WIRELEss JUIcE: A PriMer
tEcH 1: Inductive coupling
Availability: April
>> the first Wireless Po Wering systeM to market is an induc-
tive device, much like the one Tesla saw in his dreams, but a lot
smaller. It looks like a mouse pad and can send power through
the air, over a distance of up to a few inches. A powered coil
inside that pad creates a magnetic field, which as Faraday pre-
dicted, induces current to flow through a small secondary coil
that’s built into any portable device, such as a flashlight, a
phone, or a Black Berry. The electrical current that then flows in
that secondary coil charges the device’s onboard rechargeable
battery. (That iPhone in your pocket has yet to be outfitted with
this tiny coil, but, as we’ll see, a number of companies are about
to introduce products that are.)
The practical benefit of this approach is huge. You can drop
any number of devices on the charging pad, and they will
recharge—wirelessly. No more tangle of power cables or jumble
of charging stations. What’s more, because you are invisible to
the magnetic fields created by the system, no electricity will
flow into you if you stray between device and pad. Nor are there
any exposed “hot” metal connections. And the pads are smart:
Their built-in coils are driven by integrated circuits, which
know if the device sitting on them is authorized to receive
power, or if it needs power at all. So you won’t charge your car
keys. Or overcharge your flashlight.
The dominant player in this technology for the moment seems
to be Michigan-based Fulton Innovation, which unveiled its first
set of wirelessly charged consumer products at the Consumer
Electronics Show early this year. Come April, Fulton’s new pad-
based eCoupled system will be available to police, fire-and-
rescue, and contractor fleets—an initial market of as many as
700,000 vehicles annually. The system is being integrated into a
truck console designed and produced by Leggett & Platt, a $4.3
billion commercial shelving giant; it allows users to charge any-
thing from a compatible rechargeable flashlight to a PDA. The
tools and other devices now in the pipeline at companies such as
Bosch, Energizer, and others will look just like their conventional
ancestors. Companies such as Philips Electronics, Olympus, and
Logitech will create a standard for products, from flashlights to
drills to cell phones to TV remotes, by the end of this year.
tEcH 2: Radio-frequency Harvesting
Availability: April
>> the induction systeMs are only the beginning. Some of the
most visually arresting examples of wireless electricity are based
on what’s known as radio frequency, or RF. While less efficient,
they work across distances of up to 85 feet. In these systems, elec-
tricity is transformed into radio waves, which are transmitted
across a room, then received by so-called power harvesters and
translated back into low-voltage direct current. Imagine smoke
detectors or clocks that never need their batteries replaced. Sound
trivial? Consider: Last November, to save on labor costs, General
Motors canceled the regularly scheduled battery replacement in
the 562 wall clocks at its Milford Proving Ground headquarters.
This technology is already being used by the Department of
Defense. This year, it will be available to consumers in the form of
a few small appliances and wireless sensors; down the road, it will
appear in wireless boxes into which you can toss any and all of
your electronics for recharging.
tEcH 3: magnetically coupled Resonance
Availability: 12–18 months
>> invented by Mit’s soljAcic (who has dubbed it WiTricity),
the technique can power an entire room, assuming the room is
filled with enabled devices. Though WiTricity uses two coils—
one powered, one not, just like eCoupled’s system—it differs
radically in the following way: Soljacic’s coils don’t have to be
{big, green, And juicy}
>> the MArket for Wireless electricity
has inventors and investors upbeat, even
in a down market. “this is going to be so
big I don’t think I can even get my arms
around the market impact,” says steve
Anderson, the senior vice president for
texas instruments’ power-management
group. Anderson’s crew is developing the
integrated circuits that manage the power
flow in wireless inductive power pads.
“this is a huge step,” he says.
With a huge upside. According to a
2006 department of energy study, more
than 700 million power-supply devices
88 Fast company February 2009
(chargers, charging stands, transformers,
and the like) will be sold in the u.s. in
2010, a $6 billion market. Worldwide, the
market runs to about $30 billion. “As far
as we can tell,” says Andrew fanara, the
team leader for the ePA’s energy star
Products group, “there are at least two
external power adapters in the world for
every man, woman, and child on the
planet—about 12-to- 15 billion of them.”
but wireless technology is not only
neater (say good-bye to the power-strip
Medusa under your office desk), it’s cleaner.
the ePA says Americans purchase a total
of 3 billion disposable dry-cell batteries
every year (part of a worldwide market of
about 15 billion) and then throw 2. 8 billion
of them into landfills. Wireless systems
are designed for rechargeable batteries
that can be reused hundreds of times
before they become trash.
And according to WiPower, inductive
charging systems work with about 80% to
90% efficiency—roughly the same as
plugging directly into a wall socket. that
blows away the industry average for wired
chargers, around 40%. so wireless juice is
not only less messy, it’s less hungry, too.
