Smart Street Lights Revealed: A Comprehensive Guide

Smart street lighting is a rising industry in an era where network communication is playing an important role in people’s lives. According to Market Search Future, the smart street light market industry is expected to reach USD 3.31 billion by 2032, with a CAGR of 23.4%, compared to USD 0.61 billion in 2023. Investors who catch the opportunity to follow this trend will obtain more benefits in the future. Read this passage as the first step in your exploration of smart street lights!

What is a smart street light?

The development of advanced, efficient, and reliable power line carriers and wireless GPRS/CDMA communication technology supports the centralized monitoring and control of the street lights. These smart street lights have the functions of adjusting the brightness according to the traffic, reporting the status of the system, detecting cable theft, and so on. Their intelligence makes it easier to save energy, improve the efficiency of public lighting management, and cut costs.

Working principles of smart street lighting system

Intelligent street light systems usually consist of three parts: the main station, the substation, and the communication system. The main station of the control center is mainly composed of computers and networks. They manage and control the entire system. According to actual needs, the main station can be flexibly configured. Communication systems generally use wired or wireless methods, or a combination of them. The main station and each sub-station are equipped with microcontrollers or other intelligent devices (such as LONWORKS). These devices help them implement data transmission and real-time control through TCP/IP or other protocols. The substation can communicate with the main station, receive and execute commands, control voltage, and feed back data.

Functions and benefits of the lights

1. Sensing and adjusting: The smart street lights can be equipped with different sensors, which can analyze information about noise, air quality, light intensity, etc. The information is useful for energy savings, reducing pollution, and eliminating security risks. Besides, the brightness of the street lights can also be controlled at any time via remote control and other methods.
2. Charging: When electric vehicles run out of electricity on the roads, the smart poles can help charge them.
3. Monitoring the traffic: The monitors on the smart street lamps can let the control center know the travel patterns of vehicles and pedestrians. According to this information, the center can send instructions and decrease traffic jams.
4. Parking lot monitoring: Street lights installed in the parking lot can monitor if there is illegal parking to make management easier.
5. Crime detection and prevention: The sound sensors in smart LED street lights can detect certain sounds, like gunfire. After receiving this information, the police can take immediate action. An example is that the crime rate in Atlanta has dropped by 28% since the city put smart street lamps in use.
6. Natural disaster response: When natural disasters like floods, earthquakes, tornadoes, etc. happen, the street lights can flash in certain sequences or change color. These lights can indicate emergency evacuation routes and guide emergency workers.
7. Providing information for the public: Street lights can display information like shopping area directions and public transportation time tables.
8. Agricultural information: When installed in the countryside, the smart street lights can not only provide illumination for the farmers at any time but also monitor soil moisture, temperature, and other environmental parameters through the environmental sensors.

Types of sensors for smart street lighting

1. Light sensors: Light sensors are the most popular type of sensors for street lights. Common ones are phototubes and photoresistors. The photoresistors can sense the light intensity of the surrounding environment and then convert the optical signal into an electrical signal. 
2. Meteorological sensors: The street lights can be equipped with various meteorological sensor modules. They can collect information about temperatures, moisture, wind speed, wind direction, barometric pressure, rainfall, visibility, and so on.
3. Infrared sensors: infrared sensors can detect the movement of vehicles and pedestrians and provide suitable lighting automatically. When vehicles and pedestrians approach, the infrared sensors can sense the difference in heat in the surrounding environment. Other times, their energy-saving mode will be on.
4. microwave radar sensors: The microwave radar sends microwave signals. When vehicles and pedestrians go by, they will reflect the signal. The sensors can judge if the signal is from vehicles or pedestrians by analyzing the intensity and frequency of the signal. 
5. Water immersion detection sensors: In low-lying areas or rainy cities, the water immersion detection sensors can reduce the loss caused by heavy rain to the greatest extent.
6. Tilt detection sensors: This type of sensor can sense the change in gravitational field and detect if the street lights tilt and the tilt angle.

Communication technology of smart street lighting

The communication technology of smart street lighting consists of wired and wireless methods. The mainstream wired method is power line carrier technology, and the wireless methods are mainly LoRa, Zigbee, NB-IoT, and so on.

• Power line carrier: The controller of street lights connects with the central console through the power lines and exchanges data about electricity consumption and line connection. Power line carriers are simple to install and use, but they have a few disadvantages. For example, the distribution transformers often block the signal of the power line carrier, so the signal can only be sent in one transformer’s area. Moreover, there is a large signal loss (10 dB-30dB) between three-phase power lines.
• LoRa: LoRa is suitable for large-scale IoT deployment and can keep costs low. It is a communication method that supports long-distance communication and consumes little energy. It features low data rates, which improve battery life and boost network capacity. LoRa signals are also very capable of diffraction against obstacles.
• NB-IoT: With the emergence of NB-IoT technology, it has become one of the mainstream wireless control technologies for smart street lights. It offers the benefits of low power consumption, low cost, and high stability. Another notable advantage of NB-IoT is that the network can be quickly deployed without a gateway at places where the signals can reach.
• ZigBee: At first, ZigBee was used in the complex industrial network. Therefore, it is safe, reliable, consumes little energy, and has the capability of constructing a self-organizing network. It is naturally suitable for the complex system of intelligent lighting.

Conclusions

In this passage, we introduce the functions, benefits, sensors, and communication methods of smart street lights. There are many possibilities for smart street lighting. As there are different kinds of sensors and smart modules, the street lights can achieve different functions. Besides, you also have various choices of communication methods. It is doubtless that the smart street lighting industry has potential and is helpful for the development of smart cities. Contact us for more information about smart street lights!