Cities will "run themselves" assets are tracked seamlessly, and efficiency skyrockets. Sounding like something out of a science fiction novel only a short while ago, this level of connectedness and integration of systems is a new reality. The lion-share of this automation is due to the dramatic rise in Internet of Things (IoT) research and development. While there seem to be as many definitions as people espousing them, IoT is not new.
Cisco Internet Business Solutions Group (IBSG) defines IoT as "the point in time when more things or objects were connected to the Internet than people" (Evans 2). Evans notes that this was realized between 2008 and 2009 due largely to Apple's iPhone, which was released in 2007, starting the "smartphone era" (Evans 3). Co-authors Dr. Ovidiu Vermesan and Dr. Peter Friess comment on the end result of IoT as, "A world where the real, digital and the virtual are converging to create smart environments that make energy, transport, cities and many other areas more intelligent" (Dr. Friess and Vermesan 22, 23).
This world where everything is connected will almost be ensured by 2015. Evans notes that "Cisco IBSG predicts there will be 25 billion devices connected to the Internet by 2015 and 50 billion by 2020" (Evans 3). IoT is not science fiction, it's not even brand new, but it is growing at an incredible pace.
With this growth in mind, companies are beginning to transition strategically to take advantage of this phenomenon. General Electric (GE) plans to move from Fairfield, Connecticut, to Massachusetts. Chairman and CEO Jeffrey Immelt speak to the advantages of moving, "We want to be at the center of an ecosystem that shares our aspirations" (Olavsrud, CIO). This ecosystem includes prestigious universities such as the Massachusetts Institute of Technology. Tech titan, Nokia, is investing 350 million dollars in IoT. Their CEO, Rajeev Suri, notes, "We are launching a $350 million IoT investment fund through Nokia Growth Partners. Our goal is to help accelerate the broad IoT ecosystem, increase the demand for connectivity, and generate returns from investments in compelling opportunities" (Lomas, Tech Crunch). These investments are no small decision. GE and Nokia are betting that IoT, and its growth, have no end in sight.
With this rapid advance in IoT and companies ravenously pursuing potential profits, one must remember the key behind the IoT movement, sensors and transmitters. To create smarter homes, cities, and societies, automation is crucial. Without automation, routine upkeep is necessary, and efficiency is affected. Sensors and transmitters were once powered by batteries that needed changing. Renewable energy has taken up the mantle, and heat, motion, and light can help power the IoT boom.
With such a wide range of applications, many power requirements can come into play. Home appliances or industrial automation equipment, which is inherently connected to power lines, have power easily available. However, many applications are mobile or are in a location that is inconvenient for line power, so an autonomous power source is needed.
Power requirements also range widely. An asset tracking application on a semi-trailer that uses a cell connection to call in data will need a reasonable amount of power, maybe 5Wh per day. A monitoring sensor calling in status data within an industrial building through Wi-Fi or Bluetooth will take significantly less power, somewhere in the milli-watt hr range. Home security systems communicating to a central computer will require something in the middle.
To supplement or eliminate the need for replaceable batteries, a few autonomous power generation devices have come into use:
Thermoelectric devices can be used as a power source for sensors if a temperature gradient is available. This means a heat source, a heat sink, ambient air, or a cooling fan. The basis of this power conversion is a voltage created between dissimilar materials and current driven with a material by the temperature gradient. The device comprises two dissimilar materials, typically positive and negative doped semiconductors, with their junction at the heat source. The opposite sides of the semiconductors are at the heat sink. The voltage value depends on the specific materials, and the current typically depends on the temperature difference. The semiconductor materials need high thermal resistance to keep the temperature difference high. Still, the amount of power is usually quite small.
Thermoelectric generation is viable for sensors in applications such as engines with a natural temperature gradient. There are no moving parts, so they can be quite reliable.
Kinetic power generation
Cyclic mechanical motion, such as the vibration of a moving vehicle or a human walking, can generate power for sensors. Electromagnetic devices are the most common conversion methods, where a magnet is moved back and forth through a coil by oscillatory motion. Power available is a function of the power in mechanical motion. Small power draws will have minimum impact on the mechanical system, but drawing significant power from human motion will take significant energy from the individual and may be counterproductive. Power generation is also limited to the actual time in motion. This means that power is available when moving but not when parked. Additionally, mechanical motion results in wear or fatigue of some components; therefore, the device's lifetime may be limited.
Photovoltaic power generation
Light of any intensity or wavelength can generate electricity through the appropriate semiconductor PV device. A simple PV device consists of a junction of positive and negative doped semiconductors, which create a voltage at their junction. Light is absorbed by the semiconductor to create carriers that provide the current. The voltage of a single device is determined by the semiconductor properties, while the current will be directly proportional to the light intensity. Single devices can easily be connected in series to deliver voltages from half a volt to hundreds of volts. The solid-state nature of these devices makes them durable and can be quite long-lived. These devices are very versatile but are limited to applications where light is available.
With these three methods in mind, what will help support this massive movement toward a more connected and efficient world? Contact Us to learn more about our IoT capabilities, or leave a comment below!
Evans, Dave. The Internet of Things: How the Next Evolution of the Internet Is Changing Everything. Geneva: International Telecommunication Union, 2005. www.cisco.com. Apr. 2011. Web.18 Mar. 2016.
Lomas, Natasha. "Nokia Growth Partners Announces $350M Fund Focused On IoT." www.TechCrunch.com. Tech Crunch, 21 Feb. 2016. Web.18 Mar. 2016.
Olavsrud, Thor. "How GE Will Bring the Industrial IoT to Life." www.cio.com. 16 Mar. 2016. Web.18 Mar. 2016.
Vermesan, Dr. Ovidiu, and Dr. Peter Friess, eds. Internet of Things: Converging Technologies for Smart Environments and Integrated Ecosystems. River Publishers. 2013. Web.18 Mar. 2016.