The Japanese can and are doing it, and have been for a long time. What would our
air smell like if we didn’t have millions of Hondas and Toyotas on the road? Let the Japanese foul their air with factories and build the cars. Send them all the raw materials they need.

The ‘Volt” is the final insult to the American
consumer. If they had spent half as much on development as they have on advertising this
(non)thing, we might already have one of their
paltry runs of proposed production. Here is one
area where they did not lie: their factories will
produce zero waste in the future because they will
not be producing anything at all.

The I’m a Naval Architecture/Marine Engineer wrote this I did not. I took this to mean one diesel could drive multiple generators. I did not correct generators to alternators nor Achitecuture to architect. I just wanted him to understand that one diesel driving multiple generators, the diesel would fail before generators, that probably would need grease for bearing and brushes/points replaced both easy on the fly jobs.

Geotpf : The Prius doesn’t get its efficiency on the highway from its partly battery driven transmission but from its shape. A car with Prius but not its weight due to extra gears and batteries would most likely be more efficient on the route between L.A. and las Vegas.

Or any safety measures. Or more than notional cargo room. Or acceleration. Downhill.

I wish people would stop dredging up the Metro as some kind of counterpoint. You may as well bring up motorcycles as viable alternatives.

Ummm, ok, you got me on that one. But it does not make sense, from an efficiency stand point, for engine -> alternator -> battery -> motor -> transmission. What would be better is engine -> alternator -> motor -> transmission. However, this second option (which is being proposed now) is still ridiculous – too many damn energy conversions/system losses!

blindfaith :

Oppps – I’m a Naval Architect (vs. Naval architecture …)

“I would believe the single point of failure is the diesel engine. I would also think the diesel engine when looking at MTBF would be 10x higher than the generators. The generators have perfect harmonic balance, no sludge ( during diesel combustion acids are created that literally eat through metal), this caustic dirty environment does not exist inside a generator.

I am confused.”

Just for clarity, the term generator refers to the engine & alternator package. I believe you meant alternator when you were mentioning balance/ sludge? Yes, the diesel engines are more maintenance intensive as compared to the alternator. With that said, I am confused as well … I’m not really sure what you’re getting at here. Could you rephrase your question/point?

Mannn, I love going off topic …

Wait!

Let me check.

Yup. It’s for sure.

The horse is officially still dead.

Whew!!

That was close!!

A turbo charged engine does not need mufflers.

You sound like my father law from Canton China. But, I believe you have a lot of rightousness in what you say.

I’m a company man working in the union. Find out what that means and you will validate your point.

Because they lied to us, man!!!1

I still don’t understand why I would want a Volt. We are told it will be in the $30 -40 K range. Expensive. Buy a Honda Fit, use the rest of the money for gas.

If you are homo econimus, then, yes, you’d skip the Volt at this price point. The first 10,000 are going to go to early adopters who want to stick it to the gas companies.

The price will need to come down for me to consider it, but I think it will, if not from GM than from another company.

The company isn’t going to pay for the power for 25 employees to plug in their cars, and is certainly not likely to set up a special electric car plug-in parking area.

Even at peak rates, electricity is still cheaper than gas in most circumstances. A 40 cent kilowatt-hour (a very high rate) will get you 5 miles. At $4 a gallon, you would need a 50 mpg car to get the same costs.

I would believe the single point of failure is the diesel engine. I would also think the diesel engine when looking at MTBF would be 10x higher than the generators. The generators have perfect harmonic balance, no sludge ( during diesel combustion acids are created that literally eat through metal), this caustic dirty environment does not exist inside a generator.

I am confused.

If we are getting about 60 mpg if you remove the battery weight. Then by all means sell it now without the batteries.

IF we are getting about 55 mpg with batteries in the Volt because they weigh 500lbs and cost $20,000 dollars why are you doing it? GM!

Just sell us the Volt without the batteries. It has always made more sense to run with electric motors with a tuned motor running in a specific RPM range. The why we haven’t is because nobody cared about the cost of gas. Nobody except cheap folk like me. If the engine was tuned to run on ethanol, the loss of mpg would disappear. Bye Bye OPEC

That is, the Volt doesn’t act like a hybrid (with most of the recharging coming from regenerative braking, which is free power) at all, but more like an electric car grafted on to a traditional gasoline one (although I’m sure even the Volt will use regenerative braking when the electric engine is working, but on long trips that will be for a very short time).

Is anything about this wrong? If it’s right, this is much worse for GM that I thought.

iganpo:

I’m a Naval Architecture/Marine Engineer and currently working on my masters. I would disagree with the captain. There are various factors on a cruise ship that make electric propulsion a good choice, but “fuel efficiency” is generally not one of them. The real reasons are:

1) High “hotel” electrical loads (the ratio of hotel electrical power to propulsion power is higher than that of, say, an oil tanker).
2) packaging – The generators on such a ship are powered by high- or medium-speed diesels, which are much smaller than the low-speed diesels on commercial ships (low speeds are the size of a house and generally turn at less than 125 rpm). The generators can be located anywhere in relation to the propulsors. Also, some of these ships are equipped with propulsion pods, which save a lot of space for other machinery and cabins within the ship (the latter of which = $)
3) Power flexibility & reliability – electric drive cruise ships have multiple generators, meaning that one, or even several, can be off line for times when (a) less power, or speed, is required, and/or (b) maintenance is required. A ship with fewer engines (as in 1 or 2) would be slowed significantly or completely for maintenance, which would be unacceptable on a cruise ship. Also, running engines at reduced/non-optimal loads is inefficient. On tankers/etc, the speed outside of the harbors is kept fairly consistent, and therefore the engine(s) run(s) very efficiently. During a cruise, people expect the vessel to stick to the schedule (especially when turn-around times in port are measured in hours). Therefore, extra power is needed at certain times. This is where multiple generators help – more speed needed? Just start up another generator (assuming the propulsion motors can handle the power). However, at the typical cruising speed, a direct drive would be much more efficient (from a fuel use perspective).
4) Marketing – Our ship has diesel-electric propulsion, kinda like a Prius! Also, the exhaust smells of roses.

Essentially, it all boils down to cost. Sure, a diesel-electric cruise ship uses more fuel, costs more to build, requires more maintenance, and has higher insurance premiums than an equivalent ship with a direct drive, low-speed diesel. However, the diesel-electric version can stay on schedule 98% of the time, has room for more cabins, and has a greener image (god, not that green washing BS again!). Also, low speed diesels do not need transmissions.

I’ll take a stab at the reason locomotives have electric drive: 1) the torque of the electric motor at low rpms, 2) i believe you’re right – no need for a 40 speed transmission.

ANYWAY, sorry everybody … back to our regularly scheduled program.

Sajeev: Judging by the home generator I used to power my house post-Ike, 3000-4000rpm is all you need for an ICE to power a generator.

Your generator at home runs at 3600 RPM because that’s 60 Hz which is what your home needs. It’s just easier to run the motor at the correct (or multiple of the correct) RPM and use the electrical output directly.

@Cavendel: I suppose the major drawback is when you’re sitting at a traffic light in your electric car, and the gas engine is roaring away at full throttle.

The cool thing is that if you maximize around one engine speed as the most efficient, then you can optimize everything else. If you know exactly that your engine speed is going to be in a very narrow range it’s trivial to design a muffler to take away all the noise. The reason standard mufflers don’t work great is that they need to work across all frequency ranges, get rid of that requirement and you’ll get lots of gains

I’d love a design where the ICE is either off or on at full throttle and that’s it (have the ECU manage that). When the ICE is off the car pulls all of its power from the battery. When the battery gets below a certain threshold the ICE kicks in and generates max power. Power can then go to the wheels from the ICE, what power isn’t being used for the wheels goes to the battery. When the battery is full the ICE shuts off. Rinse. Repeat. This way you have great efficiency from the ICE -> Generator -> Motor path, but you’re also getting ICE -> Generator -> Battery for the extra energy. And if the ICE isn’t enough for you can do Battery -> Motor. This allows for constant ICE power output and variable power use in normal day-to-day driving. I bet the (lack of) efficiency in storing to the battery will be made up from the gains in efficiency of running the ICE at constant power output.

As others have said above, diesel-electric locomotives and large ships have been doing this for years (sans battery) so the tech is there, it should even be simpler in a car since the power requirements are orders of magnitude less. In locomotives, they don’t (can’t) have a battery to buffer for variable power requirements, so what they do is run the diesel engine at variable power, but they do things like only have three speeds: 700, 1400, 2800 RPM. Since they’re all even multiples it’s easy to optimize the efficiency at those set engine speeds.

We are told it will be in the $30 -40 K range. Expensive. Buy a Honda Fit, use the rest of the money for gas.

We’ll also told that the Volt is of most usefulness for people who don’t drive very far – Less than 40 miles in 8 hours. Those are the people who have the lowest gasoline costs now. It will take them the longest (if ever) to recoup the extra expense of this high-tech drive train.

On the everyday practicality front, my commute to work is 19 miles each way. It’s true that the car will sit for 8 hours while I’m in the office, but there’s no place to plug the car in while I’m working. I suppose it’s possible that as a one-off geek, I might wrangle some deal, but if there were three people, then it would get complicated.

The company isn’t going to pay for the power for 25 employees to plug in their cars, and is certainly not likely to set up a special electric car plug-in parking area.

I’m still having trouble wrapping my head around who is going to buy this thing and how they are going to use it – except, of course, for the ‘gotta-be-cool” crowd.

If you haven’t driven a Prius, you just simply have to drive one to understand it. When you (subtly) feel the engine cycle on and off at sixty miles per hour you will begin to get the grasp of it.

It charges via energy reclamation, including at cruise from the motor-generators, not directly from the engine. The Prius does not treat it’s engine like a gas generator as the Volt would need to (but doesn’t), but it does treat it’s motor/generators and battery as a sink for excess energy.

My choice would be instantly….screw the gas whenever possible.

With the announcement that the gas engine will now be larger than originally stated, I presume the generator will also be larger, and perhaps this is not longer an issue. We shall see.

@Kevin: A few of us have proposed (mostly in previous threads discussing the Volt) that it ought to have an “extended trip” button to inform the car that the driver will definitely be exceeding the 40 mile electric-only range on this outing. That would be the only mode where the genset would attempt to keep the batteries charged on-the-fly.

Can I use “pw3d” in my next meeting? Please?

I actually like the Volt in principle. One nice point to the Volt’s architecture is that it’s relatively easy to swap in different batteries and engine/generators, where the Prius’ powertrain requires more engineering work. It’s more quickly adaptable to things like microturbines, diesel, small fission reactors, additional batteries.

In it’s niche, or with a better power source (or better batteries) it’s probably it best choice.

But yes, the Prius will pwn the Volt on the highway. It’ll cost less because of the batteries and because Toyota’s already paid for the R&D. The E-Flex system suffers from the same problem as Two-Mode does: it’s theoretically easier to repackage and redeploy for other implementations, but Toyota’s system is, real-world, a better system, especially in one-car situations.

GM is thinking about what’s easiest to reengineer and repurpose. Toyota is thinking about what will actually sell.

I think GM was probably going to do something like an E-Flex vehicle, but it was going to be a research princess like the HyWire or Sequel at best. The gas crisis and Toyota’s rising credibility forced them to put something into play. I’m also guessing that they’re having real trouble getting two-mode adapted to passenger cars, or we’d have seen it instead.

What this tells me is that this project is not nearly close to being ready for prime time. At the very least, it is going to be late, as it is already well behind schedule.