... No one in the US would consider funding this expensive monstrosity. Arthur
You just don't get it do you Arthur. Wishers and dreamers don't worry about cost or technical feasibility.
The inductive recharge road way is probably technically feasible but does have many technical problems to over come. I however include efficiency as a technical consideration. Probably at least 9 units of energy would be converted into heat for every unit of energy put into the battery.
Part of this large loss fraction is due to the fact the roadway coils are large and have large currents in them with large RI^2 losses. They are relative low voltage high current devices as it is ONLY* the current that makes the inductive field. That means that every 100 meters or so along the roadway there is a high voltage to low voltage transformer. You can only efficiently transmit electrical energy long distance at high voltage. Typical power line is at at least 50,000 volts so the step down ratio would be greater than 1000 and be associated with considerable loss, just in the transformers.
The cost of hundreds of millions (one every 100 meters along the road) of large high-step-down high peak power capable transformers would be more than the cost of the cars using them. The cars on the hi-way are traveling at about 100 feet per second which means you have only about 0.01 seconds to transfer energy form the road way coil to the car coil, yet the car requires considerable energy (as is supplied by gasoline in the IC car). Thus each coil and the road side transformers are a very high power system that delivers energy less than 1% of the time - I.e. power level capacity, which is what determines the cost of the transformers and coils is more than 1000 times the average power level as they are rarely in use - very low duty cycle, even when the traffic is heavy the duty cycle would not exceed 0.01! This is just backwards for what is economically feasible in electrical generation system. I.e. they use low capital cost gas turbines, to serve their low duty cycle peak demands. Never can you afford high capital cost equipment that just sits unused 99.9% of the time. At night it might be minutes between coil turn on, for recharge duration of 0.01 seconds as the car passes rapidly over the roadway coil.
Unfortunately, these large inductance coils can not come up to full current in the tiny fraction of a second they will be used. At least 0.1 second will be require for their currents to build to desired full strength. Likewise you can not just switch the current off instantly -Doing that, even if the switch could not be destroyed by the high voltage inductive arc, would send many kiloVolt voltage spike back to the low voltage side of the roadway transformer and destroy it as well as a lightning strike could. (Lightning protection of all the road side transformers is another practical and cost problem I will not discuss.)
Thus the coil will be energized at least 10 times longer than it is in use - this alone will kill the efficiency of the system, but probably not be as great an energy loss as in the transformers which are energized 100% of the time even if only supplying current for coils pulsed on for only 0.1 seconds.
Also It should at least be mentioned that the metal bottom of the car is over the energized road way coil longer than the car's energy pick-up coil is and eddy currents are induce in that metal I.e. more energy will just heat the car bottom than will enter the battery
When these losses (and others not discussed) are added up, less than 5% of the system energy ends up in the battery. That could be greatly improved by having the car pull off the road every 10 miles or so and sit for five or more minutes to statically recharge.** - Perhaps system efficiency could then approach 50% but I assume dropping the car's averge speed to <15 mph on the hi-way is not acceptable so will assume the system efficiency is 0.05 and that half of the system energy comes from a fossil fuel. That mean this road way coil recharge systrem will boost CO2 release ten fold compared to fossil fuel IC cars.
Like the battery swap recharge system suggested by wishers and dreamers, who re not capable of any analysis, this roadway recharge coils system may have very limited applications. For example as "people movers" in Zoos or Disney Land type of park where instead of short cars rapidly passing over the roadway coils a long train like vehicle is moving at less than 5mph for the people on board to see the animals etc. But as a general hi-way system for short, rapidly moving, cars, it is DoA, at least by a factor or 25. I.e. even if the cost could be reduced 25 fold and the energy efficiency increased by 10 fold, the system would still be DoA.
*NOTE: Electric trains are feasible as they are NOT collecting their energy inductively. The trains use high voltages to move along the track, no need for high currents to get their power as in the inductive roadway coils. Even still they have power transformers (with about 10 to 1 voltage step down) every few miles to energize the over head high voltage lines. I.e. the energy travels from the power plant to these transformers at ~10 times higher voltage still (for 100 times less RI^2 losses in energy distribution) than the high voltage in the over head lines the train is using.
** During peak traffic times, this "improved efficiency" side-of-the-road recharge coil system has the same "wait in line" problem that the battery swap system does. I.e. there typically will be 10 or more cars waiting in line for their turn to recharge, so your recharge delay is nearly an hour and your average speed down the highway drops far below what you could achieve if on a bi-cycle.
