A recent patent for a roadway powered electric vehicle via inductive coupling:
@tsm,in order to understand the effect of a magnetic field on a conducting body in the elementary level, you need to use the Lorentz law, which is F=q(E+v x B). Except for q, all others are vector quantities. And you have to analyze the entire loop off circuit to understand how the forces act.
Based on my relatively limited knowledge of electromagnetism, you can charge without creating drag because the field its varying back and fourth. While it can be creating drag in one quarter of the cycle, it can create propulsion in the next quarter cycle. And this occurs in thousands of times per second.
@George, I think inductive charging is a great idea for electric cars on long trips. Drivers would carry an onboard power meter and be billed by the power company of their choice each month. They can decide when to charge their batteries while on the fly so that they can commute around without charging on the road.
Good posts guys, and a great link insightful. Clearly this is an area that I need to study up on. It may not ultimately turn out being feasible, but not for the reasons I thought.
Time will tell. Meanwhile, I’m learning something. It’s a good thread.
From Wikipedia:
“The drift velocity deals with the average velocity that a particle, such as an electron, gets due to an electric field. In general, an electron will ‘rattle around’ randomly in a conductor at the Fermi velocity. Free electrons in a conductor vibrate randomly, but without the presence of an electric field there is no net velocity. When a DC voltage is applied the electrons will increase in speed proportional to the strength of the electric field. These speeds are on the order of millimeters per hour. AC voltages cause no net movement; the electrons oscillate back and forth in response to the alternating electric field.”
Amazing, huh?
Yup.
What they’re describing is simple electron flow.
The parts that’s not well understood is magnetic fields. We have great knowledge of their behaviors, but don’t really understand the fields themselves. We also don’t really understand the relationship between electrons and magnetism. Again, we’ve learned what the behaviors are, but don’t really understand why.
The behaviors get even stranger. If you bring materials with sufficient free electrons to near absolute zero, that point where subatomic activity ceases, the atoms begin to behave as a wave rather than as individual atoms, and electrons “skate” across the atoms unimpeded. That’s the principle of the “superconductor”. The reasons are not yet well understood.
Wow. Just wow.
(Note, from the article, that they have already tried (and largely failed) to bilk the US Gov’t for funding, and are now crowd sourcing.)
Well, we can build roads. We can build solar arrays, too, and put them adjacent to existing roads. We could even link the two, somehow, for travel purposes.
But to build the road OUT OF solar panels? Of the many, many, downsides, let me say:
- Unproven tech
- Probably more expensive than building both seperately
- Like the “flying car” story here, getting ONE machine to serve TWO disparate jobs generally results in it doing a lousy job of both.
- Making a road out of it means you cannot incline the panels to catch the sun directly (solar panels are inclined at a degree equal to the latitude of the location).
- Making a road out of it means the copious quantities of dust will decrease efficiency, as will oil/rubber/miscellanious schmutz.
I mean, I could see if each and every rooftop was covered in solar panels, then you’ve reached saturation point and need to start looking elsewhere…but why not do the cheap and easy fixes first? After all, there is the notion of “opportunity cost”: there is a finite amount of $$$ out there available for solar power, and a dollar spent here is a dollar less to be spent elsewhere, where the returns (MW per $) are 99.99999% likely to be better; thus, funding this at the expense of more profitable opportunities would result in a net DECREASE in green power!