Q: What applications do you see energy harvesting as making the most impact in over the next few years?
By Srinivas Pattamatta, vice president business development, Atmosic Technologies
RF or photo/solar energy harvesting benefits a range of Internet of Things (IoT) edge devices across industries. The possibility of energy harvesting as a viable source of power is becoming a reality, and this achievement will result in two scenarios: forever battery life or a battery-free IoT.
Forever battery life or a battery-free future offers a host of benefits. First, the cost savings of buying batteries. Secondly, the cost of resources and time spent replacing batteries. And last, the environmental benefit of eliminating batteries. Some of the applications that could benefit include:
Consumer & Home: Energy harvesting promises to extend battery life or offer smaller, cheaper batteries in home applications like keyboards, mice, remotes, lower-power wearables, and personal asset tracking devices. Energy harvesting can also be applied a step further to home automation sensors, control, and monitoring devices.
Industrial & Enterprise: The forever battery or battery-free world benefits asset tracking, locationing, and beacons. Often in industrial environments, batteries are found in hard-to-reach places that require a tremendous amount of effort to change. Some special locations in certain industries don’t even allow batteries, and RF energy harvesting is the only way to power these devices. Furthermore, devices that monitor temperature and humidity, or track assets can benefit from sensors that can go years without battery replacement.
Medical: In hospitals, there are tens—even hundreds—of thousands of assets. It would take handful of people more than four consecutive months to track them manually. Changing batteries every six months for these devices requires an enormous overhaul of resources and in many cases, there are locations in the hospital that do not want batteries in the proximity. RF energy harvesting would be useful in such cases.
By Ken Imai, Senior product marketing, Renesas Electronics America, Inc.
Power efficiency improvements in recent innovative microcontrollers, sensors, and energy harvesting power generators are opening the door to the application of energy harvesting technology for IoT edge devices, enabling battery-free operation. Semiconductor and energy harvesting technology vendors are not just selling their devices and solutions individually, but also co-developing energy harvesting eco-systems to reduce obstacles encountered by system developers.
Today, most low power IoT edge devices such as remote sensor nodes and activity trackers are battery powered so their lifetime is limited by battery capacity. Typically those devices need battery replacements within a year or two, causing significant maintenance costs, especially when devices are deployed in remote locations or are located in dangerous industrial or biohazardous areas where human access is restricted. The benefit of energy harvesting is clear in these situations because the need for batteries is eliminated, or the battery lifetime is extended by many years.
An important energy harvesting application is building structure monitoring, where potentially thousands of remote sensors are deployed to measure environmental parameters or mechanical stresses that indicate the health of structures, and to facilitate anomaly prediction. In this scenario, battery replacement is not practical and a self-powered solution via energy harvesting is the best option to reduce maintenance and total cost. Similarly, many sensors are deployed in industrial factory environments to monitor equipment and processes. In these cases, the sensors can be powered by harvesting energy from abundant sources such as ambient heat or vibration to save cost by operating battery-free.
By Jeff Shepard, chief operating officer, Technology Group, The Face Companies
The next-generation of energy harvesting devices will eliminate the need for batteries in a rapidly-growing array of low-power sensors, embedded circuits, and wireless communications devices. These next-generation devices will contribute to a rapid acceleration in the growth of the IoT in all its forms.
Batteries—even rechargeables—eventually run out of power, need to be replaced, and most contain toxic materials. Up to now, based on the assumption that there’s no substitute for battery power for most wireless devices, the focus of research and innovation has been to reduce device’s power requirements, thus extending the life of the battery. Ironically, this steady reduction of in power consumption requirements has opened opportunities for the next-generation of energy harvesting devices, delivering the potential to eliminate billions of batteries.
In addition to more efficient sensors and other circuit elements, the advancement of low-power microcontroller and radio technologies will further enable the adoption of energy harvesting devices in favor of battery power.
For example, advanced process technologies are enabling embedded controllers to achieve extreme reduction in both active and standby current consumption, a combination that was not previously possible to achieve in conventional microcontrollers. These extreme low current levels enable system manufacturers to take a step further and completely eliminate the need for batteries in some of their products through harvesting ambient energy sources. The target power level for these advanced devices is as little as 5 µW. Several semiconductor makers are developing similarly ultra-low power devices.
In parallel, the development of low-power wireless communications technologies span a range from narrowband IoT (NB-IoT) to the latest Bluetooth 5 devices, providing more devices that can benefit from advanced energy harvesting devices.
The next-generation of energy harvesting devices will be able to extract useful amounts of energy in a wide range of environments, with increasing flexibility of placement, and they are expected to cost no more than the batteries they replace. When these devices become widely available they will greatly accelerate the growth of the IoT.