With the advent of technology, there is a vast spread in the use of Internet of Things (IoT) in various segments such as energy, cities, logistics, homes, industries, health, and agriculture. According to Gartner , there will be 26 billion devices using this technology by 2020. IoT is a technology that involves connecting physical things to the Internet thus, enabling them to communicate and transfer data over the Internet.Introduction of IoT has made the grid smarter, reliable, efficient and robust. Several architectures are available for IoT implementation in smart grid (SG). A basic three layered architecture is shown in figure1.
The smart grid can be divided into four phases power generation, power transmission, power distribution and consumer consumption. Role of IoT in all the four elements has been discussed below.
In past few years, countries across the globe have realised the immediate need of setting up renewable energy systems such as solar and wind energy systems. In case of solar energy, a large amount of area receiving proper sunlight throughout the year is chosen and PV cells are installed thus, making a solar farm. Recently, India has unveiled the world’s largest solar farm, Pavagada solar park with a capacity of 2GW. Also, thew government of India has been promoting installation of PV panels on rooftops of buildings to fulfil ever increasing energy needs. Similarly, large number of wind turbines are installed in areas where wind velocity is relatively high. However, solar and wind power is intermittent in nature and depends highly on weather conditions and location. Therefore, it causes challenges for reliability and predictability of power supply. Here, IoT based system uses sensors such as temperature, humidity and wind speed to collect weather information in real-time and store the sensor data. The data helps in weather forecasting and hence, helps in forecasting energy availability in future.
IoT technology helps the end user to keep a check on electrical parameters like current and voltage. Current and voltage sensors are installed on the PV panel output, DC boost converter output and battery. It is then connected to a control unit. The control unit receives the sensor data and pushes it to a cloud database for storage. The data is remotely monitored in real time by the end user on an app or web interface as shown in figure 2. Here, net metering can be realised more efficiently since the user can make an informed decision about selling stored solar energy back to the grid. Similarly, IoT based real time remote monitoring and control systems find uses in wind, hydroelectric and thermal power plants to monitor health of machinery, electrical parameters and control equipment over the internet.
Traditionally, the monitoring of transmission system was performed manually. Periodic visits were conducted to check the equipment status. Unlike generation and distribution systems, the transmission system is widely spread over a huge area. This poses great challenge for manual patrolling as towers and lines are located in remote areas. IoT based online monitoring system for transmission towers provides a more robust and reliable means. The tower faces damages due to many factors such as cyclone, thunderstorm, earthquake, illegal construction and theft which might lead to collapsing of the tower. Tilt, vibration, weather sensors and cameras installed on towers can transfer accurate status of tower data to the officials.
The online monitoring of transmission line facilitates early detection of faults and their resolution. Conductor temperature and wind affect can be monitored to keep a check on the line performance and status. Also, IoT based monitoring of electrical parameters at each tower using power analyser will enable the officials to identify if there’s a greater than expected loss of energy. Greater loss of energy may imply theft of electricity and hence the officials can act accordingly.
The authorities can distribute power more efficiently in this IoT aided smart grid era. Smart energy meters send the consumption data to the cloud. Hence, the authorities have complete information regarding the load consumption in each location and at each instant of time. They can reorganise their scheduling plans based on load requirement and make the distribution efficient and optimised. This will improve reliability and cost effectiveness.
Also, there is a lot of human effort required in physically going and keeping a check on generation, transmission or distribution machinery. This human labour is reduced with application of IoT devices and systems. The online monitoring helps in identifying the equipment requiring attention and its location. This helps the authorities in state maintenance, staff positioning for patrolling, equipment status reports and weather monitoring.
With the help of IoT, the system can identify faults immediately and take a suitable action. A smart distribution grid may have temperature, humidity, noise sensors for monitoring of distribution grid. Tower tilt sensors are also used to notify the authorities about tilt status of towers and to take action for maintenance if it has reached a certain tilt angle.
The power from distribution center is distributed to consumers, both residential and industrial. Role of IoT in making the consumer consumption intelligent is discussed.
Home & Building Automation System
IoT plays a major role in modern home and building automation systems. The system consists of: –
i. Intelligent lighting system: Passive Infrared sensors are used to monitor movement in the room and the lights are switched off automatically if there is no movement for a specified period of time. The light switch is connected to the internet and the end user can remotely monitor the status of lights in each room and can switch on/off the lights from the web or app interface itself.
ii. Intelligent Appliances – The modern day appliances such as TV, Washing Machine, Refrigerator, and Air Conditioner etc. are connected to the internet thus making them smart. It is now possible to switch on the AC and set it to an optimum temperature over the internet, five minutes before you reach the home from work. Sensors such as power analyzers can be installed at the appliance socket to measure the power consumed by each appliance. The sensor can be connected to a control unit which will act as a gateway and transfer sensor data to the cloud. Thus, the end user can remotely monitor and control each appliance.
iii. Elevator monitoring system – There are multiple elevators in a building. It is difficult to know the status of each elevator at the same time. The control unit of the elevator can be connected to the internet and hence enable the end user to check the status of the all the lifts in a building on a web or app interface in real time.
- Safety and Security – Gas and smoke sensors are used to detect fire and raise an alarm. The internet connected control unit can automatically notify the nearest firefighter unit via automated mail or message over the internet incase sensors cross a specified threshold value. IoT based surveillance systems are used for real time remote monitoring of home or building.
Smart Energy Meters
Traditionally, it required human effort to read power consumption at specific intervals from energy meter at consumer premises. It has disadvantages such as additional cost of meter reader, prone to human error and safety issues due to meters being installed inside consumer’s premises. Smart Energy meters are an essential element of the Smart Grid (SG). They send the power consumption data to the cloud. Both the authorities as well as the user can keep a check of the power consumed in real time via a web or mobile app interface. The user can also perform analytics to predict the monthly bill based on his usage data.This IoT based Advanced Monitoring Infrastructure (AMI) is more reliable, robust, efficient and cost effective. A block diagram depicting smart home and smart energy meter is shown in figure 3.
Electric Vehicle Management System
Electric Vehicles (EVs) are gaining popularity and in near future the number of Electric Vehicles on road will increase in India. The EVs use battery system to store energy and research is being carried out to implement Vehicle to Grid (V2G) system as it’ll provide more stability and robustness during peak loads and failures. As per the need, the EV user can charge battery (Grid to Vehicle, G2V) or can sell stored energy back to the grid (V2G). Using IoT, measured Battery State of Charge (SOC) is sent to the cloud and it enables user to remotely monitor SOC in real time with the help of a web or app interface. Thus, IoT integration helps the user in real-time monitoring and it’ll help the user to make an informed decision to either charge the battery or send energy to the grid (G2V and V2G).
IoT based systems are a key feature in modern day smart cities. A smart city may have the following systems:
- Smart street lighting: IoT based smart street lighting can have components such as LDR (Light Dependent Resistor), Relays, Passive Infrared (PIR) sensor and real time clock. The components connect to a control unit which is connected to a central control unit over the internet. All the street lights are monitored online and can be switched on/off over the internet. LDR changes resistance based on light and hence, can be used to adjust brightness of lighting based on weather condition.
- Water Supply and Storage: Distance measuring sensors can sense the level of water in the storage tank. Hence, the water level is monitored in real time and valves can be closed at a particular required level. Rate flow sensor checks if there’s any leakage between two successive sensors. The rate flow is monitored online and any sort of leakage or theft is reported.
- Surveillance: IoT based surveillance systems are being monitored in real time by the authorities remotely. In case of accident or other incidents, the captured video can be analysed using image processing techniques and necessary action can be initiated.
IoT has proved to be a revolutionary technology and has brought immense scope and opportunities for innovation in every sector. With the energy sector pushing its focus towards renewable energy and electric vehicles round the corner there is need for utilities to invest in innovation which brings reliability, robustness and cost effectiveness to the existing grid elements. We can achieve real time remote monitoring and gather information through sensors. The dataset can be analysed by using machine learning algorithms to optimise scheduling, studying and predicting load patterns and increasing efficiency. The demand for energy has been on a rise consistently in India and implementation of IoT in smart grid will definitely benefit the utilities.