The internet of things adds connectivity. It is a broad term referring to applications as diverse as internet connected vehicles to consumer electronics such as smart phones. However, the edge of the internet of things network will consist of simpler sensors and wireless devices that provide, among other things, the identification of objects, sensing, control and automation. The simplest, passive radio frequency (RF) devices, with relatively short range, will potentially be the highest volume of all devices and come in at the lowest price points. Adding power to these devices enables more functionality such as sensing, mesh networking and automated control.
However, the return on investment of many wireless sensors in different applications is dependent in part on the lifetime of the device, which is most usually a function of the battery lifetime. A device lasting ten years versus two has a dramatic change on the return on investment (ROI) calculation, particularly if these sensors are embedded in devices adding significant labour cost for battery replenishment.
This is where energy harvesters can help, however, there are several challenges moving these to market. The first is buyers buying on cost for the short term. The cost of a primary battery is less than that of an energy harvester and associated interfacing electronics. Over the life of the energy harvested powered device the energy harvester version may be cheaper, but buyers may be incentivised by low upfront cost without taking into account the long term costs.
Then there are batteries which last for longer periods, particularly as the energy requirements of circuitry falls. However, these batteries usually command a premium price.
Some of these issues can be dealt with in a few ways. Lack of end user knowledge about the capabilities of energy harvesting technologies and cost over time have to be addressed. There is a need for clear case studies of energy harvesting powered wireless sensors, showing payback versus others. End users are more likely to adopt the technology if it is proven rather than PowerPoint.
The widespread publicity of the internet of things will help to gain recognition for wireless sensors and how they can add value. Wireless sensors, forming part of the fabric of the internet of things, will increasingly use energy harvesting as a power source. IDTechEx sees the energy harvesting market by component reaching US$596 million in 2018, up from US$163 million in 2014.
By Raghu Das, CEO, IDTechEx