Japanese scientists explore electric roads for EVs

Sep 20, 2011 by Nancy Owano report
A schematic of the proposed power transfer system. This system transmits electric power thorough a capacitor composed of a steel belt and a metal plate attached to the road, and the power feed in differential mode.

(PhysOrg.com) -- Masahiro Hanazawa of Toyota Central R&D Labs and Takashi Ohira from Toyohashi University are working on a solution for avoiding battery recharge headaches in powering electric cars. They are working on a prototype of electric cars that are powered by the road itself--electric roads for electric cars. While the idea of cars powered from the ground is not new, the system that they propose is an interesting way to power electric cars as the cars travel along the road through steel belts placed inside tires and a metal plate in the road.

This is how the Toyohashi University newsletter report describes their system:

"The source of energy from power lines is up-converted into radio frequency (RF) by high-speed inverters implanted along tracks in the road. The RF voltage is applied to a balanced metal track embedded under the surface of the road. The EV picks up the RF voltage via electrical capacitance between the metal and a steel belt installed inside of the tires of the EV."

In their experiments, the researchers put small metal plates on the floor and inside a tire, and positioned another metal plate above the tire. They measured the electrical impedance between the two plates. The team presented their work in May at the International Microwave Workshop Series on Innovative Wireless Power Transmission in Kyoto, Japan. While their tests involved low voltages, the researchers believe energy transfer from the to a running automobile is feasible. With enough power the system could run typical passenger cars, says Ohira.

Their system would require smaller battery packs, rather than heavier packs, to get back and forth from electrified highways, which is viewed as a benefit as well.

The proposed model and measurement model. As a the measurement model a metallic board were arranged above and below the tire, and the complex impedance was measured. Pieces of styrene foam of different thickness were placed between the upper surface of the tire and metallic plate. The measurement frequency was from 10 kHz to 10 MHz.

Still, outsider reactions to their news have been peppered with concerns. One concern is how much danger to the public might their system impose, for example, in someone stepping on an electrified metal strip. Another question being voiced is cost and infrastructure, considering the expanses of roads that would be dug up to accommodate the system.

An effort to explore the powering of EVs from the ground up was also reported earlier this year in Business Spectator Researchers at the Energy Dynamics Laboratory at Utah State University, said the report, were working on a solution where EVs could pick up small amounts of electricity as they drive over charging pads buried under the asphalt that are connected to the electrical grid.

Explore further: After nuclear phase-out, Germany debates scrapping coal

More information: www.tut.ac.jp/english/newslett… overtures/index.html

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Eikka
1 / 5 (1) Sep 20, 2011
At the power levels involved in driving a car, this system greatly resembles the devices I have seen used to cure the bonding resin in laminated wood.

They put the wood between the plates of a large capacitor and apply RF-voltage in the MHz range to it, and the dielectric losses in the wood cause the glue to heat up. Putting your hand in there, without touching either metal plate, would still be like putting your hand in a running microwave oven, and any electrical device more complex than a cordless drill tends to go absolutely bonkers near it.

It's a nice idea, because the metal plates can technically be buried in the road, but any time you transfer such large amounts of power wirelessly, you have to think of what happens to the power that is lost on the way.
Eikka
1 / 5 (1) Sep 20, 2011
Plus, you have to think about what is the capacitance between the strips of metal in the road over a hundred kilometers of it.

Unless you want to realize too late that it takes megawatts just to power the road without any cars on it.

And what happens if somebody drags a wire across the road to short it out?
Noumenon
4.7 / 5 (49) Sep 20, 2011
Reminds me of the self driving cars that engineering students learn eventually will never become practical, that's been tossed around for over 30 years.

Hey, I had this idea to construct gas filled troughs along the highway,... then cars would have a syphoning hose hanging down as they drive,... but too many gas stations killed the idea damit (sarcasm),.. so I think charging stations, and swapping out ready charged battery packs will kill this idea.
Bob_Kob
not rated yet Sep 20, 2011
Electric vehicles powered by room temperature superconducting magnetic batteries.
Sancho
5 / 5 (3) Sep 20, 2011
Reminds me of the old story of the beneficent king who wanted to pave the roads with leather; shown the impracticality of this, he opted to give his people shoes. ... The proper way to electrify the road is to make the "road" an ultra-light rail system open to dual-mode vehicles (cars that can operate on rail or road). In addition to their many other advantages, dual-mode vehicles would preclude the need for hare-brained schemes such as the one presented in this article.

lengould100
not rated yet Sep 20, 2011
Sancho nailed it.

Electrified public-access roads have too many problems. Primary one is "how to bill the cars?" and "who pays for it all?" The issues in there alone will keep this system offline forever, even if the transmission were acceptably efficient.
dnatwork
not rated yet Sep 20, 2011
Plus, you have to think about what is the capacitance between the strips of metal in the road over a hundred kilometers of it.

Unless you want to realize too late that it takes megawatts just to power the road without any cars on it.

And what happens if somebody drags a wire across the road to short it out?


What if you also embed some pressure sensors, so the transmitters are activated only directly in front of the car as it rolls down the road. Pair them with an RFID chip in the car, so the system is activated only if you have a car that identifies itself as needing power.

And it doesn't need to be buried. Fabricate it as a mat that you roll out on to existing roadways. Even dirt roads could support something like that.
El_Nose
1 / 5 (1) Sep 20, 2011
forget billing the cars -- tax payers pay for it -- come on -- there are more practical issues with this

1) roads have to be repaved every 5 yrs or so
2) trucks with hazardous waste in a collision could spill acidic or super basic liquids on roads and eat away at this and cause other issues
3) eventually people will never charge their car at home - knowing that the road will recharge their car for them -- one power outage and you strand an entire community
4) the list goes on and on ... but mainly without a super efficient energy source that is really really cheap this is not going to happen anytime soon, but if room temp superconducting wires are discovered tomorrow then I am all for it
Fionn
not rated yet Sep 20, 2011
Why not Tesla coils?
RBrandes
not rated yet Sep 20, 2011
Reminds me of the self driving cars that engineering students learn eventually will never become practical, that's been tossed around for over 30 years.


You have seen the Google fleet that has logged over 100,000 miles of self driving on actual roads right?
Noumenon
4.8 / 5 (45) Sep 20, 2011
Reminds me of the self driving cars that engineering students learn eventually will never become practical, that's been tossed around for over 30 years.


You have seen the Google fleet that has logged over 100,000 miles of self driving on actual roads right?


Yes, but that does not in any way demonstrate that it's practical on a mass scale for realizes. It's a impractical solution to a non-problem.
jimmie
not rated yet Sep 20, 2011
nou,

not impractical,

these new technologies are going to eat Teamsters.

jr
TheGhostofOtto1923
1 / 5 (1) Sep 20, 2011
Sancho nailed it.

Electrified public-access roads have too many problems. Primary one is "how to bill the cars?"
Vehicles and most other machines will soon be connected and independently conversing via the internet. They will be able to report their own usage and incidentally be taxed DIRECTLY for wear and tear on the infrastructure much more accurately and honestly and cleanly than it is currently done.

This would in effect operate like Onstar security/communication system and EZ-Pass toll system, recording speed, location with GPS, time, etc in conjunction with service records and condition of the vehicle.

Insurance discounts and surcharges will for all practical purposes make elements of this mandatory. Billing and automatic revenue deduction for electricity consumption will therefore be easy.
and "who pays for it all?"
Who pays for all those cell phone towers? No reason it cant be privatized.
TheGhostofOtto1923
1 / 5 (1) Sep 20, 2011
Yes, but that does not in any way demonstrate that it's practical on a mass scale for realizes. It's a impractical solution
At present.
to a non-problem.
The intractable problem of overloaded highway systems and limited room for expansion, which are critical NOW, can be eased by higher densities enabled by self-driving vehicles. Accidents will be reduced when cars are constantly monitoring their environment, and communicating with other vehicles and traffic control.

Oh hey look what just popped up:
http://www.physor...lin.html

-Imagine this in conjunction with a centralized traffic control system which took charge of routing within cities, and the vehicles controlled their interaction with the immediate environment?
PS3
1 / 5 (1) Sep 20, 2011
Charging by using the shock springs will be the best.
alternaverse
not rated yet Sep 20, 2011
I wrote an article based on this idea and expanded it further. It's posted on my G account if anyone wants to read it. tinyurl.com/4334hsx
Parsec
not rated yet Sep 21, 2011
There are now wireless electrical transmission systems based on high frequency magnetic resonance that can easily transmit large amounts of power with about 70% efficiency from 30 to 60 feet. So just put in these stations about every 10 feet and as the cars run by them the car gets charged.

Obviously a LOT more work would have to be put into systems that are doling out kilowatts of energy every few seconds, but that's probably solvable.

As to who to bill for them, using a wireless ID system would easily solve that problem.
SR71BlackBird
not rated yet Sep 21, 2011
Reminds me of the self driving cars that engineering students learn eventually will never become practical, that's been tossed around for over 30 years.


I'd like to navigate you towards another article recently posted about an autonomous car that is currently driving through the streets of Berlin. http://www.physor...lin.html

I believe its people like you that hinder technological progress. Open your mind.

"The true sign of intelligence is not knowledge but imagination" - Albert Einstein
aljobo
not rated yet Sep 21, 2011
Transport needs to be decarbonized. To get there massive investment will be required. Current battery technology is still way off in terms of cost, power density and charging time, all of which will delay the widespread adoption of EVs. Trucks are even further off as they constantly need to cover large distances and have much greater power requirements.
Given the massive investment required its worth thinking outside the box. Digging up the road doesnt need to mean massive road works everywhere. Only two narrow strips of metal need to be laid an inch deep, which could be done quite cheaply and quickly. Dont forget the massive infrastructure that brings liquid fuels from oil wells into cars: hundreds of billions are spent on liquid fuels every year so investments in the tens of billions could still easily produce savings for everyone. Autonomous driving is just a nice bonus.
In Germany Charly Schorr is working on this concept so watch this space.

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