• A couple of problems with EV charging roads?

    From Crash Gordon@21:1/5 to All on Sun Jun 2 12:32:25 2024
    I've seen a couple of articles about roads with embedded inductive
    charging for EVs. And there are a couple of issues that seem to me to
    make these roads unfeasible. (I'm not even going to get into any of the financial side)

    My qualifications: I have a few decades experience in circuit design
    and have had the word "Engineer" in my job title at several different employers, but never went to college. So I have a lot of "wisdom-through-experience" but there are a lot of holes in my basic
    knowledge -- I tend to know a lot about the things I know, but nothing
    at all about other closely related things. So I am quite willing to
    accept that there's stuff going on here I simply don't understand. Feel
    free to educate me. Moving along...


    First: Inductive charging is basically building a transformer where the
    primary is in one device (in this case, the road surface) and the
    secondary is in a different device (here, an EV). Ordinarily when we
    design transformers, we take great care to maximize the coupling between
    the primary and secondary because loose coupling is responsible for much
    of the loss in transferred power.

    But in charging an EV there is necessarily going to be a considerable
    air gap between the primary and the secondary. Although we can optimize
    in other areas to account for this somewhat, it seems to me that there's
    going to be a lot of energy lost here, mostly as heat radiated into the air.

    Second: In order to transfer significant energy, there's going to have
    to be some significant coupling of magnetic fields between the EV and
    the road. Wouldn't this be a source of substantial drag? Effectively
    the car would be driving "uphill" the whole time it's charging.


    My thought is that if we're going to be shoveling huge amounts of
    electricity into a road surface, we could use it more efficiently by
    building a giant linear actuator with the EV as the moving part.


    Opinions?

    --
    I'm part of the vast libertarian conspiracy to take over the world and
    leave everyone alone.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to All on Sun Jun 2 10:51:11 2024
    On Sun, 2 Jun 2024 12:32:25 -0500, Crash Gordon <uucp@crashelex.com>
    wrote:

    I've seen a couple of articles about roads with embedded inductive
    charging for EVs. And there are a couple of issues that seem to me to
    make these roads unfeasible. (I'm not even going to get into any of the >financial side)

    My qualifications: I have a few decades experience in circuit design
    and have had the word "Engineer" in my job title at several different >employers, but never went to college. So I have a lot of >"wisdom-through-experience" but there are a lot of holes in my basic >knowledge -- I tend to know a lot about the things I know, but nothing
    at all about other closely related things. So I am quite willing to
    accept that there's stuff going on here I simply don't understand. Feel
    free to educate me. Moving along...


    First: Inductive charging is basically building a transformer where the >primary is in one device (in this case, the road surface) and the
    secondary is in a different device (here, an EV). Ordinarily when we
    design transformers, we take great care to maximize the coupling between
    the primary and secondary because loose coupling is responsible for much
    of the loss in transferred power.

    But in charging an EV there is necessarily going to be a considerable
    air gap between the primary and the secondary. Although we can optimize
    in other areas to account for this somewhat, it seems to me that there's >going to be a lot of energy lost here, mostly as heat radiated into the air.

    Second: In order to transfer significant energy, there's going to have
    to be some significant coupling of magnetic fields between the EV and
    the road. Wouldn't this be a source of substantial drag? Effectively
    the car would be driving "uphill" the whole time it's charging.


    I'd expect that drag to be small. But if the car drops down a coil, to
    be closer to the roadway, air drag will increase.


    My thought is that if we're going to be shoveling huge amounts of
    electricity into a road surface, we could use it more efficiently by
    building a giant linear actuator with the EV as the moving part.


    Opinions?

    It's a silly idea. The cost would be incredible. And we're eliminating
    power plants and working towards rotating blackouts already. Imagine
    adding a megawatt per mile of road.

    Resonant coils can couple fairly well, even with an air gap. I think
    some electric busses charge that way.

    Efficiency will be low. Some of the transmitted energy will heat the
    soil and rerod and car parts. And melt snow!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill Sloman@21:1/5 to john larkin on Mon Jun 3 17:49:45 2024
    On 3/06/2024 3:51 am, john larkin wrote:
    On Sun, 2 Jun 2024 12:32:25 -0500, Crash Gordon <uucp@crashelex.com>
    wrote:

    I've seen a couple of articles about roads with embedded inductive
    charging for EVs. And there are a couple of issues that seem to me to
    make these roads unfeasible. (I'm not even going to get into any of the
    financial side)

    My qualifications: I have a few decades experience in circuit design
    and have had the word "Engineer" in my job title at several different
    employers, but never went to college. So I have a lot of
    "wisdom-through-experience" but there are a lot of holes in my basic
    knowledge -- I tend to know a lot about the things I know, but nothing
    at all about other closely related things. So I am quite willing to
    accept that there's stuff going on here I simply don't understand. Feel
    free to educate me. Moving along...


    First: Inductive charging is basically building a transformer where the
    primary is in one device (in this case, the road surface) and the
    secondary is in a different device (here, an EV). Ordinarily when we
    design transformers, we take great care to maximize the coupling between
    the primary and secondary because loose coupling is responsible for much
    of the loss in transferred power.

    But in charging an EV there is necessarily going to be a considerable
    air gap between the primary and the secondary. Although we can optimize
    in other areas to account for this somewhat, it seems to me that there's
    going to be a lot of energy lost here, mostly as heat radiated into the air. >>
    Second: In order to transfer significant energy, there's going to have
    to be some significant coupling of magnetic fields between the EV and
    the road. Wouldn't this be a source of substantial drag? Effectively
    the car would be driving "uphill" the whole time it's charging.


    I'd expect that drag to be small. But if the car drops down a coil, to
    be closer to the roadway, air drag will increase.


    My thought is that if we're going to be shoveling huge amounts of
    electricity into a road surface, we could use it more efficiently by
    building a giant linear actuator with the EV as the moving part.


    Opinions?

    It's a silly idea. The cost would be incredible. And we're eliminating
    power plants and working towards rotating blackouts already. Imagine
    adding a megawatt per mile of road.

    Resonant coils can couple fairly well, even with an air gap. I think
    some electric busses charge that way.

    Efficiency will be low. Some of the transmitted energy will heat the
    soil and rerod and car parts. And melt snow!

    John Larkin seems to be just as ignorant as Crash Gordon.

    Varying magnetic fields only transmit energy when they induce current in
    the soil, snow and reinforcing rods (which aren't a feature of most road construction). Car parts might be a problem, but a car isn't designed to
    be a Faraday cage, and probably won't present the sort of current loop
    which could pick up much energy from the charging field.

    Electric buses recharge by parking on top of the coupling loop. We
    haven't had any stories about cars parking or waiting briefly on the
    same spots and getting hot - the charging hardware presumably has a bus
    sensor and turns off when there isn't a bus there to charge.

    In-road chargers will presumably be just as smart.

    --
    Bil Sloman, Sydney

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to john larkin on Tue Jun 4 01:35:13 2024
    On 6/2/2024 1:51 PM, john larkin wrote:
    On Sun, 2 Jun 2024 12:32:25 -0500, Crash Gordon <uucp@crashelex.com>
    wrote:

    I've seen a couple of articles about roads with embedded inductive
    charging for EVs. And there are a couple of issues that seem to me to
    make these roads unfeasible. (I'm not even going to get into any of the
    financial side)

    My qualifications: I have a few decades experience in circuit design
    and have had the word "Engineer" in my job title at several different
    employers, but never went to college. So I have a lot of
    "wisdom-through-experience" but there are a lot of holes in my basic
    knowledge -- I tend to know a lot about the things I know, but nothing
    at all about other closely related things. So I am quite willing to
    accept that there's stuff going on here I simply don't understand. Feel
    free to educate me. Moving along...


    First: Inductive charging is basically building a transformer where the
    primary is in one device (in this case, the road surface) and the
    secondary is in a different device (here, an EV). Ordinarily when we
    design transformers, we take great care to maximize the coupling between
    the primary and secondary because loose coupling is responsible for much
    of the loss in transferred power.

    But in charging an EV there is necessarily going to be a considerable
    air gap between the primary and the secondary. Although we can optimize
    in other areas to account for this somewhat, it seems to me that there's
    going to be a lot of energy lost here, mostly as heat radiated into the air. >>
    Second: In order to transfer significant energy, there's going to have
    to be some significant coupling of magnetic fields between the EV and
    the road. Wouldn't this be a source of substantial drag? Effectively
    the car would be driving "uphill" the whole time it's charging.


    I'd expect that drag to be small. But if the car drops down a coil, to
    be closer to the roadway, air drag will increase.


    My thought is that if we're going to be shoveling huge amounts of
    electricity into a road surface, we could use it more efficiently by
    building a giant linear actuator with the EV as the moving part.


    Opinions?

    It's a silly idea. The cost would be incredible. And we're eliminating
    power plants and working towards rotating blackouts already. Imagine
    adding a megawatt per mile of road.

    Resonant coils can couple fairly well, even with an air gap. I think
    some electric busses charge that way.

    Efficiency will be low. Some of the transmitted energy will heat the
    soil and rerod and car parts. And melt snow!


    It seems like a somewhat unnecessary technology, for the same reason we
    don't have in-transit refueling tankers for cars. There are already EVs
    with close to 400 mile ranges and 800 doesn't seem infeasible with
    near-future technology.

    Lots of expense to try to re-invent what sounds like "the electric
    train." Trains hauled by electric locomotives are hard to beat for cost
    per mile.

    Some African countries seem to be leap-frogging over 20th century infrastructure concepts entirely - work using videoconferencing when
    possible, use WiMax and satellite for internet instead of maintaining
    cable and fiber optic, do last-mile shipping via drone delivery, and
    generate power on-site with micro grids rather than run high tension lines.

    I never understood the right-wing refrain that "everybody wants to come
    here" (the US) when it's pretty clear to me that what the majority of
    people around the world generally prefer to do is stay home where they
    were raised with the people and culture they're familiar with, if at all feasible. Infrastructure is expensive, commuting can be depressing, and
    most people don't like to travel very much in the first place unless
    they're on vacation.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to bitrex on Tue Jun 4 06:41:58 2024
    On Tue, 4 Jun 2024 01:35:13 -0400, bitrex <user@example.net> wrote:

    On 6/2/2024 1:51 PM, john larkin wrote:
    On Sun, 2 Jun 2024 12:32:25 -0500, Crash Gordon <uucp@crashelex.com>
    wrote:

    I've seen a couple of articles about roads with embedded inductive
    charging for EVs. And there are a couple of issues that seem to me to
    make these roads unfeasible. (I'm not even going to get into any of the >>> financial side)

    My qualifications: I have a few decades experience in circuit design
    and have had the word "Engineer" in my job title at several different
    employers, but never went to college. So I have a lot of
    "wisdom-through-experience" but there are a lot of holes in my basic
    knowledge -- I tend to know a lot about the things I know, but nothing
    at all about other closely related things. So I am quite willing to
    accept that there's stuff going on here I simply don't understand. Feel >>> free to educate me. Moving along...


    First: Inductive charging is basically building a transformer where the
    primary is in one device (in this case, the road surface) and the
    secondary is in a different device (here, an EV). Ordinarily when we
    design transformers, we take great care to maximize the coupling between >>> the primary and secondary because loose coupling is responsible for much >>> of the loss in transferred power.

    But in charging an EV there is necessarily going to be a considerable
    air gap between the primary and the secondary. Although we can optimize >>> in other areas to account for this somewhat, it seems to me that there's >>> going to be a lot of energy lost here, mostly as heat radiated into the air.

    Second: In order to transfer significant energy, there's going to have
    to be some significant coupling of magnetic fields between the EV and
    the road. Wouldn't this be a source of substantial drag? Effectively
    the car would be driving "uphill" the whole time it's charging.


    I'd expect that drag to be small. But if the car drops down a coil, to
    be closer to the roadway, air drag will increase.


    My thought is that if we're going to be shoveling huge amounts of
    electricity into a road surface, we could use it more efficiently by
    building a giant linear actuator with the EV as the moving part.


    Opinions?

    It's a silly idea. The cost would be incredible. And we're eliminating
    power plants and working towards rotating blackouts already. Imagine
    adding a megawatt per mile of road.

    Resonant coils can couple fairly well, even with an air gap. I think
    some electric busses charge that way.

    Efficiency will be low. Some of the transmitted energy will heat the
    soil and rerod and car parts. And melt snow!


    It seems like a somewhat unnecessary technology, for the same reason we
    don't have in-transit refueling tankers for cars. There are already EVs
    with close to 400 mile ranges and 800 doesn't seem infeasible with >near-future technology.

    One problem with EVs is finding an available (and working) charging
    slot and waiting for your car to charge. The (impractical) electrified
    roadway would fix that.

    More KWHs means longer charging times. I can gas up my car in less
    time than it takes to squeegee the glass. And I never have to wait for
    an available pump.


    Lots of expense to try to re-invent what sounds like "the electric
    train." Trains hauled by electric locomotives are hard to beat for cost
    per mile.

    Diesel-electrics?



    Some African countries seem to be leap-frogging over 20th century >infrastructure concepts entirely - work using videoconferencing when >possible, use WiMax and satellite for internet instead of maintaining
    cable and fiber optic, do last-mile shipping via drone delivery, and
    generate power on-site with micro grids rather than run high tension lines.

    Maybe that's why they are so healthy and have such low unemployment
    rates and such huge GDPs. Some African citizens even have electricity
    and running water.




    I never understood the right-wing refrain that "everybody wants to come
    here" (the US) when it's pretty clear to me that what the majority of
    people around the world generally prefer to do is stay home where they
    were raised with the people and culture they're familiar with, if at all >feasible. Infrastructure is expensive, commuting can be depressing, and
    most people don't like to travel very much in the first place unless
    they're on vacation.



    Google says

    Immigrants and their U.S.-born children number approximately 90.8
    million people, or 27 percent of the total civilian
    noninstitutionalized U.S. population in 2023. This is an increase of approximately 14.7 million (or 20 percent) from 2010.


    Some large fraction of my employees are foreign-born and seem to like
    it here. You don't seem to like it here.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill Sloman@21:1/5 to john larkin on Wed Jun 5 01:36:08 2024
    On 4/06/2024 11:41 pm, john larkin wrote:
    On Tue, 4 Jun 2024 01:35:13 -0400, bitrex <user@example.net> wrote:

    On 6/2/2024 1:51 PM, john larkin wrote:
    On Sun, 2 Jun 2024 12:32:25 -0500, Crash Gordon <uucp@crashelex.com>
    wrote:

    <snip>

    Some African countries seem to be leap-frogging over 20th century
    infrastructure concepts entirely - work using videoconferencing when
    possible, use WiMax and satellite for internet instead of maintaining
    cable and fiber optic, do last-mile shipping via drone delivery, and
    generate power on-site with micro grids rather than run high tension lines.

    Maybe that's why they are so healthy and have such low unemployment
    rates and such huge GDPs. Some African citizens even have electricity
    and running water.

    Nobody is arguing that that they offer a better environment than the US
    does now. The argument is that they don't have to get to US - or even
    better - European standards of living by going through the same
    intermediate stages as we did.

    I never understood the right-wing refrain that "everybody wants to come
    here" (the US) when it's pretty clear to me that what the majority of
    people around the world generally prefer to do is stay home where they
    were raised with the people and culture they're familiar with, if at all
    feasible. Infrastructure is expensive, commuting can be depressing, and
    most people don't like to travel very much in the first place unless
    they're on vacation.

    Google says

    Immigrants and their U.S.-born children number approximately 90.8
    million people, or 27 percent of the total civilian
    noninstitutionalized U.S. population in 2023. This is an increase of approximately 14.7 million (or 20 percent) from 2010.

    The US does like hiring cheap workers from overseas. They haven't had to
    feed or house them while they were growing up, or educate them.

    Australia exploits immigrants in just the same way, but does better at
    getting them paid them same wages as native-born citizens. Trade unions
    can be good at that.

    Some large fraction of my employees are foreign-born and seem to like
    it here. You don't seem to like it here.

    The US is a better place to live than quite a lot of countries. It now
    doesn't compare well with Australian and the northern European countries
    - it was more attractive when I was younger, but the median standard of
    living has stagnated for the last thirty or forty years. The average
    might have gone up, but so has inequality, so the median hasn't.

    --
    Bill Sloman, Sydney




    --
    This email has been checked for viruses by Norton antivirus software. www.norton.com

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to Bill Sloman on Tue Jun 4 22:46:16 2024
    On 6/4/2024 11:36 AM, Bill Sloman wrote:

    Immigrants and their U.S.-born children number approximately 90.8
    million people, or 27 percent of the total civilian
    noninstitutionalized U.S. population in 2023. This is an increase of
    approximately 14.7 million (or 20 percent) from 2010.

    The US does like hiring cheap workers from overseas. They haven't had to
    feed or house them while they were growing up, or educate them.

    Australia exploits immigrants in just the same way, but does better at getting them paid them same wages as native-born citizens. Trade unions
    can be good at that.

    Some large fraction of my employees are foreign-born and seem to like
    it here. You don't seem to like it here.

    The US is a better place to live than quite a lot of countries. It now doesn't compare well with Australian and the northern European countries
    - it was more attractive when I was younger, but the median standard of living has stagnated for the last thirty or forty years. The average
    might have gone up, but so has inequality, so the median hasn't.


    I've had the somewhat unusual experience of being both upper middle
    class and poor in the US at different points in my life, yeah the US is
    great if you're in the top 20% of incomes. There's almost always someone available in any decent-sized metro area who'll provide best-in-class
    goods and services, for a top-dollar price. As a New Englander that I
    usually have the money to afford it at this point in my life doesn't
    mean that I much enjoy paying it.

    Being in the bottom 50% of incomes is less enticing; you tend to pay a
    pretty high price for mediocre service at best, and at worst you'll occasionally get treated pretty much like a degenerate just for trying
    to get something done (as many people who've flown low-cost US airlines
    or taken Amtrak or a bus can attest.)

    Food is pretty expensive by world standards and there is little succor
    in sight for people who rent their housing, as rental costs ruthlessly increase. Neither political party seems deeply interested in this, they
    finally answer to landlords.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)