IoT Based Street Light Monitoring System

The more than 350 million bulbs that light up the world consume a humongous amount of energy, which, many estimates put at about 19 percent of world’s energy consumed. These lighting costs are essential and not avoidable, though they cost governments roughly Euro 3 billion every year. Though LED lights are gradually replacing CFL and incandescent lamps, more than three fourths of the existing streetlamps are of more than 25 years old.

Most of these old vintage streetlamps are ON throughout the night, even when there is no one around. Therefore, with the aim of reducing their carbon footprint, while saving both money and electricity, an increasing number of cities around the world are opting in for smart technologies to prevent unnecessary wastage of lights, by means of dimming or automatically switching ON/OFF these lights at night. A pilot project was conducted in Norway, using self-dimming streetlamps along routes with low traffic, at night by Tvilight, an Amsterdam-based company working towards sustainable, smart cities of the future.

Making Street-lights Smart

Smart street-lighting uses wireless technologies to control and monitor the actual amount of energy consumed by these street-lights. This data is then used to initiate suitable measures to reduce energy consumption through power conditioning. The ‘smartness’ of the street-lights is derived from a micro-controller and some sensors coupled with a wireless module. This entire unit is called the controller. This, when installed on the street-light pole, would communicate data between street-lights and thus control LED street lighting depending on traffic flow. Data generated from each street-light, is then passed on to the base-station via wireless means, thus enabling a real-time monitoring of the system. The mode of operation can be chosen as either manual or auto mode. The control system can be programmed to turn-off lights as per a predetermined schedule. This system can also be programmed to vary the intensity of lighting to suit predetermined situations.

Light Dependent Resistors (LDR) sense light and it automatically switches OFF lights. This results in huge energy savings and avoids wastage of energy by glowing street lights in unwanted areas. The whole system can be operated using solar energy with a battery backup. Sensors using Passive Infra Red (PIF) technology are used to sense the presence of people and the light intensity of an area. This data is then transmitted wirelessly to the controller, which in-turn switches ON/OFF the streetlight or enables dimming or brightening of the area, depending on the presence or absence of people. This is highly effective in areas experiencing low traffic at sometimes of the night.

Old v/s New Technologies

A detailed study of the existing and new technologies gives us a better perspective of the advantages and disadvantages of both systems. These can be listed as follows:

Disadvantages of Existing System

• Manual Switching off/on of Street Lights
• More Energy Consumption
• High expense
• More manpower

Advantages of the Proposed System

• Automatic Switching of Street lights
• Maintenance Cost Reduction
• Reduction in CO₂ emission
• Reduction of light pollution
• Wireless Communication
• Energy Saving
• Reduction of manpower

How Smart-lighting Works

The smart street-lighting system consists of IR sensors, LDRs, microcontroller, relays, transmitters, receivers and Wifi Modules linked up to each other over wireless media. The resistance of an LDR decreases when light falls on them and increases in the absence of light. Vehicles passing by a street light are detected by IR sensors. Relays are used to switch on/off the street-lights. Transmitters and receivers are programmed microchips that control a computer’s interface to its connected street-light system. This real-time information and data can be accessed over the internet from anywhere, anytime.

An IoT based smart street-lighting system is a cost efficient, practical, eco-friendly and the safest way to save energy. The status information is easily accessible anytime and anywhere. This very efficiently eliminates the problems of saving of energy and also disposal of incandescent lamps. However, the initial cost of installation and maintenance can be the deterrents to adoption of this system.

The development of LEDs has resulted in lighting systems with long life, cool lighting, devoid of any toxic material and fast switching capabilities. These result in several advantages that outweigh the current limitations. Considering the long term benefits, the initial cost should never be a taken as a limiting factor, due to faster Return on Investment (ROI). The scope of such a system can be expanded to include other applications such as industrial lighting, campus lighting and parking lots of huge shopping malls etc. This can also be used for surveillance in corporate campuses and
industries and security applications.