by Rushan Arshad

Today we live in a smart world; our lives are powered by smart watches like Fitbit, smart doors, fridges, assistants, glasses and other devices which generate data. To generate this data, all smart things — collectively known as “Internet of Things” (IoT) — must consume energy in some form. While the main energy source for IoT based devices are lithium ion batteries, technologies like fuel cells, which converts electromechanical energy to generate electricity, are being explored. Patrick Nelson from Network World analyzed the increase in electricity or energy consumption and states that it is not only the energy used to power smart devices that is increasing, the production lifecycle also needs attention if we want to control this hike. A report in Gartner predicts that there will be more than 25 billion devices connected to the internet by 2025. That is almost four devices for every person on this planet, even though only 55.1% of the entire global population has access to the internet.

This leads to an important question: what is alarming about connecting that many devices to the internet? These devices fulfill a purpose in daily life activities, and provide a means for intelligent and informed decision making. However, these devices are collectively a threat to our environment. In this article, we will discuss the challenges of energy efficiency, the greenhouse effects posed by smart devices and the measures we can take to protect our environment and to reap the benefits of the smart environment simultaneously.

Internet of Things and its Applications

The Internet of Things (IoT) is a concept which sees the connection of sensors, actuators, and other smart devices to sense, collect, and transmit information from physical world to the digital world. IoT will be an integral part of the Information and Communication Technologies (ICT) industry in the coming years.

There are ranging domains in which IoT is being utilized, including:

  • Smart homes: Our homes can be equipped with sensors like Radio Frequency Identification (RFID), temperature sensors, and smart appliances. With the help of data collected from them, informed decisions can be made to save money as well as energy.
  • IoT in transportation: IoT applications are also being used in the logistics industry. Products that are shipped from one city or country to another are tracked using RFIDs, providing detailed, real-time information about the transported goods.
  • Smart cities: The concept of “smart cities” has gained a lot of traction over the last few years. It is the combination of different domains like smart security, smart homes, and more, under one roof.

Energy Challenges in IoT and ICT

Each IoT device consumes energy in some form to collect and transmit data, which are collectively stored in massive data centers that also require a lot of energy to operate. According to research conducted at Yale, the biggest data centers, those covering an area of approximately one million square feet, consume the same amount of energy as a city of one million people. This could trigger a huge energy crisis as we are already running out of traditional energy resources like fossil fuels, hydel power generation etc.

Another significant challenge posed by the prevalence of IoT and ICT, in general, is the emission of carbon dioxide (CO2) by smart devices. IEEE Green ICT initiative reports that out of total CO2 emissions, the ICT industry is responsible for 2%, a number that is set to double in the next three years. According to research conducted by researchers in Greener Electronics, for every 18 kilowatt hours of electricity consumed, one tree is required to neutralize the carbon footprint produced by that electricity. And a study related to electricity consumption by ICT industry showed a total of 18-20 petawatt hour (200 terawatt hour) of energy was consumed by the ICT industry in 2007. That means we would need billions of trees just to neutralize the carbon footprints of the ICT industry which is not a viable option. With the prevalence of IoT, we need divergent strategies to counter CO2 emissions.

Possible Solutions

This is where the concept of “Green IoT” comes into the picture. Green IoT seeks to reduce the energy consumption of IoT devices by making them more energy efficient during the manufacturing process. The concept of Green IoT is depicted in Figure 1.


Green IoT Concept by Rushan et al.

In the paper “Green IoT: An Investigation on Energy Saving Practices for 2020 and Beyond”, which I co-authored, we proposed the following solutions to reduce IoT energy consumption by a significant amount:

  1. Use of selective sensing: Sensing devices should only be used when there is some data to be gathered; otherwise they should be turned to sleep mode to save energy.
  2. Efficient policymaking: Devising energy-saving policies can have a significant and direct impact on the amount of energy consumed by ICT. Laws should be made in accordance with these policies.
  3. Intelligent tradeoffs: Energy can also be saved by making tradeoffs on communication, processing, and costs like compressive and selective sensing.


The prevalence of IoT and ICT industry is at its peak and is predicted to increase exponentially in the next decade. To save our scarce energy resources and to save our environment from dangerous carbon footprint, continued research and increased cooperation between a number of stakeholders—including IoT manufacturers, policymakers, and consumers—will be necessary.


R. Arshad, S. Zahoor, M. A. Shah, A. Wahid, and H. Yu, “Green IoT: An Investigation on Energy Saving Practices for 2020 and Beyond,” IEEE Access, pp. 1–1, 2017.

E. Jardim, “Guide to Greener Electronics,” 2017.

Rushan is a postgraduate in Science and Technology from Bournemouth University, UK and specializing in IoT. I aim to pursue my PhD related to IoT, Security & Privacy in IoT and Blockchain in IoT.