September 27, 2021
Why Self-Powered Sensors are the Game-Changer
Equipping objects with computing devices that lets them transmit data over the Internet has promised for years to revolutionize the way businesses operate and individuals live. And although the Internet of Things (IoT) is clearly affecting our personal lives—via smart phones, connected thermostats, wearable fitness trackers, and even water bottles that monitor our drinking habits—it has been slower to reach ubiquity than experts predicted, and far slower than expected to take hold among industrial businesses.
The Trillion-Battery Problem
In 2012, IBM predicted 1 trillion connected devices by 2015. The world didn’t get close to that number. One of the implications of IBM’s trillion-device forecast is volume — that’s a trillion batteries needed to keep those trillion IoT sensors collecting, analyzing, and sending data. Battery life has been the focus of most innovation to date. A paper presented at the 2017 Kyoto Symposium on VLSI Circuits described new methods the industry is working on to extend battery life for IoT devices.
Let’s assume the industry eventually achieves its goal of a 10-year lifespan for the average IoT battery. How many batteries would need to be replaced every day in a trillion-device world? The answer: 273,972,603. Even worse, if industry falls short of that goal and delivers only a two-year battery lifespan, that means every person on the planet (all 7.4 billion) is changing a battery every five days.
We cannot replace over 1 billion batteries every single day. Even in a best-case scenario, powering 1 trillion IoT devices would require replacing 274 million batteries every day. And that’s assuming those batteries all reach their full 10-year life expectancies. Clearly, this is not a feasible plan.
Can We Replace the First 137 million Batteries Before Lunch?
Let’s put this in real-world terms that reflect how you might actually leverage IoT in your own business.
Imagine you were to deploy 10,000 Industrial IoT devices across your facilities—sensors strategically placed to transmit real-time data about the health and performance of your machines and equipment, to monitor temperature and air quality in various sectors, to check for toxins that might have leaked, to relay the status of your steam system, HVAC systems, and other vital infrastructure.
Assuming an optimistic notion of a 5-year average life in those 10,000 batteries, your team would be replacing roughly 2,000 batteries each year, or about 5 every day (think of the household smoke detector problem, but on steroids). Depending on the types of devices we’re talking about, the batteries themselves could cost anywhere from a few dollars to several hundred dollars each to replace. Perhaps even more concerning is that the cost of getting to a remote sensor to change a battery is often much higher than the cost of the battery itself.
All of this helps explain why, according to a 2017 report cited by the Institution of Mechanical Engineers, “Batteries must be eliminated for the Internet of Things to flourish.” This is the most basic problem – the industry is focusing on battery life instead of eliminating reliance on batteries altogether.
5 Reasons Why Batteries Restrict Cost-Effective IIoT Deployments
Battery-powered sensors require manual maintenance
The most obvious issue is that all batteries eventually need to be replaced. As we pointed out earlier, the cost of accessing and replacing dead batteries—because such processes must still be done manually—is often much greater in resources and man-hours than the cost of the new battery itself. This need for frequent manual effort immediately defeats the core value of connected sensors.
Finite lifespans can lead to gaps in mission-critical data
The inevitability of a dead battery can have consequences beyond the marginal labor and capital resources required to inspect and replace batteries. Unless the team overseeing a plant’s IoT sensors discovers a dead battery immediately and can quickly get out to the sensor and replace it, the plant will permanently lose whatever data the sensor would have been collecting and transmitting in the interim. To make matters worse batteries wear out quickly in wireless sensor networks, even when carefully managed.
Because some of an industrial plant’s sensors record and stream data that are mission-critical for safety and compliance, dying batteries can create significant hazards for the business.
To conserve battery life, sensors are often configured to transmit data less frequently
Ideally, an IoT device at an industrial plant—say, a sensor positioned near the facility’s chemical operations to continuously monitor the atmosphere for toxic leaks—should be transmitting its data extremely frequently. Updates several times a minute are ideal.
But every data transmission consumes power. So, to extend battery life, many IoT sensors are configured to transmit data far less frequently than would be ideal—sometimes as infrequently as once every 24 hours.
This can give a plant’s operators an inaccurate picture of the data a sensor is capturing.
Physical dimensions can limit sensor functionality
Batteries are often the largest part of an IoT sensor system, leaving engineers limited choices of which batteries to add to their sensors. Moreover, the size, weight, and dimensions of the battery often limit the usefulness of the sensor. This is because physical characteristics of the battery can restrict both the types of applications a sensor can perform and which other components the battery can coexist with on the sensor’s board, as well as where it can be deployed (with embedded locations off limits due to required battery changes).
Possible safety risks and environmental harm
US National Institutes of Health (NIH) reports that lithium batteries commonly used in IoT sensors “may contribute substantially to environmental pollution and adverse human health impacts, due to potentially toxic materials.”
Continued deployment of battery-powered IoT devices around the world—particularly if these devices are rolled out by the billions or tens of billions as predicted – is especially concerning.
The Battery-less Solution
The solution for the Industrial IoT revolution: an end-to-end system that pulls together all the necessary components for a fully developed and ubiquitous sensing solution—built around wireless IoT sensors that are entirely self-powered.
New patented core semiconductor and wireless networking technology enables devices to operate off low levels of ambiently harvested energy, generating enough power to enable their ultra-low-power operations indefinitely. The sensors operate continuously and will never need a battery.
Energy is harvested from several sources—including low-level indoor solar, outdoor solar, the thermoelectric effect (capturing ambient energy generated from temperature gradient), as well as through the vibration of piezoelectric materials (such as certain crystals and ceramics) and even from radio waves traveling through the environment. Unlike other “low-power,” but single-purpose electronic components that utilize energy harvesting, new complete sensor devices can not only collect an array of data using multiple sensors, but also process, analyze, and transmit that data wirelessly—all on the same battery less power budget.
Think of self-powered systems as “forever sensors,” because they can be deployed without worry about physically inspecting them for maintenance or a battery-level check.
The battery problem has hindered adoption of the Industrial Internet of Things (IIoT) and deprived industrial firms of significant benefits, such as pervasive sensing capabilities that can generate actionable intelligence never before accessible. The solution is an integrated, full-stack pervasive-sensing platform where the entire environment—physical sensor, data capture and processing functionality, wireless communication, analytics and reporting software platform—is designed to operate as a true ecosystem. These innovations can finally help businesses realize the trillions of dollars in value promised by the IIoT.