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Science Forum

  1. 12 Aug '16 18:47
    The Karma Revero has solar panels on the roof. Is this the first production car to feature solar?
    https://www.youtube.com/watch?v=g3H3rJ3jDqQ

    Just how much extra range would one expect from solar on the roof?
  2. Standard member sonhouse
    Fast and Curious
    13 Aug '16 06:34 / 1 edit
    Originally posted by twhitehead
    The Karma Revero has solar panels on the roof. Is this the first production car to feature solar?
    https://www.youtube.com/watch?v=g3H3rJ3jDqQ

    Just how much extra range would one expect from solar on the roof?
    Did you miss the part where they said the cells give 200 watts? Not much energy.
    If left in full sun for 8 hours, that would only be 1.6 Kwhr. I think Tesla's have batteries of around 25 Kwhr rating so using those numbers, it sounds like it would get maybe 5 % increase in miles and that only after charging in full sun all day long.

    200 watts would MAYBE get the thing going 2 km/hr if that was the only source of energy
  3. 13 Aug '16 07:10
    So, it just for show. I wasn't sure. Previous discussions on the topic had suggested that it would make more sense to spend more money on extra battery and to install solar panels at parking bays. This particular car is a hybrid anyway so it could just have a slightly larger fuel tank to increase range.
  4. Standard member sonhouse
    Fast and Curious
    13 Aug '16 15:50
    Originally posted by twhitehead
    So, it just for show. I wasn't sure. Previous discussions on the topic had suggested that it would make more sense to spend more money on extra battery and to install solar panels at parking bays. This particular car is a hybrid anyway so it could just have a slightly larger fuel tank to increase range.
    Show for now anyway. Never can tell when cell efficiency will make a big bump up.

    For one thing, there is not much surface covered with cells, suppose someone engineers 30% cells but not separate cells like that but the paint itself converts 30%, covering the whole car.

    Then it would not be 200 watts but 2000 and in an 8 hour day of sunlight it would charge up 15 odd Kwhr, a significant sea change when that comes about.

    I am not holding my breath however
  5. 13 Aug '16 16:46
    Originally posted by sonhouse
    Then it would not be 200 watts but 2000
    Where do you get the 10 times improvement? You might at best get double the area in sunlight.
  6. Standard member sonhouse
    Fast and Curious
    15 Aug '16 02:59
    Originally posted by twhitehead
    Where do you get the 10 times improvement? You might at best get double the area in sunlight.
    You still get energy in the shaded portions but not as much. Anyway it is a long road to get to that point anyway. Thing is, efficiency goes up, price goes down, cars get more streamlined, who knows what electrics will be like say in 2030 or so.
  7. 15 Aug '16 07:15
    Although solar on cars is an interesting concept, far more important right now is the price of batteries which Tesla will bring down through mass production techniques.
    Also of interest will be the major disruption that electric cars and autonomous driving will bring to the car business. Electric cars require less maintenance and autonomous driving should mean fewer accidents as well as open up car sharing possibilities. Overall, a lot less cars will need to be manufactured and the parts business will drop significantly. Add to this all drivers being out of a job.
  8. Standard member sonhouse
    Fast and Curious
    15 Aug '16 13:27
    Originally posted by twhitehead
    Although solar on cars is an interesting concept, far more important right now is the price of batteries which Tesla will bring down through mass production techniques.
    Also of interest will be the major disruption that electric cars and autonomous driving will bring to the car business. Electric cars require less maintenance and autonomous driving shoul ...[text shortened]... ured and the parts business will drop significantly. Add to this all drivers being out of a job.
    Well don't hold your breath on the elimination of drivers. There may be a sea change in the parts business, for sure less combustion engine parts but there are still tires, steering, struts, shock absorbers, none of those go away as the result of an electric engine.

    The best use of electrics is one wheel, one motor, the motor built into the wheel assembly, and one for each wheel, four per vehicle. The whole design of the auto will be up for grabs if that happens.

    Still gonna need all that steering stuff and windsheild wipers and heaters and air conditioning and radio's and amps and speakers and players of whatever tech is popular at that point in the future where electrics overtake combustion.
  9. 15 Aug '16 14:04
    Originally posted by sonhouse
    Well don't hold your breath on the elimination of drivers.
    Why not? Full automatic driving for regular routes is a mere five years away.

    There may be a sea change in the parts business, for sure less combustion engine parts but there are still tires, steering, struts, shock absorbers, none of those go away as the result of an electric engine.
    But they are significantly less parts needing replacing overall.

    The best use of electrics is one wheel, one motor, the motor built into the wheel assembly, and one for each wheel, four per vehicle. The whole design of the auto will be up for grabs if that happens.
    I don't see why. The motor is hardly the one key component of a vehicle.
  10. Standard member sonhouse
    Fast and Curious
    15 Aug '16 14:31
    Originally posted by twhitehead
    Why not? Full automatic driving for regular routes is a mere five years away.

    [b]There may be a sea change in the parts business, for sure less combustion engine parts but there are still tires, steering, struts, shock absorbers, none of those go away as the result of an electric engine.

    But they are significantly less parts needing replacing over ...[text shortened]... s if that happens.[/b]
    I don't see why. The motor is hardly the one key component of a vehicle.[/b]
    If the motors are in the wheels that allows individual control of traction and sensors can tell when available friction has been exceeded and wheel spin happening, so feedback circuitry can maximize available traction. Like today's traction control but a lot faster in operating times. It makes for a much simpler traction control compared to the clumsy and complex mechanical assemblies of today, all wheel drive, dual front V rear and all that.
  11. 15 Aug '16 15:32
    Originally posted by sonhouse
    If the motors are in the wheels that allows individual control of traction and sensors can tell when available friction has been exceeded and wheel spin happening, so feedback circuitry can maximize available traction. Like today's traction control but a lot faster in operating times. It makes for a much simpler traction control compared to the clumsy and complex mechanical assemblies of today, all wheel drive, dual front V rear and all that.
    It wouldn't change the sensors at all, only the speed of response. But what does that have to do with anything? Slightly better traction control. So what?
  12. Standard member sonhouse
    Fast and Curious
    15 Aug '16 16:31
    Originally posted by twhitehead
    It wouldn't change the sensors at all, only the speed of response. But what does that have to do with anything? Slightly better traction control. So what?
    Well we live in a very wet state and traction control is a key feature I look for. Tires have tread ratings in terms of traction and the better the traction, usually the shorter the lifespan.

    Anything that helps traction I am interested in.

    I saw a report of a small voltage applied to the tires cotrols traction to some degree.

    A small voltage, like a few volts changes the friction/traction. I would like to have seen that idea developed but saw nothing outside of the original report.