Okay, maybe I'm a bit short in my critique because I'm generally annoyed with the initial premise here, that's hiding in the background that no one is talking about which is:
Why are we thinking of this in the first place?
Why are we talking about the idea of electric vehicles to begin with? The ICE has been a steady workhorse for man for about a century in various forms. It does the job, cheapy effectively, and by most people's account, efficiently.
So what's all this about? Getting away from fossil fuel? Why? Well, someone thinks that the ICE is bad for the environment and causes global warming/cooling/change/weather... whatever the name of the day is.
The whole premise of this exercise is to do something that when looked at through the lenses of overall efficiency, cost effectiveness, reliability, and total environmental damage makes absolutely no sense what.so.ever.
It is never a bad thing to consider alternatives, or revisit ideas as new technology becomes available. But there does come a point where pouring good money after bad, to sway public opinion, support faltering businesses that can't compete with the legacy technology, is just a really dumb idea.
And to those who are complaining about those of us who are 'quick to tear apart' ideas vs. build them up, I'd submit to you that we just come to the conclusion above faster than you did, and are ashamed that more professionals aren't as astute. (Truth be told however, it would appear that reality is winning out over fantasy in the end.)
I had an earlier post regarding how to bill users -
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.
... remember Heinlein's "The Roads Must Roll" or Asimov's "Caves of Steel"? Active mass-transit roadbeds, whether megascale conveyor belts, or electrically wired, wireless, microwave, maglev, bla bla bla, will always be horrendously expensive and prone to breakdown and (these days) fundamentalist or greenie terrorist sabotage. High-density internal energy storage and freely-driven vehicles are the high standard that's been set; anything centralized will be a step down into tyranny.
Unlike 99.9% of the readers here, I actually did some R&D work in the late '80s with resonant power couplers for commercial aircraft applications. Inefficient and unreliable for starters. At 10kW power densities, even with 25-year more mature power devices & embedded control, you're talking a huge waste in power and probably MTBF of months, not decades.
IMO it's time to cast away altogether the bright idea of mass transit except in very dense urban zones.
The first question that I see is about the efficiency of the energy transfer. That will be the very most limiting portion of the system as far as the technical challenges go. The second challenge will be much bigger, which is figuring out how to pay for a roadway that can transfer power to the vehicles. That sort of infrastructure is not cheap, it would cost a whole lot more than good concrete roadways, which appear to be beyond the scope of possibility in this part of Michigan.
Of course, the efficiency can be a whole lot better if power is only transmitted when there is a vehicle to recover it. That sort of control system can certainly be built, but it will not be cheap either. So now we have two parts of the system that each are quite expensive, and what has not yet been mentioned is how the accounting for the energy delivered will be billed to the user. So while the concept is indeed quite exciting, it certainly looks like one of those non-affordable projects, not because we can't design it, but because we can't afford to pay for it.
One other serious concern is about where all of this power would come from. The problem would be the worst when a whole lot of folks were driving on the same road at the same time. The logistics of bringing a whole lot of power to the roadway at certain times is another area that be expensive.
Of course some will say that it is easy to shoot down an idea, and they point to the cell phone explosion of 15 years ago. The differences are that cell phone infrastructure is a lot cheaper, and more importantly, the cell phone infrastructure could grow from the revenues as time went by. And there was no competing technology to provide a cheaper alternative. Inductive power transmission does not have that advantage, present cars and gas stations are very effective at providing comfortable transportation. So that is a big difference.
We can say that "it is a good idea, except for a few problems."
Mark S Happy to see you read some Tesla! Truly a man before his time yet this genious was blocked by the likes of J.P. Morgan and other Wall St. types. Please rememberHE DID HAVE an ELECTRIC POWERED Pierce Arrow THAT DID NOT USE BATTERIES FOR IT'S ENERGY SOURCE.As the EV thinking moves closer to engineering laws of physics and quantum physics the old masters predictions WILL be proven correct.
Something else that is interesting and discusting to me are the comments from some "engineers" made on these pages which, are disturbing to me in that they are destructive and detramental rather than objectively critical and creative. To me, and I believe other engineering professionals, this does NOT present to the public a true picture of our profession, and I hope to see gone from DN etc. ASAP.
Thanks for catching me on exactly what I was criticizing others for. We pay the price every day for our use of mixed measurement systems. Ouch. Mea culpa. The result looks much more reasonable at 20 kwH.
In the old days, I would have put this down on paper with the units and checked the unit conversions and found my error. Even though I put the units to the side of the cell entries in Excel for this exercise, the entries weren't in a form that forced me to do a complete units check.
Amen to the Practical engineer- I give you 5 stars.My favorite line: "every engineer in the room wants to show how smart he is by DEFEATING an idea " –-- you have an outsiders view of design engineers in general. We are all guilty in that manner, and we all routinely say, "It'll never work".Accordingly, there are 4 pages of comments here which are (mostly) accurate and real roadblocks to this idea, and I applaud them all; because largely, this IS a silly idea .... But ONE thought kept coming back to me again and again:In 1975 there was a proposed technology that had a very similar audience.It required the PREPOSTEROUS idea of building out a nationwide cellular infrastructure!(Ludicrous-! ! )37 years later there are so many networks, several do not even cross-link [i.e., cdma/gsm].
I bet the current presidential administration would love this idea, because it would get votes from folks who don't understand the issues.
I agree with BobGroh and others - this is a half baked idea that is easily proven impractical in 5 minutes of honest thinking. This scheme works OK for trains and trolleys and monorails at Disneyland - but not for an entire transportation system.
I think we (in the technical community) need to all take a deep breath and ask the deeper question: "what problem are we really trying to solve?" and "what's the best way to get there?".
Electric cars, with batteries or even with "slot-car drive" do not solve our energy problem. They do not use less energy overall (about the same) and only serve to transfer the energy source from Oil to Coal + Natural Gas + misc. Until the "misc" power sources of the grid are a majority renewable, EV's do not help much at all. They are just a big distraction and wasted cost. Let's focus our efforts to convert the grid to renewables, which will require adding energy storage on the grid, and let the automotive sector get off of fossil fuels more directly.
Here's a much more practical near-term solution: Coal-to-Gasoline http://www.ultracleanfuels.com/ China, India, and other countries have already discovered this...but the USA is still pouring government money down the proverbial rathole of EV's. Cut out the "middle man" (of power plants burning coal) and just make gas from coal!
Longer-term solution is Biofuels or Solar Synthesized fuels, to get us off of all fossil fuels.
Note that either of these requires ZERO (or minimal) change to existing infastructure, and still accomplishes getting us off of oil (near term) and fossil fuels in general (longer term).
Practical Engineer, I understand where you are coming from, but it is a major part of the role of an engineer to determine feasibility of an idea.
In this case, the title promises the replacement of EV batteries.This is only practical if you electrify every mile of road in the country.The cost and time involved mitigate against that.There have been many proposed alternatives to the ICE, but none of them are gaining a lot of traction.Counting all the hybrids and electric vehicles that have been sold (Prius, Volt, Leaf, Tesla) you have a very small percentage of the vehicles on the road using electric technology of some sort.And most of them are going to be hybrids that still use an ICE.So, the impact is negligible.
Now, if you relax one of the goals, that of replacing batteries, you might have something workable.Assume that vehicles have batteries.Electrify the long distance roads and let the vehicles charge from the roadway and you might have something.Of course, you still have a battery.Another alternative is to have an ICE for short haul situations, or situations where the electrified roadway is not available yet.This might start to be useful.
As of now, there are no technologies that are practical for powering personal vehicles other that the ICE (I include hybrids which use and ICE).Any replacement would have to provide the same utility at a similar price to be voluntarily adopted.Personally, when I can I use public transport.
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