I got ridiculed for posting my thoughts on this before, but here goes... (induction roads)

[Bread and Circus]

http://www.huffingtonpost.com/2009/05/19/competition-heats-up-in-r_n_205027.html

Engineers at South Korea's top-ranked KAIST university are meanwhile working on a novel prototype for an electric vehicle system: one that provides power on the go through induction strips laid into the roadway.

...

Suh, an MIT-trained inventor with some 60 international patents to his name, approached the challenge from another angle.

"Why not have power transmitted on the ground and pick it up without using mechanical contact?" he said in an interview in his office overlooking the staging grounds for the university's electric cars.

KAIST's "online" vehicles pick up power from trips, or inverters, embedded into the road rather than transmitted through rails or overhead wires. A small battery, one-fifth the size of the bulky batteries typically used, would give the vehicle enough power for another 50 miles (80 kilometers), said Cho Dong-ho, the scientist in charge of the project.

South Korea produces its own nuclear power, meaning it can produce a continuous supply of energy to fuel such a plan.

President Lee Myung-bak, whose government gave KAIST $50 million for two major projects, including the "online" electric vehicle, took a spin in February.

Online buses are running at the KAIST campus and will begin test runs soon on the resort island of Jeju.

But Seoul, which has promised to set aside $2 million for the underground charging system, is within Suh's sights. He said 9,000 gasoline-fueled buses now crisscross the capital, with 1,000 going out of commission each year. He envisions replacing those aging buses with electric models. Initial test runs are expected to take place this year.

Mueller, the consultant, called it a creative approach with potential.

"It sounds very intriguing; you don't store your energy, you provide it on the go." he said. "The (battery) storage problem is overcome instantly. That would be a very intriguing way of doing it."


---------------------

So there, smarter and more educated people than me don't think it's worth dismissing out of hand.

As far as I'm concerned induction roads (and highways, especially powered by solar in the desert) are a bit of an electric transportation holy grail.

[pleah]

1. K&R I must have missed the earlier post.

:hi: Sounds really cool.

[Bread and Circus]

3. It was a while back and I was met w/ the usual "you can't do that" theorycrafting...

but I say....

YES WE CAN!

LOL.

[meegbear]

2. I didn't get a chance to ridicule you earlier ...

could you repost your thoughts?

[Bread and Circus]

4. basically I imagined an electric system that was a hybrid of

onboard batteries on vehicles w/ passive electrical assist via induction on select streets, roads, and highways. This is exactly what Suh is describing in the article.

It helps get around the limited range of electric vehicles and allows for the decentralized eletrification of vehicles.

Think of a highway in the western desert that had strips of providing induction electricity to cars and trucks via passive solar cells along the roadside. It wouldn't give you all the energy you needed to travel but it would offset some of the cost so that you could extend the range of your battery. So, Tesla roadster could go 600 miles on a charge instead of 275 ... or something like that.

Or think of San Francisco streets laden w/ induction electricity that allowed cars and buses to zip around without any overhead wires. Right now a lot of SF buses are electrically powered via overhead cables but can only go where the wires are. Batteries backed up by induction get around that.

I got the idea from my toothbrush (which is charged by induction) and reading up on Tesla himself, who invented the technology.

If only he were alive today. His genius is nearly beyond comprehension.

The response was that you can't efficient transmit enough energy at safe voltages, blah, blah, blah....

However w/ induction roads, you could charge your car even when you park...even without having to plug in necessarily.

Anyway...I'm sure it'd be expensive. But what isn't?

[GKirk]

6. "Anyway...I'm sure it'd be expensive. But what isn't?"

And there is the rub. How far would a billion dollars get us with this technology? Not that there is anything wrong with researching it.

[Bread and Circus]

10. Not sure... but yah...that's the rub. But almost all energy systems other than bicycles are pricey..

:)

[zipplewrath]

15. This comes up every few years

On some level it sounds useable. The real issue is how many cars are you planning on supplying simultaneously. That can be a tremendous amount of current. And depending upon how you plan on configuring the system (there are many ways) you'll be fighting large losses due to the inverse square law.

The system is often presented for "in city" use where the scale of the system can be controlled and compact. However, in city is where you need this the least because trips are short and stationary recharge systems can be utilized. (Actually induction systems in garages are often proposed for home and parking garage installation). It is the longer trips where it is seen as being able to supplement the normal battery based power. But again, now you're talking about alot of power, and alot of extended infrastructure.

Now it has been proposed on occasion to replace overhead wire systems in cities for buses. Part of the reason is because it is thought that other public vehicles might be able to utilize it. (city cars, school buses, police cars, etc). Again, as long as one can control the peak demand, it might find a use, although it would be very cost intensive up front.

It's not that it can't work anywhere, it is physically possible. The question is really weather it is a reasonable approach in most places. The infrastructure hit, and associated cost, is often prohibitive.

[MineralMan]

5. Tough nut, that concept.

First, the amount of power that would have to be imbedded in the roads would be very expensive to provide, and insulating it against losses would be even more expensive.

Second, the inverse square law means that inductive pickups on the vehicles would have to be almost in contact with the array to draw enough power to be useful. Air gaps do poorly in induction systems.

Third, if you add up all the costs of providing such a system, it would be prohibitively expensive. Additional batteries with a charge-at-home capability would be far cheaper. The infrastructure just doesn't make economic sense.

[Greyskye]

17. Answer to your 2nd point:

You're absolutely correct, so let's think outside the box.

Design the inductive pickups into the wheels/tires. Sure, you'll need a complete redesign of the tires and wheels, but nothing's ever easy, eh? :D Now we just need answers to the other points that you brought up. :rofl:

[yowzayowzayowza]

18. ...or a deployable 5th wheel designed specifically for power harvest...

w/o other requirements of standard tires.

[MyUserNameIsBroken]

7. Two problems I see right away:

1) Scalability. The system might work in a small country like SK. The US, though, has orders of magnitude more roadway to deal with, and longer stretches of rural highway.

2) EMF generation. If the inductors are providing enough current to power many vehicles at highway speed, what sort of electromagnetic field must they put out? I'm not sure I want my butt sitting on top of one of those for hours on end, or during rush hour on a regular basis.

[Bread and Circus]

12. EMF...there's wires everywhere you go already conducting electricity...

every city, town, road, and farm.

I'm not sure how much different it would be if the electricity was embedded rather than overhead.

[XemaSab]

16. I'm less worried about my butt than I am about other areas of the body

:scared:

[Turbineguy]

8. I can't remember for sure

but depending on the distance between the the two parts, loss increases. So the road would have to be flat and smooth and the vehicle close to the ground. But it seems like a really good idea, reducing battery weight and all.

[phantom power]

9. Seems to me that the maintenance cost would be prohibitive.

[Bread and Circus]

11. Sounds like a solid state system to me... you have wires over your head

everywhere you go...why not in the ground?

[phantom power]

14. I'm thinking about what I see done to roads...

where it seems every few years they take them right down to the gravel, and rebuild them. Now, imagine if you had to do that with a bunch of electrical infrastructure embedded in there too. That sounds pricey, either in terms of damage to the system, or in terms of avoiding damage to the system.

[Dead_Parrot]

19. Depends how deep you could put them

If you could get the coils a couple of feet down, they wouldn't need digging up everytime the road is resurfaced... so long as they don't need replacing too often, it could work.

[OKIsItJustMe]

24. Inverse square law?

http://en.wikipedia.org/wiki/Inverse-square_law
http://en.wikipedia.org/wiki/Wireless_energy_transfer#Induction

Induction devices are already commonly buried in roadways, but not very deeply.
http://www.howstuffworks.com/question234.htm

[Dead_Parrot]

25. Doesn't always apply...

Look at lasers, or that space solar beaming set-up: If you can direct the energy, the ISL takes a running jump. The witricity demo managed to run a 65W bulb from 2m, at 45% efficiency, which isn't too bad compared to internal combustion's 25%.

No idea if their set-up would work on a moving target, though, because it's (wait for it) not my field.

Boom tiss. Thank you, I'll be here all week.

[madrchsod]

13. in illinois we can just keep the roads from falling apart each year

putting charging system in the roads would be economically impossible. that`s not taking into account the amount of ice/snow pack on the roads and the use of salt.

it could work in the southern regions of the country.

[excess_3]

20. tax-per-mile is a political dead end

get used to it

[Dead_Parrot]

21. Certainly not dismissing out of hand...

For one thing, it seems you can buy it for trains and trams now, so it's not the usual "in a few years" tech solution. The issues that spring to mind are are:
a) As PP said, keeping the road-side gear out of the way of routine maintainance;
b) cost; and
c) what are the losses and embedded energy costs of setting up the thing? The latter are offset by lighter vehicles and less battery embedded costs, but I'd be interested in seeing some figures.

It's certainly intriguing, especially for cities and motorways (freeways, autobahns, whatever you like to call them :) )

[Optical.Catalyst]

22. A pilot project for this would be well in order

Any magnetic field strong enough to transfer power from a coil buried in the roadway into a vehicle above it is strong enough to have noticeable effects on other things in the road. Attraction of metal trash and debris would be the first thing that comes to mind.

Strong magnetic fields effect can have unintended consequences too. Most modern automobile engines use a technology call the Hall Effect to determine the position of the engine's crank shaft and cam shaft. If the induction coils produce a magnetic field strong enough to interfere with an engine's electronic ignition system, chaos would ensue.

Even for older cars, the magnetic field might erase the 8-track tapes in the storage case in the back seat.

[happyslug]

23. Sounds like the old DC Trolley system, the electric line was BELOW ground level

The electric cable was below ground level do to the fact that DC law forbade overhead wires. It should be noted that the DC system, once out of DC, reverted to overhead wires. The reason for the switch was it was much cheaper to make the overhead wires safe i.e. not to kill anyone walking on the road, then the underground system mandated by DC.

Picture of remains of the old underground system in DC:

http://www.clouse.org/dctrans.html

At Pennsylvania Avenue and 4th Avenue on its own Right of Way showing the underground system in use:

http://world.nycsubway.org/us/washdc/dctrolley.html

http://www.shorpy.com/node/4325