POWER January 2020 - 48

TECHNOLOGY
displays, and medical implants. "
■ Carnegie Mellon scientists " have developed
a new method for creating highly
flexible, tattoo-like circuits that could
one day power wearable devices. "
■ German researchers have created
" next-generation metal-air batteries,
which can be easily fabricated into
flexible and wristband-like cells. "
■ Massachusetts Institute of Technology
researchers " have developed a new
system to power and communicate
with devices implanted deep into the
human body. "
■ Penn State University investigators
have come up with a " wearable piezoelectric
energy harvester " that can
generate power from movement such
as walking and jogging that could produce
power for a personal health monitoring
system. Piezoelectricity is the
phenomenon that certain materials can
generate an electric charge as a result
of an applied mechanical stress. The
best example is the burner igniters on
many natural gas kitchen stoves.
■ A major Japanese printing company
has come up with an " electric paper
display, " which they claim " can be
used to generate a display on batteryfree
Internet of Things devices compliant
with the EnOcean standard. "
EnOcean, according to Wikipedia, " is
an energy harvesting wireless technology
used primarily in building automation
systems, and is also applied
to other applications in industry, transportation,
logistics and smart homes. "
Wearable Technologies exhibited at
this November's MEDICA trade show
in Dusseldorf, Germany, in a joint pavilion
where exhibitors were " showcasing
which latest innovations and developments
are available on the market today
and which ones will become a part of our
everyday life in the near future. "
Where will wearable power technologies
fit into everyday life in the future?
A 2016 Frost & Sullivan analysis,
" Wearable Technologies in Clinical and
Consumer Health, " suggests that the
short-term future is in medicine. The report
predicts a global market of $18.9
billion in 2020. That prediction does
not focus entirely on wearable power
in medicine, but includes " devices that
can detect, store, and transmit vital parameters
(such as heart rate, oxygen
saturation, respiratory rate) measured
in real time to report the overcoming of
certain critical thresholds. " Many such
devices are already in use, most often
January 2020 | POWER
powered by external batteries, not by
kinetic or biological forces.
The Roots of Wearable Power
Wearable power has a long history, going
back to the 1970s and the advent
of
solar
photovoltaic-powered
wrist
watches. The Japanese watch company
Seiko was a pioneer, introducing a solarpowered
watch in 1978-the LCD Solar
Alarm Chronograph A156-5000. Since
then, other watchmakers have offered
solar-powered models, using a small solar
panel to charge an onboard battery.
Today, solar-powered watches are widely
available, often at a price of about $100.
In early 2008, The New York Times
" Taking
carried an article headlined
People Power to a New Level. " Somewhat
breathlessly, building on an article
in the American Association for the Advancement
of Science journal Science,
the piece proclaimed, " Some people
exercise by power walking. But what if
walking could actually provide electrical
power? Researchers have developed
an electrical generator mounted on the
knee that turns walks into watts. "
Mobile, Not Wearable
Another approach to power from the people
is produced in our moving technologies.
Not large mobile power generators
provided by a number of manufacturers
but personal transportable power.
The most common example is regenerative
braking, used in millions of
electric vehicles, growing in popularity
around the world. This technology
converts the kinetic energy when you
apply the brakes to slow your vehicle
into useable electric power that can be
stored onboard or routed to the electric
motor. Otherwise, as has been the case
for more than a century, the energy from
braking is lost as heat.
When it comes to mobile power generation,
solar appears to be the current best
bet, particularly on tractor-trailer trucks.
Last year, the North American Council for
Freight Efficiency issued a report, " Solar
for Trucks and Trailers, " that concludes,
" Solar panels have applications both on
the tractor and the trailer. The roof fairing
of the tractor has historically gone unused
and has ideal access to sunlight. The main
uses of solar on tractors are to supplement
battery [heating, ventilation, and
air conditioning] systems and hotel loads
without adding additional batteries. "
The truck industry group noted, " The
fuel costs faced by the trucking industry
are a significant part of the expense to
www.powermag.com
2. Mounting solar PV panels on tractor-trailer
trucks and RVs is an innovative way to supplement
power needs. The systems are generally
not capable of supplying all loads, but can help
to extend the availability of battery systems.
Source: Flickr / RVwithTito
operate a tractor-trailer in North America.
Over the past decade, fuel has been as
high as $0.65 per mile driven and then
dropped to $0.34 by 2016. At these two
points, fuel costs accounted for 39% and
21% of the total cost of operating a commercial
vehicle, respectively. "
The group's report adds, " Interest
in solar panels is growing among fleet
managers because truck batteries are
often no longer able to meet the power
needs of today's trucks due to increased
driver comfort demands, idle reduction
regulations, and increased tracking requirements.
However, because solar
photovoltaic (PV) panels are so new to
the trucking industry, many are unsure
how to calculate payback when considering
investing. "
Other mobile solar technologies are
readily available, although less promising
in scale than trucking applications. The
most common are smaller-scale portable
solar arrays for recreational vehicles
(RVs, Figure 2). The website solarpowerrocks.com
says, " If you travel often, and
to remote locations, an RV solar panel
will do wonders in terms of convenience
and cost savings. " The site suggests two
standard 100-W panels to keep an RV's
" deep-cycle batteries charged without
plugging into an external power source. "
In the meantime, Bionic Power is offering
its wearable generating technology
as a medical device to assist children
with mobility problems through a separate
spinoff company. CEO Garcha said,
" Imagine a condition where a kid can't
straighten the knees fully. " His technology
could help that child by boosting the
lift slowly, " lengthening the tendons to
help the child be able to walk. " The technology
will require U.S. Food and Drug
Administration approval, but according to
Garcha, it's going into clinical trials. ■
-Kennedy Maize is a long-time
energy journalist and a frequent
contributor to POWER.
47
http://www.rocks.com http://www.powermag.com
POWER January 2020

Table of Contents for the Digital Edition of POWER January 2020
