SSC "Going Green" Supercar

no7fish · July 30, 2008, 10:09am

OK, if you want to call them a source that’s fine but we’ve already discussed the obvious fact that they are not the only source of energy if they can go years without recharging.

You’re conflicting your own statements here. No batteries? Who said that? (I menat that they may be used for storing the energy that they are generating by some other means, ie. solar, whoknowswhat, etc) And they said themselves it could go long periods without recharge so how is that flawed?

I don’t see why it offends you that we can sit and theorize about what they MIGHT be using and what they COULD mean by various statements in their press release. You’re obviously a clever guy but you seem very committed to the idea that any discussion is pointless… well then why are you wasting your time?

frodus · July 30, 2008, 11:42am

OK, if you want to call them a source that’s fine but we’ve already discussed the obvious fact that they are not the only source of energy if they can go years without recharging.

You’re conflicting your own statements here. No batteries? Who said that? (I menat that they may be used for storing the energy that they are generating by some other means, ie. solar, whoknowswhat, etc) And they said themselves it could go long periods without recharge so how is that flawed?

Good, Me and the rest of the engineers/scientists/teachers out there will happily call them a power source.

I have not conflicted my statements, I’m going by what you said, and the article. You’re the one that alluded to one power source, maybe you should be more specific:

“” will feature a revolutionary power source"

That kinda means they’re planning to generate power in some way. Whether that is solar, fuel cell, magic, Ionnowhat, Unobtanium, etc, who the F knows. "

To me that sounds like the “power source” you are talking about is by solar, fuel cell, magic…etc. You never mentioned batteries as a storage device. How was that “obvious” that there are batteries AND another power source? Batteries or no batteries, the sheer energy required from this power source is astounding.

Its only a flawed interpretation because we don’t know if they’re driving at all in that 6 years, or if its just sitting there HOLDING a charge. There’s a huge difference. You’re assuming they mean to drive it continuously for 6 years without a charge due to some sort of alternate means of generation.

I don’t see why it offends you that we can sit and theorize about what they MIGHT be using and what they COULD mean by various statements in their press release. You’re obviously a clever guy but you seem very committed to the idea that any discussion is pointless… well then why are you wasting your time?

I’m not offended at all, I’m theorizing like you, except I’m thinking it WON’T work, you are arguing that it does. I’m using scientific method and calculating what power is needed. I’m providing an alternate view and you don’t agree. I’m actually having quite a bit of fun playing devils advocate on this one. So far I’ve provided calcs on what power would be required if it was batteries only, and you have only pointed to the article as being the proof. Where’s your scientific method to proving why its going to work? This isn’t rocket science. I don’t care where they get their power, but I do care how MUCH power is required to hold to those specs. Its quite a bit, and after working in Power Generation at GE for 6 years, and as a field engineer for Alcoa (Aluminum smelter that uses 180,000Amps at 1000V) I have a respect and understanding of power.

Hell, I could disprove you just by the gauge requirements of the cable or bussbar and the sheer weight of what would be required just in copper. How are you going to get all that power for a 500HP (or 1000Hp model) to the wheels without taking into acount connecting the batteries (and generation means) to the motor? Its not light. My motorcycle has ~15lbs of cable in it, and its a 2500Wh pack.

If they wanted to produce 500Hp, they’re gonna need lots of batteries and quite a bit of power to produce that. If they discharge the batteries all the way, what would it take to recharge?

500hp is 372,849.936 Watts. So you use 50% of that (not going continuous on 500Hp) and you get 186,424.968W. Say you run that for an hour. Now, thats a pretty large pack, but I’ll humor you and say we’ve got a 200kwh pack. Now losses for charging lets say is 20%, and you need 223.708kWh to charge it. The onboard charging system via whatever means must replenish the pack.

Lets say you get a 40A 240V receptacle and do ~10,000. Lets say your “generator” charges at the same capacity. that would take 22.4 hours to recharge independantly of the receptacle, at 40A and 240V. Thats a ton of power, and a LONG time to replenish the pack from a 500Hp peak motor running for an hour. We know it won’t run continuous, so maybe divide everything by 2 and do 500Hp for 25% of the time. Still, its 11hours to recharge and 111.5kwh.

So, where’s your argument to me as to why this will work… disregard how they get their power, or the possibility that it can provide the power needed. I’ll let you ASSUME that you CAN “store” 200Kw of power, and the weight is under 1500lbs, and that your SOURCE can provide the means neccessary to recharge the car independantly of grid power.

Tell me how you’re going to:
[ul]
[li]Account for the weight of the bussbar/cable needed to connect all the high power connections?
[/li][li]Account for the massive amount of heat that would have to be dissipated for a system that will supply over 300Kw of power to the motor assuming that your loss from the pack to the motor is at max 90& efficient? (30,000Watts is a ton of heat)
[/li][li]account for the extra weight needed in water to cool this thing, or the extra weight in some other source of cooling (liquid nitrogen, etc)?
[/li][li]account for the weight of the drivetrain required to handle the massive torque of a 500Hp motor that will likely have over 1000ftlbs of torque when starting at 0rpm?
[/li][li]get someone that is crazy enough to strap themselves to 200kw of batteries?
[/li][/ul]

no7fish · July 30, 2008, 12:29pm

HAHA, wow. First, you’re not the only engineer on here so don’t think you’re the only one with any experience. Secondly, I haven’t claimed that they’ll store as much energy in the car as you’re talking about, you’re still putting words into my mouth.

Let me spell it out for you. I’m guessing this will be some sort of an EV with a normal size battery pack. The reason it will not need a “recharge” (most people think of this as plugging it in) for X years is because it will generate some sort of power to recharge itself, probably solar cells, or maybe some sort of thermoelectric generator. I don’t know, but I’m guessing a car company isn’t going to advertise a vehicle as being “best in class for sitting around unused for the better part of a decade and still drive” lol

Just because it’s got “a revolutionary power source” onboard doesn’t mean there aren’t any other power sources of common types (batteries) on it as well. And that was also provided by THEM, not ME as you keep saying.

You’re not devil’s advocating the facts here, you’re reading all sorts of stuff into my points and then putting hysterical numbers to it. I’m not even saying it could work, I’m just asking for possible ways that clever people on this forum can think of that it might. I don’t see your efforts as even remotely constructive unless your aim is an attempt to belittle me by proving you’re so much smarter.

Why are you trying to “disprove me” anyway? I haven’t made any claims. I haven’t said that it could work, in fact I think their claims are a bit optimistic.

frodus · July 30, 2008, 1:43pm

HAHA, wow. First, you’re not the only engineer on here so don’t think you’re the only one with any experience.

I never said I was… I was stating my background and experience in power so you could understand where I was coming from when referring to power.

Secondly, I haven’t claimed that they’ll store as much energy in the car as you’re talking about, you’re still putting words into my mouth.

I wasn’t putting anything in your mouth. I was stating, that if they need 500Hp, that the requirement of Kw in a pack is roughly 200-300Kw. I was saying that is roughly the power requirement… I was going by what they stated, not you.

So you say its the combination of batteries and power source… you still need to get that 200kw from somewhere. That was my point, its going to take some serious power. Hysterical numbers? Just how much power would be needed drive 500Hp 25% of the time?

Let me spell it out for you.

You sure get upset easily when I debate with you… I’m debating… and using supporting evidence. I still have not seen one number or theory from you as to how this would work on the power level required.

I’m guessing this will be some sort of an EV with a normal size battery pack. The reason it will not need a “recharge” (most people think of this as plugging it in) for X years is because it will generate some sort of power to recharge itself, probably solar cells, or maybe some sort of thermoelectric generator.

Again, nothing new. I read that before, and explained that I understood this. Reread my post. Its quite clear that I was going along with your batteries/generation scheme as the “power source”.

I don’t know, but I’m guessing a car company isn’t going to advertise a vehicle as being “best in class for sitting around unused for the better part of a decade and still drive” lol

They’re also not going to advertise that they were wrong, and that carrying 2-300kW of power around with a means to generate its own power is likely a mistake, and that they meant 6 years between replacing batteries OR 6 years it’l hold a charge. Why would they carry the extra weight as a generator when there’s already a VERY WELL developed power grid in the united states? Power conversion efficiency from wall to car is higher than just about any other form of power generation out there. Why put something inferior on a car and weight it down?

Just because it’s got “a revolutionary power source” onboard doesn’t mean there aren’t any other power sources of common types (batteries) on it as well. .

Again, did you even read my post? I realized that you stated in your previous post that you were talking about a car with bats AND power generation. Read my article further on.

And that was also provided by THEM, not ME as you keep saying

Where do I keep saying this? Can you please quote me on this? I’m pretty sure I didn’t say in my last post that YOU are saying only batteries. The whole last part of my post is about how its both, and while it may work, its going to be one heavy motha.

You’re not devil’s advocating the facts here, you’re reading all sorts of stuff into my points and then putting hysterical numbers to it.

I’m picking apart your argument, which at this point, is ONLY that Shelby had a press release. There are no other points your argument.

You tell me just how much power would be needed drive 500Hp 25% of the time? Hell, even 10% of the time. Lets see some numbers.

I’m not even saying it could work, I’m just asking for possible ways that clever people on this forum can think of that it might.

Well, I’m sorry, I’m supporting my own argument why it WON’T work. Maybe someone else can disprove me, or tell you why it CAN work, but right now, you’re the only one out there even defending their claims, and still don’t have any supported theories… other than “they said so in their press release”

I don’t see your efforts as even remotely constructive unless your aim is an attempt to belittle me by proving you’re so much smarter.

Where did I belittle you? I’m outlining my argument. I’m asking for you to support your argument, and you fail at supporting anything. Thats what debate is all about. I haven’t called names. I said I was an engineer in the power field, not to be superior, but to outline my experience in the power industry. I’m not just pulling these numbers out of the air. I’m not smarter, I’m just cutting straight to science, and not relying on the “he said she said” of press releases.

Why are you trying to “disprove me” anyway?

Well, because I can’t “prove” that you’re right, so I pick it apart and look at all sides. Thats what I do for a living. I design systems. Its part of how I think. If I didn’t rip things apart and find reasons something won’t work, someone could get hurt. There’s always another point of view. If I had actually thought this might have some merit, I’d have researched it and you would NOT have heard a peep from me.

I haven’t made any claims. I haven’t said that it could work, in fact I think their claims are a bit optimistic.

FINALLY… We agree on that. They’re really optimistic. Its going to be a tall order to get anywhere NEAR that power, and to house it in a car?

I’m seriously thinking it was a mistake, and that there’s only batteries inside that can handle a PEAK of 200kw, but are likely more the size of tesla. There’s no reason to have an onboard charging system if its a sports car. Maybe if it was personal transport, some sort of a electric hybrid of other technologies would be more realistic, but with sports cars, the art of design is strength and lightweight chassis.

The sheer power requirement of the power generation device is huge. Even an ICE generator at 10,000 (would be needed to cruise) is HUGE and heavy. Solar isn’t efficient enough, and the surface area you’d need is large. Wind would slow you down, nuclear wouldn’t be allowed by the feds, magnet motors are a myth and a hamster wheel just doesn’t cut it.

ManToe · August 4, 2008, 6:41am

I could power a small fleet of EV battleships w/the energy excreted in the quoting above…

Not to mention I could power my PC w/my mouse scroll wheel.

Get a life dude. Go see BatMan… let us know if all his gadgets would “really really” work.

[QUOTE=frodus;4308]I never said I was… I was stating my background and experience in power so you could understand where I was coming from when referring to power.