Speaker 1: In late October, the Economists published an article titled it
Speaker 1: is now practical to refuel electric vehicles through thin air?
Speaker 1: How is that possible? I'm Jonathan Strickland, and this is
Speaker 1: tech Stuff Daily. One of the challenges facing electric vehicle
Speaker 1: manufacturers is the public perception that battery power goes hand
Speaker 1: in hand with limitations, specifically in the form of travel
Speaker 1: distance on a single charge. If you've got a battery
Speaker 1: full of juice and take off on a road trip,
Speaker 1: what happens when you start creeping up on that last
Speaker 1: bit of energy left in the battery. You might find
Speaker 1: a charging station, but how long will it take you
Speaker 1: to get your battery back up to speed. Gas powered
Speaker 1: vehicles are easy to refuel. It takes a few minutes
Speaker 1: and then you're back on the road, But most electric
Speaker 1: vehicles require hours of recharging. That's not a big deal
Speaker 1: if you're using your car for basic commutes and you
Speaker 1: can recharge at the end of each day, But for
Speaker 1: road trips, what are your solutions? One route is to
Speaker 1: create fast charging stations. Tesla, which helped propel electric vehicles
Speaker 1: into the mainstream consciousness, touts its supercharger stations as the
Speaker 1: world's fastest. According to the company, you can get your
Speaker 1: vehicle up to a full charge in just half an
Speaker 1: hour using a supercharge station. Tesla has even created a
Speaker 1: program in which Models and Model X owners get credits
Speaker 1: equivalent to a thousand miles of travel on supercharge refills
Speaker 1: every year. The company also states that if you were
Speaker 1: to use up all your credits in a year, you'd
Speaker 1: still only pay a fraction of the cost of filling
Speaker 1: up a tank of gas at a supercharging station. Still,
Speaker 1: half an hour of white time is too long for
Speaker 1: some people, and the only other option is to swap
Speaker 1: out batteries in some sort of pit stop. Right, not quite.
Speaker 1: There's another solution that doesn't require cables or supercharging stations,
Speaker 1: and the right implementation, it doesn't even require a driver
Speaker 1: to stop his or her vehicle to charge. The secret
Speaker 1: to this sorcery is inductive coupling. The idea is not new.
Speaker 1: Michael Faraday got the basic idea back in the mid
Speaker 1: nineteenth century. It all has to do with electromagnetism. Basically,
Speaker 1: the relationship goes like this. If you take a conductive
Speaker 1: material such as some insulated copper wire, and you move
Speaker 1: that material through a magnetic field. The magnetic field will
Speaker 1: induce a current to flow through the copper wire. To
Speaker 1: make this a persistent effect, you either must continuously move
Speaker 1: the copper wire in and out of the magnetic field,
Speaker 1: or cause the magnetic field itself to fluctuate. In other words,
Speaker 1: a steady magnetic field will only induce current to flow
Speaker 1: through a conductor when the conductor initially enters that field.
Speaker 1: There are different ways to cause a magnetic field to fluctuate.
Speaker 1: One is to use an electro magnet with an alternating current.
Speaker 1: Electromagnets generally consist of a conductive material, such as copper
Speaker 1: wrapped around a fare right core. You may have made
Speaker 1: a basic electro magnet in class by wrapping a copper
Speaker 1: wire around an iron nail. Running a current through the
Speaker 1: copper wire by attaching it to a battery turns it
Speaker 1: into a magnet. Batteries provide direct current. However, if you
Speaker 1: attach an electromagnet to a source of alternating current, the
Speaker 1: electricity will flow one direction in the wire before reversing
Speaker 1: and going the other direction. It will do this thousands
Speaker 1: of times per second. The magnetic field will change as
Speaker 1: the direction of electricity flow changes. While you have yourself
Speaker 1: a fluctuating magnetic field. Now, imagine you take a bunch
Speaker 1: of conductive copper wire and you create a pad that
Speaker 1: can go on the bottom of an electric vehicle. When
Speaker 1: that copper wire encounters a fluctuating magnetic field, it will
Speaker 1: cause current to flow through the wire. Attach that wire
Speaker 1: to your electric vehicles battery system, and the battery can
Speaker 1: store that electricity. Generally speaking, the way this could work
Speaker 1: for cars requires a lot of work. You need to
Speaker 1: install the electro magnets and power systems under the surface
Speaker 1: of the street. That usually means digging up existing streets
Speaker 1: to lay down the technology and cover it back up
Speaker 1: with asphalt. A basic implementation of this technology might only
Speaker 1: exist at intersections or special parking spaces where a car
Speaker 1: could spend some time idle. Any vehicle outfited with the
Speaker 1: proper charging apparatus could benefit from such a system. This
Speaker 1: would extend the range of any electric vehicle. If you
Speaker 1: wanted to make your system to work with cars that
Speaker 1: are actually in motion, you need to cover a lot
Speaker 1: more ground. A car traveling at a good speed won't
Speaker 1: spend enough time over any small segment like an intersection
Speaker 1: to benefit very much. Instead, you need to outfit hundreds
Speaker 1: of feet of street with these electro magnets so that
Speaker 1: the electric vehicles traveling down the stretch could get enough
Speaker 1: of a jolt of juice to make a difference. There
Speaker 1: are some big barriers to implementing this sort of strategy,
Speaker 1: namely time and money. Road construction can take a long
Speaker 1: time and tends to be extremely disruptive while it's happening,
Speaker 1: and it isn't necessarily the cheapest of activities, But once installed,
Speaker 1: such an infrastructure could be an enormous benefit to electric
Speaker 1: vehicle drivers. We may see these systems put in place
Speaker 1: in a few different parts of the world. There are
Speaker 1: research projects in Israel and France that are exploring opportunities
Speaker 1: that would allow electric vehicle drivers to charge on the go.
Speaker 1: Stationary solutions are popping up as well. They might require
Speaker 1: someone to stop for a few minutes over a specific
Speaker 1: stretch of pavement, but that is still more convenient than
Speaker 1: having to plug a vehicle in with a physical cable.
Speaker 1: This coupling strategy is an effective way to transmit power
Speaker 1: over short distances, but even relying upon advanced technologies that
Speaker 1: pair resonating components to boost efficiency and range, there are
Speaker 1: limitations to this approach. We're not likely to see Nicola
Speaker 1: Tesla inspired towers broadcasting power across miles. It's just not
Speaker 1: a practical or efficient means to transmit power. But it
Speaker 1: might end up removing one of the reservations some people
Speaker 1: have about electric vehicles. To learn more about electro magnets,
Speaker 1: electric cars, and all things technological, subscribe to the tech
Speaker 1: Stuff podcast. We explore tech in greater detail. Over there,
Speaker 1: I'll see you against him.