By Majeed Ahmad, Contributing Writer
Although questions may arise, such as where does
energy harvesting technology stand today and why is it
taking so long, the building blocks of an energy harvesting
system must be explained first before delving into this tech
wonderland and uncovering the stumbling blocks.
Energy Harvesting Building Blocks
Energy harvesting all starts with a device that extracts
and manages small amounts of power from photovoltaic,
piezoelectric, biochemical, thermal and
mechanical vibration sources. The solar
modules are most popular, because they are
readily available. There are also piezoelectric
and electromagnetic devices that generate
power from kinetic energy sources like
The second key building block is a power
management IC that receives the lowest
amount of power generated by the energy-
harvesting device, and transforms that energy
for storage in devices, such as batteries or a
supercapacitor. The power management IC
also handles the outflow of power from the
storage device to ensure power is not being drawn when
the stored energy is below a value of threshold.
The storage device in an energy-harvesting design—
battery, conventional capacitor, supercapacitor, etc.—is
connected to the rest of the system to provide the
necessary power in order to operate an energy-harvesting
application like a wireless sensor network.
Now, it is time to take a closer look at how these basic
building blocks (Figure 1) work in tandem and what is
actually hindering the potential of this technology.
New Design Challenges
For a start, it is worth acknowledging that energy harvesting
systems have proved far more complicated than originally
anticipated, mostly because of the issues related to power
management and thermal management. Energy harvesting
has added new design challenges of its own, for instance,
the need for batteries that can operate for years without
Available batteries are typically undesirable due to
size, cost, and reliability issues. In other words, energy-
harvesting applications are not feasible with traditional
battery-powered systems. The actual adoption has also
Energy harvesting has been resonating in the industry circle as a technology fairytale
for many years now. This environmental-friendly
undertaking, that derives energy from external
sources, thrusts on the industry scene with the
promise of reducing our reliance on batteries.
With a conservative approach toward power
management, energy harvesting has been seen
as revolutionizing many segments, ranging from
home automation to wireless sensor networks
and smart lighting.
Despite battery issues, the IoT juggernaut is
helping reinvent this promising technology
Figure 1: The block diagram showing key ingredients of an energy-harvesting system.
(Source: Analog Devices)