Page 14 - PEN eBook October 2025

DESIGN
Implementing Energy
Harvesting in Smart
Building IoT Systems
IoT devices play a crucial role in reducing the
environmental impact of commercial and residential
buildings, and this sector represents a significant growth
opportunity for electronics system OEMs. However,
their increased use is having unintended environmental
consequences with battery wastage from IoT devices
now attracting the attention of legislatures. This article
highlights advances in energy-harvesting technologies
and examines how OEMs can stay ahead of potential
incoming legislation through their implementation in
smart building and home IoT systems.
By Bruno Damien, ecosystem marketing director at e-peas
Residential and commercial buildings account for legislation across most major economies to improve
almost one-third (31%) of all emitted greenhouse gases the efficiency of buildings. Further legislation exists
in the U.S. In Europe, this figure is slightly higher, at
over one-third. As such, there has been a spate of such as air quality rules.
14 OCTOBER 2025 | www.powerelectronicsnews.com
across a wide range of other building specifications,
DESIGN
IoT systems play a pivotal role in helping to meet explained in a recent webinar entitled “Ambient IoT
these stipulations, with grants and incentives, such as viewed from the storage element side.”
the U.S.’s Inflation Reduction Act and Europe’s ELENA
grant facility, available to help meet the costs of Capital expenditures are also important in a facility
upgrading buildings to standard. manager’s decision, and recent years have seen
efficiency/technical advances in solar, piezo, and
IoT DEVICES’ ENVIRONMENTAL thermal harvesters as well as in power management
IMPACT IS ATTRACTING ICs (PMICs) and MCUs for energy-harvesting systems
LEGISLATIVE ATTENTION that reduce the cost of implementing them, with it now
It’s therefore unfortunate that the nature of IoT being cheaper to develop an
systems means many of these devices are causing energy-harvesting-based IoT systems than it is to
an unintended environmental issue, with disposable develop one based on AA batteries.
batteries entering landfills in huge numbers.
And while they are not yet at a parity with a
These devices may be marketed as being able to run coin-cell-based system (e.g., CR2032), they are within
for several years on a single or dual AA battery/coin the “sustainable premium” that both consumers and
cell, but research by the EU estimates that tens of B2B customers are willing to pay.
millions of batteries from IoT devices are discarded Cisco suggests people are willing to spend significantly
every day, with a positioning paper looking at ways to
Research by Simon-Kucher & Partners as well as
reduce this.
devices they power” and highlights that the average more for sustainable products and services. These
The paper seeks to “make batteries outlive the IoT
studies place this premium in the region of 20% to
25%. Research by Deloitte has also recorded this
IoT device requires over five battery changes in its effect in B2B customers, with those surveyed being
1.7× more likely to pay a premium and 2.7× more likely
operational life. Additionally, it stresses the need for
to make long-term commitments to suppliers with
IoT device OEMs to “think about power at the early
conceptual stages of IoT solutions … understanding sustainable product options.
the operating environment and what types of energies HOW TO IMPLEMENT ENERGY
could be harvested and stored.”
Smart building IoT devices cover a huge number of HARVESTING TO POWER IoT DEVICES
functions, from temperature, air quality, and other Assess the available power budget
While not every IoT application is well-suited to using
environmental sensors to security, water management,
and even smart mouse traps. The market is already ambient energy, a significant proportion of IoT devices
run on milliwatts (or even hundreds of microwatts)
worth $108 billion and is set to grow at a compound
annual growth rate of 28.5% to reach over and operate in environments where at least one
energy source will be available to meet the specific
$570 billion by 2030. Which means it’s only a matter
of time until the positioning paper is enacted, with a needs of an application. And even for higher-power
need to replace primary non-rechargeable batteries
with energy harvesting, backed up by secondary energy
storage (capacitors/rechargeable cells).
THE BENEFIT OF IMPLEMENTING
ENERGY HARVESTING FOR IoT
Before we get to how to implement energy harvesting,
it is important to note that there is a benefit in doing
so even before legislation is announced.
Not only does it keep you ahead of legislation, but
facility managers are paying increased attention to
the operational expenditures (opex) of checking and
replacing batteries in these systems, and the total
cost of ownership (TCO) of energy-harvesting-based
systems is considerably lower than battery-based
ones. Indeed, these reduce opex for facility managers Figure 1: PV cell characteristics and AEM behavior for
open-circuit ratio (left) and constant voltage tracking (right)
by up to 80% and TCO by between 30% and 50%, as maximum power-point tracking methods
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