80% of the total cost of the light, reasonable control will significantly lower the cost of the entire set.

Green and environmental protection: promising avenues for growth

The development of solar street lights is somewhat hampered by the fact that their initial construction costs are significantly greater than those of conventional AC street lights. It is possible to regulate the cost of smart solar street lights by minimizing the arrangement of solar panels and batteries. Furthermore, the payback period of solar street lighting is getting shorter and shorter as energy costs rise. Wireless control is capable of efficiently monitoring solar street lighting in the interim. With the sensible leadership of the municipal construction team, we believe that this eco-friendly and green solution may gain increasing traction.

3. Smart solar street light with built-in control system

Solar street lights normally have the ability to turn on and off on their own without the need for extra light management techniques. The idea behind its realization is this: the solar controller is able to measure the output voltage, also known as the charging voltage, from the solar panel and uses that information to determine whether to turn on or off the solar street light switch. The brightness of the sun determines the solar panel's output voltage, which is also the controller's charging voltage. The solar street lamp will switch on when there is little light coming from the sun and the solar controller's charging voltage is low. The solar controller will turn off the solar street light when the brightness of the sun progressively increases along with the charging voltage of the controller.

4. Solar street light in sunny day

Solar street lights in this scenario will be operational from nightfall until dawn. To obtain more energy savings, we can configure time-based dimming using the controller's built-in functionality. The rationale is that there won't be as many cars and people after midnight, therefore illumination levels can be lowered in accordance with lighting needs. Rainy days might then be used to store the power that was conserved. The dimming curve in this mode can be adjusted to 4-5 gradients. For instance, an hour after turning on the light, it is 80% on, and for the remainder of the first part of the night, it is 100% on. And from 0:00 to 4:00, 30% of the light is on. We can turn the brightness up to 100% in the morning to prepare for the first hour or two of light rush hour traffic.

5. Solar street light in rainy day

There is a more cost-effective solution than simply increasing the panel and battery size. Intelligent solar control systems are now the preferred method for managing solar street lights. These systems can automatically adjust the brightness of the lights (load power) based on the available battery capacity. This works in conjunction with time-based dimming, where the system optimizes light output throughout the night.

For instance, imagine the battery falls below 40% capacity. The intelligent controller might determine a safe light level (load power) of 60%. If users programmed the system for full brightness (100%), the controller would override and deliver 60% to conserve power. Conversely, if users set a low light level (20%), the system would simply deliver that amount. This intelligent control ensures the lights function for extended periods during low sunlight days, without the high upfront cost of massive batteries and panels.

6. Solar Street Lights with Motion Sensors: A Smarter Approach

Building on the concept of intelligent control, solar street lights can be equipped with motion sensors to further optimize efficiency. Unlike timer-based dimming, motion sensors adjust lighting based on real-time use.

Here's how it works: When the sensor detects movement (pedestrians or vehicles), it signals the LED driver or controller to increase light output, ensuring proper illumination for those using the path. Conversely, during periods of inactivity, the sensor triggers a reduction in power (through a 3V, 5V, or 0V signal) prompting the light to dim to 30%, 50%, or even completely shut off.

Solar Street Lights with zigbee

7. Smart Solar Street Lights: Unleashing Power with Wireless Control

Building on intelligent control systems, wireless technology offers another layer of functionality for smart solar street lights. Similar to the Zigbee and LoRa methods used in general street light control, wireless connectivity allows for centralized management of individual lamps and entire lighting systems, significantly reducing energy consumption.

But the benefits go beyond simple on/off control. By integrating Internet of Things (IoT) technology, wireless control systems unlock a range of features accessible through an online platform:

• Remote Lamp Management: With a connected wireless module, the system can receive commands from a remote server to turn lamps on or off as needed.
• Dynamic Lighting Control: This allows for adjustments beyond basic on/off functionality. For instance, during thunderstorms, lamps can be switched on early for safety. Similarly, during festivals, brightness can be increased to meet pedestrian and vehicle needs.
• Scene Profiles: Different dimming profiles can be set for various seasons. Imagine setting a summer profile with full brightness for the first four hours after dark, followed by gradual dimming throughout the night, and a brighter morning light activation. Winter profiles can be adjusted accordingly, ensuring optimal lighting for each season.
• Real-Time Monitoring and Maintenance: The wireless system provides real-time status updates on individual lamps, allowing for immediate identification of lamp failures, location pinpointing, and even potential cause diagnosis—all accessible online. This empowers road managers to promptly inform maintenance personnel for swift repairs.

In essence, wireless control systems transform solar street lights into a connected network, enabling efficient energy use, centralized management, and proactive maintenance, all contributing to a smarter and more sustainable lighting solution.

Smart solar street light with wireless control

8. Conclusion

In conclusion, smart solar street lights offer a compelling solution that is both easy to manage and environmentally friendly.  They eliminate the need for manual intervention, reduce energy consumption for greener operation, and minimize maintenance costs. These advantages position smart solar street lights for widespread adoption.

Furthermore, their intelligent systems can serve as a cornerstone for developing smart city infrastructure. Integration with various technologies like camera monitoring, traffic management systems, environmental sensors, weather monitoring tools, and even Wi-Fi opens doors to a range of extended functionalities.

As technology continues to evolve, we can expect even more innovative applications to be seamlessly integrated with solar lighting systems. This will undoubtedly propel the widespread adoption of smart solar street lights, paving the way for a brighter and more sustainable future for our cities.