Someone had better figure out the efficiency of the energy transfer between the road coil and the coil in the car. That is a big air gap. This is nothing more then a transformer with one coil in the road and one in the car. The air gap is huge unless you want to reduce the vehicle ground clearance. Transformers are very inefficient with large air gaps. The next technical issue to consider is what operating frequency will this be? We will to be transmitting at that frequency and interfering with everything in the area.
Now let's look at the car. A car made mostly of steel and we drive it over a magnetic field in the road. The magnetic field will attract the steel pulling the car down making it appear much heavier to the tires. That adds friction slowing the car down. Oh and don't forget the magnetic field will be pulling the car towards it as the car approaches. Then pulling the car back as the car trys to move away form the coil in the road. Could make for a jerky ride. We better do more homework before applying to the government to fund this research. Where are the professors at Stanford that should be getting these questions answered? We need a reality check with basic physics here.
Let's just wire the roads in sections, say 5 miles of the HOV lane. Use that juice to power the vehicle or recharge onboard batteries. Have "toll booths" every so often where drivers can swipe their cards to pay for amount of charge used. You wouldn't have to tear up thousands of miles of road, just cut a groove & lay the "wire". No this won't be for everybody but it makes the switch to electrics much more attractive.
The problem with hot swaps is there is no battery pack standard & nobody seems to address that.
@Beth,I agree with you completely. It's a nice thought but it will never happen. The main reason? Money. This paragraph caught my eye:
"To make it all happen, every "powered roadway" would need a very heavy cable running alongside it to carry huge the amounts of current needed for long stretches of roadway. "
Number one: Heavy cabling? You realize that we are on the downward slope of most of the natural resources on this planet. Copper used to be real easy to mine. Dig a hole, follow the seam. The low-hanging fruit is gone now. Copper prices have skyrocketed in the last 10 years.
Number two: Huge amounts of current. Here we are, back to electricity generation again. Just exactly how much electricity does it take to move a car down the road one mile with this system?
Cute idea, but we should really be investing in conventional rail, not high-speed. Just get trains running from one city to another on-time.
This has been floated round since Tesla's day, and except for niche applications (induction heating) it doesn't pass the back of the envelope calculation test. We'll see all-electric railroads here sooner.
Any genius can come up with solutions to problems as long as they don't have to pay for them. How many of us have thought "what if" -- and then realized the biggest obstacle is not the technology but the money. Even the Stanford brains admit they can't figure out how to fund this obviously wallet-emptying idea. Meh. [Edited: Speaking of brains, even I got it wrong. I originally had said MIT when it is Stanford. Must be catching.]
This is a neat idea, but it's not going to be practical for years. It suffers from the chicken and egg problem. Do you build cars that can use it first or do you build the infrastructure first. (note the E85 cars we have now - most of them can't get E85)
Since we are contemplating changing the infrastructure, why don't we look at what we could do now? By making parking lot spaces "pull throug" we wouldn't be wasting gas backing cars up. By making all the traffic lights "smart" lights (which could be done with cameras) you would eliminate millions of wasted gallons of fuel caused by cars idling at uneccesary stops as well as the gas needed to bring them back up to speed after that stop. And these changes would act on every car in the system now - not just special electric cars.
These are changes that our government could cram down our throat that would actually help everyone.
Similar to the EV arguments regarding range - how practical is it to have a car that can only use a limited set of roadways?Not too many consumers can afford to buy a car for limited use.Granted, a hybrid version of this could allow for operation away from the electrified roads and still reap the weight benefits.
I would also like to see the power requirements to keep a highway running at speed.I haven't put pencil to paper, but I would suspect that as the number of coiled cars on the highway grows, the less energy will be available, and everything will slow to a crawl.With adequate power this might not be a problem since the speed of traffic is usually inversely proportional to the number of cars on the road anyway.
I almost want to say that fleet vehicles that run set routes would be a good place to start.If the cost was right, this would alleviate the fuel logistics costs of a fleet.But to keep costs affordable it may require widespread adoption to repay the capital of building the roadways.
What about the efficiency of the system? With the push towards higher efficiencies in vehicles, will technology be competitive and meet regulatory efficiency requirements? I suspect that overcoming the energy losses in the system will be a major challenge regardless of the economics of other aspects of the system.
You could have the car's electric coil metered to measure the amount of charge gathered from the roadway. The cars could then transmit the data to a billing center.
The roadway providers would have to find a way to split that up equitably. GPS could also be used to determine which roadways the car used and for how long if different utilities provided for different sections.
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