Charging Electric Vehicles in Motion

Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

See omnystudio.com/listener for privacy information.

Episode Transcript

Speaker 1 (00:03):
In late October, the Economists published an article titled it
is now practical to refuel electric vehicles through thin air?
How is that possible? I'm Jonathan Strickland, and this is
tech Stuff Daily. One of the challenges facing electric vehicle
manufacturers is the public perception that battery power goes hand

(00:25):
in hand with limitations, specifically in the form of travel
distance on a single charge. If you've got a battery
full of juice and take off on a road trip,
what happens when you start creeping up on that last
bit of energy left in the battery. You might find
a charging station, but how long will it take you
to get your battery back up to speed. Gas powered
vehicles are easy to refuel. It takes a few minutes

(00:48):
and then you're back on the road, But most electric
vehicles require hours of recharging. That's not a big deal
if you're using your car for basic commutes and you
can recharge at the end of each day, But for
road trips, what are your solutions? One route is to
create fast charging stations. Tesla, which helped propel electric vehicles
into the mainstream consciousness, touts its supercharger stations as the

(01:09):
world's fastest. According to the company, you can get your
vehicle up to a full charge in just half an
hour using a supercharge station. Tesla has even created a
program in which Models and Model X owners get credits
equivalent to a thousand miles of travel on supercharge refills
every year. The company also states that if you were
to use up all your credits in a year, you'd

(01:30):
still only pay a fraction of the cost of filling
up a tank of gas at a supercharging station. Still,
half an hour of white time is too long for
some people, and the only other option is to swap
out batteries in some sort of pit stop. Right, not quite.
There's another solution that doesn't require cables or supercharging stations,
and the right implementation, it doesn't even require a driver

(01:51):
to stop his or her vehicle to charge. The secret
to this sorcery is inductive coupling. The idea is not new.
Michael Faraday got the basic idea back in the mid
nineteenth century. It all has to do with electromagnetism. Basically,
the relationship goes like this. If you take a conductive
material such as some insulated copper wire, and you move

(02:13):
that material through a magnetic field. The magnetic field will
induce a current to flow through the copper wire. To
make this a persistent effect, you either must continuously move
the copper wire in and out of the magnetic field,
or cause the magnetic field itself to fluctuate. In other words,
a steady magnetic field will only induce current to flow
through a conductor when the conductor initially enters that field.

(02:35):
There are different ways to cause a magnetic field to fluctuate.
One is to use an electro magnet with an alternating current.
Electromagnets generally consist of a conductive material, such as copper
wrapped around a fare right core. You may have made
a basic electro magnet in class by wrapping a copper
wire around an iron nail. Running a current through the
copper wire by attaching it to a battery turns it

(02:57):
into a magnet. Batteries provide direct current. However, if you
attach an electromagnet to a source of alternating current, the
electricity will flow one direction in the wire before reversing
and going the other direction. It will do this thousands
of times per second. The magnetic field will change as
the direction of electricity flow changes. While you have yourself

(03:17):
a fluctuating magnetic field. Now, imagine you take a bunch
of conductive copper wire and you create a pad that
can go on the bottom of an electric vehicle. When
that copper wire encounters a fluctuating magnetic field, it will
cause current to flow through the wire. Attach that wire
to your electric vehicles battery system, and the battery can
store that electricity. Generally speaking, the way this could work

(03:39):
for cars requires a lot of work. You need to
install the electro magnets and power systems under the surface
of the street. That usually means digging up existing streets
to lay down the technology and cover it back up
with asphalt. A basic implementation of this technology might only
exist at intersections or special parking spaces where a car
could spend some time idle. Any vehicle outfited with the

(04:01):
proper charging apparatus could benefit from such a system. This
would extend the range of any electric vehicle. If you
wanted to make your system to work with cars that
are actually in motion, you need to cover a lot
more ground. A car traveling at a good speed won't
spend enough time over any small segment like an intersection
to benefit very much. Instead, you need to outfit hundreds
of feet of street with these electro magnets so that

(04:23):
the electric vehicles traveling down the stretch could get enough
of a jolt of juice to make a difference. There
are some big barriers to implementing this sort of strategy,
namely time and money. Road construction can take a long
time and tends to be extremely disruptive while it's happening,
and it isn't necessarily the cheapest of activities, But once installed,
such an infrastructure could be an enormous benefit to electric

(04:46):
vehicle drivers. We may see these systems put in place
in a few different parts of the world. There are
research projects in Israel and France that are exploring opportunities
that would allow electric vehicle drivers to charge on the go.
Stationary solutions are popping up as well. They might require
someone to stop for a few minutes over a specific
stretch of pavement, but that is still more convenient than

(05:06):
having to plug a vehicle in with a physical cable.
This coupling strategy is an effective way to transmit power
over short distances, but even relying upon advanced technologies that
pair resonating components to boost efficiency and range, there are
limitations to this approach. We're not likely to see Nicola
Tesla inspired towers broadcasting power across miles. It's just not

(05:27):
a practical or efficient means to transmit power. But it
might end up removing one of the reservations some people
have about electric vehicles. To learn more about electro magnets,
electric cars, and all things technological, subscribe to the tech
Stuff podcast. We explore tech in greater detail. Over there,
I'll see you against him.