Hybrids like the Prius use the electric motor to help out the internal combustion engine. The Volt uses only the electric motor to turn the wheels, and the IC engine acts as a generator, running at a constant rpm to supply electricity when the batteries become too drained.
Why was the method of having both motors run the wheels chosen for the first hybrids rather than the Volt’s method? It isn’t a new concept, and would seem to be simpler.
Would a car that uses a generator to power an electric motor get better mileage than a standard internal combustion car? I think the Volt is supposed to get 300 miles on a 6 gallon tank, so it would seem to be better due to increased efficiency, but it might also benefit from being engineered to get the most distance out of the batteries.
Even if you left the batteries out altogether, would there have been a benefit to building gas-powered electrics all along in mileage, performance, maintenance, reliability?
I don’t know why the big car manufacturers didn’t do it that way, but I’ve seen a homebuilt car do exactly that. I forget what kind of car they used (some small 70’s or early 80’s car - this was a while ago), but they yanked out the engine and put an electric motor in its place. The car was powered by a bunch of regular lead acid car batteries, and a very small gasoline engine (I think from a lawnmower) could be used to charge the batteries. It was a prime example of hillbilly engineering, but it worked and I think the “conversion” to electric cost the owner about $5,000 total. I don’t believe that he used regenerative braking at all.
I always thought it was odd that the big car manufacturers did it the other way around.
The Volt is, I believe, a descendant of the EV1. Other companies started with a different starting point and developed their technology to perfect the flaws in their respective systems. Flaws might be issues of user friendliness, manufacturing costs, reliability, etc. But if they swap to an entirely different technological base, they’ll have another 5-10 years that they have go through test models, tweaking, and perfecting before they have a marketable vehicle. They’re better off to carry on with the technology they have and understand.
I’ll also note that, quite possibly, there could be some patent issues in there. GM might hold some patents that would be prohibitive to go around and achieve the same end result.
[nitpick]The Volt uses the same type of serial hybrid as the Volvo Environmental Concept Car of 1993, which was the first car of this type. [/nitpick]
So why didn’t the Prius go this route? Dunno. Different engineering approach I guess.
Not necessarily. With a serial hybrid the ICE can be operated at its peak rpm and load where if the ICE is directly connected to the wheels it has to operate at a variety of rpm/loads. A serial hybrid also does not need a gearbox.
Serial hybrids have been in existence for a very long time in the form of the diesel-electric train:
Probably so they could get away with a smaller motor. Not only are smaller motors lighter and cheaper, but it also reduces the engineering challenges for the control electronics. The current Prius has a 60 kW motor, and the first-generation Prius had a 30 kW motor. The Volt has a 111 kW motor.
Its not about mileage its about convenience and marketability. The Prius isnt an electric car, its a hybrid. Its a fancy pants gas car. The volt is a real electric car. The idea behind it is that you dont just put gasoline into it every week, but you should be charging it every night or every other night. The gas engine is just for emergencies.
Essentially youre asking why hybrids exist. They exist because they are marketable and get good MPG, but they are not traditional electric cars like the Volt. If I was to buy an electric car I would consider the cost of putting a 220v plug near my parking spot as part of the deal. I would not consider buying gas weekly to be acceptable or attractive.
Not necessarily. Whatever the configuration, the engine needs to be big enough to supply the average power required for a trip. The Volt has a 1.4-liter engine and the current Prius has a 1.8-liter engine (previous model had a 1.5-liter engine).
Actually I am asking why a series hybrid doesn’t already exist (aside from the Volt). Disregard any desire to get power from sources other than gasoline, whether or not battery technology is up to the task, etc. Is it mostly a matter of manufacturing going the way of ICE and building on established technology? Or does series hybrid have some inherent disadvantage that has made it not worth pursuing until now? (Now having been 1993 for Volvo).
Also the Volt isn’t a traditional electric car (like the Tesla). The battery pack gives you the option of never buying gas if you don’t want to, like a vegetarian who orders salad at a steak restaurant.
As more options become available, I wonder if there will be labels for people who have particular principles on the consumtion of energy. Perhaps there will be EV-gans who refuse to buy gas on moral grounds. If they can’t get there without using fossil fuels, they won’t go. EV-egetarians who will still take a plane or ride their friends ICE vehicle, and series-hybrid owners who avoid gas as a rule but are willing to burn it on occasion.
I think the question is best asked just comparing series to parallel hybrids assuming neither goes off of grid derived power at all or each uses the same amount.
I don’t know the answer though. The series approach allows for an engine to operate only at fairly ideal efficiencies (and even allows for other sorts of engines, like microturbines), but it adds an extra power conversion step too …
True, but you still need a battery to store the excess generated electricity. Without it, you have to size your ICE for peak load (vs. average load), and you’ll end up with worse performance than a straight ICE->wheels car.
So it makes sense for my 32 mile rt commute. But is there an electric/hybrid which makes sense for long-distance driving? It seems to me that the ICE->wheels drive train is the only one which can accommodate both.
I’d love for my next vehicle to be electric, but not sure I want to rent every time I go to visit family.
The Chevy Volt will switch to ICE after the 40 mile mark and still get very good economy (claimed to be better than Prius, so 50+ mpg). Range on a tank of gas is 600 miles and after that you can just fill up the tank and continue. The idea is to plug it in at night and do your commute on electric and than have conventional range and convenience for road trips. If they can make it work as well as they claim I think they have a winner.
Toyota says it will release a plug-in Prius in 2010. At that point, the distinction between parallel hybrid (Prius, etc.) and gasoline-recharging electric (Volt) becomes pedantic.
I can’t find it, but wasn’t there a gas-recharge electric car made in the early 20th Century? Or am I thinking of Diesel-Electric trains and submarines?
Not quite so pedantic. There is a difference between the Volt’s estimated 40 mile all electric range and the Prius’s estimated 12 mile one. And the 2010 PHEV Prius is for limited fleet sale only.
This decision however may reflect less an intrinsic difference between serial vs parallel hybrid technology, than the fact that Toyota is married to one battery company and that they have been late to the lithium battery game.
BTW here is more about optimizing the ICE for efficiency in a series hybrid.
And GM’s take on whether or not a series or a parallel hybrid architecture is intrinsically more efficient if you factored out using grid-derived power (the op’s question):