SSC's plug-in supercar would need the mother of all plugs

With billions in taxpayer moolah floating around to encourage the development of next-generation plug-in hybrids and electric cars, the public needs to be wary of claims of too-good-to-be-true technologies, magic batteries, cars powered by pollen, dandruff, zoo poo, whatever. At a minimum, we should keep a calculator on hand.

Consider, for example, a claim made by Shelby SuperCars, a Washington-based outfit (not affiliated with famed performance-car designer Carroll Shelby) that announced last week that it would build a revolutionary electric vehicle called the Ultimate Aero EV "that will set a new standard in the electric car industry –- one of 10-minute recharges, super horsepower and ranges up to 200 miles."

Thanks to SSC's "Nanotechnology Lithium-Ion" battery pack (buzzwords, anyone?), the car is "rechargeable in 10 minutes on a standard 110-volt outlet and has a 150-200 miles range on a single charge," according to the company's press release.

That sounds amazing, doesn't it? And more that that, completely freaking impossible.



Consider these fun facts: 110 volts times 20 amps (typical household current) equals 2,200 watts -– that's about the draw of two good hair dryers. In 10 minutes, that equals 0.36 kilowatt-hours. Now let's look at the SSC: It's a super-slick, tube-frame sports car weighing 2,950 pounds. It would also have to be shod with foot-wide high-performance tires to accommodate its purported 208-mph top speed. So add 5% for frictional drag. It has a coefficient of aero drag of 0.348, which is to say, it's not very slippery. It has two 375 kW three-phase AC induction motors for a total output of more than 1,000 horsepower.

Tally it all up and you're talking about a car that would require at least 250 watt-hours per mile, estimates electric car guru Tom Gage, whose company, AC Propulsion, supplies core technology to Tesla, BMW and others in the field. In other words, to go 200 miles on a charge, the car would require a 50-kWh battery pack. In itself, that's plausible; after all, the Tesla pack is 56 kWh. What's wildly, insanely not plausible, and is in fact a monstrous load of fertilizer, is the claim that you could recharge such a battery in 10 minutes on household current. For that you would need to plug into 300 kilowatts, or 0.3 megawatt, roughly the equivalent of a small neighborhood substation.
more:
http://latimesblogs.latimes.com/uptospeed/2009/01/shelby-supercar.html

1,000 horsepower? Look out Koenigsegg!

Charge a bank of stationary capacitors in your garage via 110v. The bank should recharge 50kwh in about 22 hours. When you get home, plug it in (to your "mother of all plugs"... probably a massive set of magnetic contacts in the garage floor).

The capacitors discharge into the onboard battery bank. Could that take place in 10 minutes? If the batteries could accept a 300kwh charge rate... sure.

BTW, Unlike an IC motor, the ac motor horsepower is largely irrelevant to cruising amp draw or range.

I suppose if you were Dr. Frankenstein you could reanimate the dead too.

... and a Jacob's ladder. :thumbsup:

:scared:

Is a stationary 50kw battery bank more or less safe than a mobile one?

Only weight and handling. If your going to drive 200mph you'll be walking soon enough.

wind powered cars now replacing every single gasoline car in America, has already cornered this market, even though they can't seem to deliver these cars.

Reality just isn't up to snuff to meeting imagination.

SSC's press release does not say "rechargeable in 10 minutes on a standard 110-volt outlet" it says "10 minute full battery recharges on a 220V service." Unless they did a quickie edit on their webpage, the journalist changed this to "110 volt outlet."

Now "220V service" implies you are connecting direct to the 220V mains to your house, not using a commodity 220V(RMS) outlet. That is , connecting a charging station with its own outlet by big thick copper wire, since 200A is a huge amount of current. The charging station would likely transform this voltage up so the plug into the vehicle can use less thick copper.

If your house has them, 220V mains are generally rated at 200 Amps(RMS). So that's about 44kW. Ten
minutes would get about 7 kWh of energy depending on system losses, which couldn't be too large or else
you'd have so much system loss that something would have to be overheating someplace in there.

If you assume typical internal combustion engine efficiency, that's about one gallon of gas equivalent,
and from the look of that car aerodynamically and with rolling resistance, taking into account regenerative braking (I have not verified that SSC claims the unit does use regen braking) it probably would get the equivalent of 45 to 50 mpg combined (other cars like it get bad mileage not due to their body or wheels but due to a honking huge race engine.)

So it is correct that SSC's numbers do not make sense, but they are not as far off as the skeptic-who-was-too-lazy-to-be-skeptical-of-the-journalist makes them out to be. They are off by a factor of 4 or 5. Li-FePSO4 nanotech batteries can indeed charge in 10 minutes, just not off normal residential 200V service.

I'll put my bet on the battery pack being in the 30kWh range and being limited to 80% depth of discharge, so a "full charge" of 24kWh, which in 10 minutes would require ~ 150kW.

Not saying I believe SSC will actually even take this thing to market or defending their business in any way, I just hate it when these snotty self-appointed debunkers don't do their homework or use any common sense whatsoever.

We went through all this WRT the still-vaporware EEStor ultracaps. Personally I know nobody who is seriously looking at an electric car who will find it to be a deal-killer that they cannot drive 200 miles to their house, and leave on another 200 mile trip just 10 minutes later. That would be the kind of absurd behavior one would only expect from of I don't know, Vin Diesel or "free credit report dot com guy." Most of us would charge overnight and then drive smugly by the people freezing their fingers off at the convenience store in the morning -- or not, if it isn't on our route.

Native ability to do regen is the primary benefit of AC.

I still think that ultracaps are very promising, and as part of a stationary quick-charge system, feasible.

There would have to be control circuitry to turn off the home's AC, electric water heaters, ovens, stoves, dryers, etc., and that's just the beginning of the headaches.

When I was working construction I'd occasionally see large homes with three phase and/or 400 volt service. The owners of these homes are exactly the sorts who would purchase a car like this, but they are also the sorts who will air condition an entire 10,000 square foot house with two or three occupants 24/7, even when nobody is home, making the energy efficiency or gasoline savings of an electric car entirely moot.

Nevertheless, transfering that much electrical energy in a short time allows very little room for error. If folks like KBR who can't even put together an ordinary shower trailer that doesn't electrocute soldiers are ever involved in a technology like this the results are likely to be horrific. High amperage high voltage electric currents can be quite sneaky.

Have charging stations for fast 10 minute charges. Hook up the cables, slap in $6 for the cost of electricity, and get a cup of coffee while you wait. I think if people had that option, they wouldn't mind if their cars took overnight to charge at home.

for both smart grid technologies and approproiate vehicle charging infrastructure is needed.

Judging the future of a radically different energy infrastructure by current capabilities isn't the best approach.

Anything less than that probably means the power won't be working often enough to justify any new service connections.

I expect some wicked natural gas shortages are pretty damned inevitable at this point, especially if we start converting natural gas to liquid fuels, which seems pretty damned inevitable too. The natural gas power plant infrastructure is overbuilt. Nations that have a large surplus of natural gas are not going to be too keen on LNG exports when they can make more money exporting high quality diesel fuel with much less hassle.

I don't think a significant electric car infrastructure is in the cards. Future "middle class" status symbols are going to be things like fancy cell phones, laptops, sunglasses, and clothing, but not automobiles. Those will revert to being toys for the upper classes.

The die is cast. Battery electric vehicles have ended up as a integral element in a renewable infrastructure, and moving to a renewable infrastructure is the fundamental thrust of Obama's energy security, climate change, economic and foreign policies.

The debate is over. There are uncertainties in precisely how some sectors will be best served - for example, what combination of natural gas or biofuels will power our heavy transport sector? It isn't exactly clear since there is a competing demand from the electric generating sector for natural gas. However, that sector can also be served by biofuels since they provide the same advantage as natgas of being dispatchable.

We don't yet know how the carbon pricing mechanism will shape up, do we. We don't yet know how the domestic and international commitment to a carbon free energy world will affect deployment of alternative technologies.

We DO know that nuclear, wind, solar, wave/current/tidal, geothermal, hydro and biofuels can work together to meet our energy needs just as coal, natural gas, nuclear and hydro work together now to meet them. Within that context we DO know that electric vehicles are hands down the best replacement for the personal transportation sector.

It's just not practical.

Reality is gonna hit us in the head with a brick.

Now it's just throwing pebbles.