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Chevy Volt: Is This Our Future?

nytimes.com

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Re: Chevy Volt: Is This Our Future?

#81

Post by georgieporgie »

adrianN wrote: post #58
georgieporgie wrote: post #27

Earlier quoted context omitted.

30mpg highway is really good and does not reflect the average experience of a consumer. That said, I think you're (sadly) right, but not for the reason you're stating. Because electric cars can't be recharged in five minutes, consumers will suddenly think they have to go even further on a charge. They will completely ignore the fact that they commute 15 miles each way, every day, and the fact that they already have t…

What? 30mpg is around 7.8l/100km! All three cars I've driven so far consumed around 5 l/100km (gas) or around 4.5l/100km (diesel). All of them could seat four people and had enough room in the trunk to fit a week of groceries for four people.

That doesn't mean that American consumers expect 30 mpg from a family sedan on American highways.

Re: Chevy Volt: Is This Our Future?

#82

Post by acroyear »

tophat02 wrote: post #6
spiritomb wrote: post #4

Coal-Burning cars (er.. electric) are the future!

I've never understood this argument. I mean, yes, I get that all you're doing is moving the energy production somewhere else; but isn't that a GOOD thing? My response to the "you're just moving" argument is that you're doing more than moving it, you're CENTRALIZING it. It's much easier to replace one coal plant with a nuclear plant or a wind farm (or 10) than it is to replace the thousands of cars that plant powers.…

Not totally wrong. However, I don't like the idea of having my mobility tied to the grid at all times. Yes, oil comes from an economic grid of sorts as well (you can't easily produce it in your backyard) - but you can store gasoline more readily than electricity. I liken it to the problem w/ Walmart, i.e. the middle-men and distributed warehouses have been replaced by just-in-time (efficient) inventories. These systems are more efficient, but when/if they fail - they fail in epic fashion.

Re: Chevy Volt: Is This Our Future?

#83

Post by georgieporgie »

khafra wrote: post #69
georgieporgie wrote: post #44

Earlier quoted context omitted.

mid-range sedans can easily be driven into the 40s. Really? Here are some numbers from Kiplinger's "best midsize sedan" list from 2009: * Sonata 32mpg highway. * Mazda 6 30mpg highway. * Chevy Malibu 33mpg highway. * Nissan Altima 31mpg highway. http://www.kiplinger.com/columns/car/archive/2008/car1207.ht... Cars.com mentions the best in each class for 2011, and it's the Nissan Versa and Sentra, each at 34mpg for the…

Daimyoyo was talking about actual mileage, not EPA mileage. Simply by holding 60mph or below, you can easily get 10-20% above the EPA highway rating; 15-30% if there's a lot of traffic around you going the same speed.

It's funny you should say that, since I don't think I've ever known anyone to actually hit their EPA numbers. Then again, the EPA number calculations were recently revised.

That said, I don't consider driving <= 60mph to be 'easy'.

Re: Chevy Volt: Is This Our Future?

#84

Post by acroyear »

ChuckMcM wrote: post #41
bbg wrote: post #19

I want to love electric cars, but I see two big issues: (1) if they go mass market, all that electricity will still have to be generated somewhere. Coal? Nuclear? (2) The batteries need rare-earth minerals, which are brought to market through environmentally-degrading open pit mining. Furthermore, at this point, most rare-earths are available almost exclusively from China.

An internal combustion motor is, at best, about 20% efficient [1], whereas if you burn the same fossil fuel in an electric power plant using a combined cycle configuration you can reach 60% [2]. Now the electric company loses some of that by sending over wires to your house (or where ever the charger is) but its still a big win. What that means in mathematical terms is that if you took the same fossil fuel we burn to…

JEVONS EFFECT

Re: Chevy Volt: Is This Our Future?

#85

Post by acroyear »

acroyear wrote: post #82
tophat02 wrote: post #6

Earlier quoted context omitted.

I've never understood this argument. I mean, yes, I get that all you're doing is moving the energy production somewhere else; but isn't that a GOOD thing? My response to the "you're just moving" argument is that you're doing more than moving it, you're CENTRALIZING it. It's much easier to replace one coal plant with a nuclear plant or a wind farm (or 10) than it is to replace the thousands of cars that plant powers.…

Not totally wrong. However, I don't like the idea of having my mobility tied to the grid at all times. Yes, oil comes from an economic grid of sorts as well (you can't easily produce it in your backyard) - but you can store gasoline more readily than electricity. I liken it to the problem w/ Walmart, i.e. the middle-men and distributed warehouses have been replaced by just-in-time (efficient) inventories. These syste…

also, don't discount the Jevons Effect .. another complication that has to be taken into account.

Re: Chevy Volt: Is This Our Future?

#86

Post by khafra »

georgieporgie wrote: post #83
khafra wrote: post #69

Earlier quoted context omitted.

Daimyoyo was talking about actual mileage, not EPA mileage. Simply by holding 60mph or below, you can easily get 10-20% above the EPA highway rating; 15-30% if there's a lot of traffic around you going the same speed.

It's funny you should say that, since I don't think I've ever known anyone to actually hit their EPA numbers. Then again, the EPA number calculations were recently revised. That said, I don't consider driving <= 60mph to be 'easy'.

There's a good reason I said "simply" instead of "easily." I'm personally planning some mild aerodynamic modifications to decrease the 75mph cruising penalty.

But I was referring to the current EPA numbers; the pre-2007 EPA ratings are harder to exceed by such large percentages.

Re: Chevy Volt: Is This Our Future?

#87

Post by stellar678 »

Derbasti wrote: post #67

Can someone explain to me, why, exactly, this should be better than a hybrid design? A hybrid design can use a comparatively tiny combustion engine together with an electric motor, which saves fuel consumption and does not need to be plugged in ever. The Volt needs both a full-fledged combustion engine and a full-fledged electric engine and needs to be plugged in after each drive. That sounds basically like combining…

In discussions about electric cars there always seem to be two arguments that end up head-to-head:

1. That average or mode of distance traveled per day is less than X miles. (60 or something, a distance many electric car designs have no problem achieving) 2. That people won't accept a car that can't do long-distance trips.

The Volt/serial hybrid (which Volt actually isn't) design responds to both of these arguments. If we transitioned all cars on the road to this, the average drive wouldn't consume any gasoline at all but people could still take their infrequent longer road trips.

That's the premise I've seen at least.

Re: Chevy Volt: Is This Our Future?

#88

Post by ChuckMcM »

adrianN wrote: post #56
ChuckMcM wrote: post #41

Earlier quoted context omitted.

An internal combustion motor is, at best, about 20% efficient [1], whereas if you burn the same fossil fuel in an electric power plant using a combined cycle configuration you can reach 60% [2]. Now the electric company loses some of that by sending over wires to your house (or where ever the charger is) but its still a big win. What that means in mathematical terms is that if you took the same fossil fuel we burn to…

When calculating the efficiency of electric cars you must also take into account the losses from the battery. I'm pretty sure charging a battery is not 100% efficient.

Absolutely, the electricity -> chemical -> electricity cycle gets less power out than you put in.

The fuel cycle is still fossil fuel -> (stuffs) -> car moves.

There are many ways to change around the (stuffs) part of the equation. The claim is that converting fossil fuel to electricity in bulk is much more efficient than converting it into mechanical work locally through exothermic chemical reactions.

We could keep trying to detail efficiencies (or non-efficiencies) in the problem but as Glieck pointed out in his Chaos book, you can compute the length of the British coastline by drawing a line around the island and get one number, or you can zoom in and include the bays and harbors and protrusions and get another number, all the way to going around each grain of sand on the beach and getting yet another number. Clearly the closer you look at the coastline length the 'longer' it gets, but that extra length is misleading.

Re: Chevy Volt: Is This Our Future?

#89

Post by georgieporgie »

khafra wrote: post #86
georgieporgie wrote: post #83

Earlier quoted context omitted.

It's funny you should say that, since I don't think I've ever known anyone to actually hit their EPA numbers. Then again, the EPA number calculations were recently revised. That said, I don't consider driving <= 60mph to be 'easy'.

There's a good reason I said "simply" instead of "easily." I'm personally planning some mild aerodynamic modifications to decrease the 75mph cruising penalty. But I was referring to the current EPA numbers; the pre-2007 EPA ratings are harder to exceed by such large percentages.

There's a good reason I said "simply"

Uh...

you can easily get 10-20% above the EPA highway rating

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