IoT could cause an energy crisis

May 11th, 2018, Published in Articles: EE Publishers, Articles: EngineerIT, Featured: EngineerIT

The internet of things (IoT) is on an enormous growth path. With the IoT and the industrial IoT (IIoT), the world has a way to collect millions of data points which, with cleverly written algorithms, can turn that big data into tools to supercharge production facilities, eliminate breakdowns and deliver all the good things that go with targeted analytics. But there are unintended consequence, and a particular serious one is energy consumption.

Fig. 1: A hardware solution is under development that is both holistic and extremely energy-efficient.

The enormous number of networked nodes collecting, evaluating and converging data into a network demanding a large amount of energy. While the specifications of most sensors rate power consumption as low, with batteries lasting as long as ten years, it is the accumulative energy consumption by the millions, if not billions of devices that will ultimately be deployed that raises the energy concern.

According to a study by the International Energy Agency in 2013, the energy requirements of all networked devices worldwide corresponded to the total demand for electrical energy in Germany. Now, five years later it is expected that this requirement will almost double to 1140 terawatts per year, with networked IoT accounting for a significant share of this growth. For this reason, it is important that sensors become more even more energy efficient, or perhaps self-powered!

To date, industry and researchers have not come up with a comprehensive solution for each application or developed single IoT hardware that is more energy efficient. Researchers at the several of the Fraunhofer Institutes in Germany want to change this. In its move towards “zero power electronics” (ZEPOWEL) lighthouse project, a hardware solution is under development that is both holistic and extremely energy-efficient. The next generation networked sensors could even be completely self-sufficient.

Fraunhofer researchers propose two levers. Firstly, the nodes themselves are to consume significantly less energy, and secondly, energy savings are to be achieved at the system level. This means that communication with other systems will also save energy. “We want to create a technological platform for a comprehensive IoT application,” explains Erik Jung, project team member at the Fraunhofer Institute for Reliability and Micro integration IZM, one of the contributing research groups in the project.

New technologies are being developed such as an ultra-low-power wake-up receiver, which ensures that a sensor node does not have to transmit data continually, but rather “awakens” at a certain threshold or through an authenticated request from outside. This module is expected to be 1000 times more efficient than existing standard radio solutions. The receiver responds only to authorised and cryptographically secured signals that are actually relevant for it. In this way, the sensor node can remain in standby mode with minimal power consumption and be activated immediately by the wake-up receiver as required.

In addition, the project is aiming at a unique sensor innovation: an air quality sensor coupled with a micro-pump. The pump will then serve as a measuring amplifier by greatly increasing the amount of supplied air. If this attempt is successful, the result will be a sensor that can be built with much less intrinsic sensitivity, while at the same time providing data that is far more accurate. Whereas today’s sensors can deliver 5000 measurements at a power of 1250 microwatts per second, the new sensor is expected to deliver twice as many readings per second with a power of less than 10 microwatts.

A recent outcome of the research is a particulate sensor used in the monitoring of air quality. While measurements of particulate matter used to be extremely time-consuming and could therefore only be performed at a few nodes at the same time, the new technology is intended to enable a denser and more accurate measurement. The intelligent networking of the nodes and the connection to common cloud platforms can be used to create a detailed model of fine particulate emissions in cities. The applications are numerous, for example, traffic flow control could be based on it, and navigation systems could adapt their routes to it independently.

Not only is the collection and transmitting of data optimised, but also the energy. Therefore, a broadband harvester is under development, a kind of harvester for ambient energy. Its efficiency is quadrupled in comparison to the current state-of-the-art technology. To harvest 100 microwatts of power from its environment, it only needs a quarter of the area, namely 5 mm2. The energy harvested in this way is stored in a newly developed thin-film battery, which is integrated directly on the hardware chip.

Researchers explain this concept as follows: “If you throw something on the ground, energy is generated with a bandwidth of a few hertz up to a few kilohertz. An absorber that only resonates at 100 hertz can therefore only absorb little energy from the throwing. However, if a resonator is developed that can absorb energy over a wide frequency range, significantly more energy is harvested from the throwing.”

The ZEPOWEL lighthouse project has also set itself the goal of developing a modular approach based on the plug and play principle. “We offer a module for many applications: it’s a plug-in system, like with Lego blocks. Click – and it works,” explains Erik Jung. The resulting platform consists of individual innovations created by the collaborating Fraunhofer institutes which can be combined as desired. While no specific hardware solution has been created for each IoT application, universal IoT hardware is being developed in this project. Depending on the application, the customer can then “cherry pick” as they prefer.