Analysis: Energy harvesting holds out promise of ‘self-powered’ IoT
Energy harvesting promise self-powered IoT

Analysis: Energy harvesting holds out promise of ‘self-powered’ IoT

As we look forwards to 2018, energy harvesting technologies look set to solve one of IoT’s greatest challenges: power supply.

The millions of tiny sensors and meters that make up the IoT all need power. In many cases, they require batteries that must be purchased, maintained and disposed of if they are to continue to measure location, temperature, humidity, gas flow, vibration and so on in IoT applications ranging from smart buildings to precision agriculture. If predictions are correct, the number of sensors worldwide looks set race past the one trillion mark some time around 2020 – just two to three short years away.

But where wireless sensor terminals are deployed over wide areas and in remote locations, concerns over battery life and the costs associated with maintaining batteries can be a big concern, especially if it involves long journeys and fiddly replacement exercises.

Read more: How energy harvesting is powering the IoT

More harvesting, more efficiency

Energy harvesting technologies may provide a solution. These use power-generating elements such as solar cells, piezoelectric and thermoelectric elements to convert light, vibration and heat energy, respectively, into electricity.

The thinking behind energy harvesting is that it could help to extend battery life where batteries and energy harvesting are used together – or even circumvent the need for batteries entirely in certain wireless sensors. What’s vital is that the correct balance is struck between power generation and power consumption, in order to continuously deliver sufficient power to a sensor to keep it working on an ongoing basis.

According to a recent report from analyst company Markets & Markets, the energy harvesting system market is expected to more than double to $645.8 million in 2023, from $311.2 million in 2016.

Read more: UCSD engineers develop near-zero-power sensor for ‘unawearables’

Leading the field

EnOcean, a company based in Oberhaching, Germany, is a pioneer in this area and is planning to showcase its “self-powered wireless solutions” for the IoT at the Consumer Electronics Show (CES) in Las Vegas in the New Year.

Basically, the company produces sensors that rely on energy harvesting, rather than batteries, to collect and transmit data about their own state and the world around them in applications including building automation, smart homes, LED lighting control and industrial applications.

According to EnOcean CEO Andreas Schneider, “Maintenance-free sensor solutions based on open standards such as EnOcean and Bluetooth will significantly facilitate the transition to big data analytics and the Internet of Things.”

Elsewhere, UK-based Drayson Technologies has incorporated its Freevolt technology that scavenges radio frequency (RF) energy from cellular and WiFi transmissions – energy that is all around us, particularly in urban environments, but which usually goes to waste – in its Cleanspace tags for monitoring environmental pollution.

Energy harvesting technologies appear to have big potential. While there’s plenty of noise around the power-saving opportunities that the IoT promises, in terms of delivering more energy-efficient factories, vehicles and cities, far less attention is paid to its own energy consumption. If we are truly heading towards a ‘trillion-sensor economy’, as many suggest, then we need to ask some serious questions about what it will cost to power that economy.

Read more: Researchers create energy-efficient power converter for IoT