Page 36 - EE Times Europe Magazine – November 2023

36 EE|Times EUROPE

OPINION | GREENER ELECTRONICS | ENERGY HARVESTING

What’s Happening in the THE MICRO ENERGY–HARVESTING

World of Micro-Energy SYSTEM
A micro-energy–harvesting system
comprises the harvester or harvesters,
Harvesting? an energy-harvesting power manage-
ment integrated circuit (EH PMIC) and
an energy storage component—usually a
capacitor—that delivers stored energy to
By Huw Davies, Trameto the load when the EH PMIC instructs it to
do so.
The goal of micro-energy harvesting
Micro-energy–harvesting systems that deliver anything from is to eliminate batteries, particularly in
a few hundred microwatts to a few milliwatts of power on demand the billions of IoT devices deployed in
have been in development for at least the last couple of decades. industrial automation, predictive main-
Today, the market could still be described as nascent, even though tenance, agriculture, security, healthcare,
the technology promises to mitigate or eliminate the heavy eco- transportation, construction, smart homes
nomic and environmental costs of batteries in IoT devices. There and a host of other applications. But in
are relatively few such devices in which micro-energy harvesting is many applications, it may be sufficient to
deployed, but a confluence of developments looks set to change this. complement battery power, extending the
First, the world is now far more sensitive to environmental issues operating lifetime of a device so that bat-
than at any time in the past. Large-scale energy harvesting is seen everywhere, with solar farms, teries rarely, if ever, need to be replaced.
wind turbines and hydropower contributing to an ever-greater proportion of our energy usage. The less accessible the IoT device, the
There’s a trickle-down effect that is driving greater interest and credibility in micro-energy more expensive it is to replace batteries,
harvesting. so micro-energy harvesting may enable
Second, the energy consumption of the processors (usually microcontrollers) and wireless new applications in remote locations that
connectivity systems within IoT devices continues to fall. Shrinking process nodes in chips, would previously have been uneconomical.
the emergence of sub-threshold devices and smarter management of on-chip resources are all The challenge for IoT device design-
contributory factors. ers who are interested in micro-energy
Third, micro-energy–harvesting systems are becoming more effective, more efficient and, harvesting is that the available sources of
crucially, cheaper to implement. It now takes far less time to achieve a return on investment renewable energy may not be known at the
from such systems. outset.

IMAGE: SHUTTERSTOCK

NOVEMBER 2023 | www.eetimes.eu