The roads will soon charge your electric car – while you’re driving

The 2010 North American Auto Show. Image: Getty.

It was Tesla Motors, more than any other company, that triggered the current interest in electric cars. The firm’s namesake, Nikola Tesla, a genius inventor and Thomas Edison’s arch rival, would no doubt be pleased. Yet Tesla would be even more thrilled to realise the next step for electric vehicles involves turning his biggest vision into reality: the wireless transmission of power.

Due to their low local emissions, battery-powered electric cars are more in demand than ever, but they still have a reputation for being too expensive and having too short a driving range. So how about recharging them without having to plug in a cable, while parking or even driving on the road?

This isn’t science fiction: we know from our electric tooth brushes that batteries can be recharged without plugging in a wire, and even smart phones can be charged just by being placed on top of a pad.

Nikola Tesla planned – but never completed – a wireless power transmitter in New York. Frank R Paul & Joseph Riley, Transmitting Power by Radio (1925). Image: public domain.

Here’s how it works: an alternating current (AC) flows through a wire coil (the transmitter), which causes a magnetic field to switch between two directions at a high frequency. A second coil (the receiver) exposed to that magnetic fields picks up those oscillations, inducing an AC current in its own circuit, which is then used to power the car (or charges the battery in your toothbrush).

Electronic systems able to handle higher frequencies, which allow more power to be transmitted, are becoming more affordable. Energy can now be transferred between coils that are increasingly further apart or aren’t aligned accurately.

Thanks to this technology, some electric cars can already be charged by parking them on top of charging pads, which can be as much as 20cm away from the receiving coil at the bottom of the vehicle. The next step is to wire-up the roads themselves with coils so that cars, buses, and even trucks could be charged while they move.

For peace of mind, wireless charging systems are properly shielded so that no animals or humans will be harmed. A coil in the road will only emit power when it is in wireless communication with a receiver coil above it, and the latter will absorb nearly all of it. The bit that is lost is mostly absorbed by the metal body of the car itself.


The path to wired-up roads

Retrofitting roads with wireless charging coils sounds expensive. But recent studies show that the biggest part of the cost comes from the construction work itself – on a new or renovated road, the extra costs are not that high.

Charging on the move isn’t just a convenient time-saver – it will also bring down the cost of electric vehicles themselves. Batteries that get recharged more frequently during usage will last longer and can be made smaller while retaining the same driving range.

As with all new technologies that rely on not-yet existing infrastructure, wireless vehicle charging will start in a niche market (remember the early and expensive days of mobile phones?). In this case, the niche is electric buses that re-charge at bus stops and on certain segments of their fixed driving route.

The global pioneer is the Online Electric Vehicle (OLEV), a bus developed a few years ago by South Korea’s Advanced Institute of Science and Technology (KAIST). Continuous charging means OLEV buses cover their routes using small batteries just a third the size of those found in a regular electric car. More recently, Swedish truck and bus-maker Scania trialled a similar system of recharging stations for buses to demonstrate such technology could still work in harsh Nordic winters.

For passenger cars, wireless charging will first come as a convenience feature. People will be able to park in their driveway or garage without having to plug in a cable, and will still have a recharged battery next time they need the car.

We will have to wait longer for a dense network of highways that can charge vehicles on the move. This would be a major infrastructure investment and would involve a substantial quest for more copper wires and semiconductor components.

Experience with the technology and agreement on international compatibility standards will be prerequisites of such investments. Safety must not be ignored: the transmitter coils emit substantial power, which is only considered safe if it is in proper communication with a receiver coil. Communication between transmitter and receiver must also be secured against accidental or even intentional interference – an aspect that even touches on cyber security.

So when and where will we see electrified roads being rolled out on larger scale? Korea will try and maintain its leadership in this technology. Places like Singapore, wealthy and with strong ambitions in clean and efficient transport, may follow soon. Standardised electrified roads could become what the railways were to the 19th century: not only a leap in transport efficiency, but the core of a new industry.The Conversation

Harry Hoster is director of Energy Lancaster and professor of physical chemistry at Lancaster University.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Barnet council has decided a name for its new mainline station. Exciting!

Artist's impression of the new Brent Cross. Image: Hammerson.

I’ve ranted before about the horror of naming stations after the lines that they’re served by (screw you, City Thameslink). So, keeping things in perspective as ever, I’ve been quietly dreading the opening of the proposed new station in north London which has been going by the name of Brent Cross Thameslink.

I’ve been cheered, then, by the news that station wouldn’t be called that at all, but will instead go by the much better name Brent Cross West. It’s hardly the cancellation of Brexit, I’ll grant, but in 2017 I’ll take my relief wherever I can find it.

Some background on this. When the Brent Cross shopping centre opened besides the A406 North Circular Road in 1976, it was only the third large shopping mall to arrive in Britain, and the first in London. (The Elephant & Castle one was earlier, but smaller.) Four decades later, though, it’s decidedly titchy compared to newer, shinier malls such as those thrown up by Westfield – so for some years now, its owners, Hammerson, have wanted to extend the place.

That, through the vagaries of the planning process, got folded into a much bigger regeneration scheme, known as Brent Cross Cricklewood (because, basically, it extends that far). A new bigger shopping centre will be connected, via a green bridge over the A406, to another site to the south. There you’ll find a whole new town centre, 200 more shops, four parks, 4m square feet of offices space and 7,500 homes.

This is all obviously tremendously exciting, if you’re into shops and homes and offices and not into depressing, car-based industrial wastelands, which is what the area largely consists of at the moment.

The Brent Cross site. Image: Google.

One element of the new development is the new station, which’ll sit between Hendon and Cricklewood on the Thameslink route. New stations are almost as exciting as new shops/homes/offices, so on balance I'm pro.

What I’ve not been pro is the name. For a long time, the proposed station has been colloquially referred to as Brent Cross Thameslink, which annoys me for two reasons:

1) Route names make rubbish modifiers because what if the route name changes? And:

2) It’s confusing, because it’s nearly a mile from Brent Cross tube station. West Hampstead Thameslink (euch), by contrast, is right next to West Hampstead tube.

Various other names have been proposed for the station. In one newsletter, it was Brent Cross Parkway; on Wikipedia, it’s currently Brent Cross South, apparently through confusion about the name of the new town centre development.

This week, though, Barnet council quietly confirmed it’d be Brent Cross West:

Whilst the marketing and branding of BXS needs to be developed further, all parties agree that the station name should build upon the Brent Cross identity already established. Given the station is located to the west of Brent Cross, it is considered that the station should be named Brent Cross West. Network Rail have confirmed that this name is acceptable for operational purposes. Consequently, the Committee is asked to approve that the new station be named Brent Cross West.

Where the new station will appear on the map, marked by a silly red arrow. Image: TfL.

That will introduce another irritating anomaly to the map, giving the impression that the existing Brent Cross station is somehow more central than the new one, when in fact they’re either side of the development. And so:

Consideration has also been given as to whether to pursue a name change for the tube station from “Brent Cross” to “Brent Cross East”.

Which would sort of make sense, wouldn’t it? But alas:

However owing to the very high cost of changing maps and signage London-wide this is not currently being pursued.

This is probably for the best. Only a handful of tube stations have been renamed since 1950: the last was Shepherd’s Bush Market, which was until 2008 was simply Shepherd's Bush, despite being quite a long way from the Shepherd's Bush station on the Central line. That, to me, suggests that one of the two Bethnal Green stations might be a more plausible candidate for an early rename.


At any rate: it seems unlikely that TfL will be renaming its Brent Cross station to encourage more people to use the new national rail one any time soon. But at least it won’t be Brent Cross Thameslink.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason. 

Want more of this stuff? Follow CityMetric on Twitter or Facebook