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> I believe this is what Chevy Volt does

The article's point is not to about "diesel-electric" systems (where the ICE acts solely as a prime mover for a generator and the wheels are always driven electrically). That's old news in both transportation in general (it's been in use in trains and ships since the early 20th century) and in hybrids ("diesel-electric" is sometimes called "series hybrid" or "range-extended electric vehicle" in cars).

It's about a new engine design[0] where electric generation is merged into the piston itself: a "normal" diesel-electric engine has a regular diesel engine (or more generally ICE) with pistons driving a crankshaft which drives the driveshaft, which is connected to a generator.

Here the design does away with the crank and driveshaft: the piston itself is a rotor, and the casing becomes the stator, doing away with mecanical transmission altogether: the piston and its cylinder become a linear generator.

[0] not quite that new, the first patent on free-piston engines[1] for linear generators dates back to 1959. The new part is getting a design to actually work in a vehicle[2].

[1] a free-piston engine is an engine without a crankshaft transforming the piston's linear movement into rotational movement

[2] the crankshaft does not just transform motion and lose energy, it also synchronises pistons and limits the piston's course. But if the piston+cylinder is a self-contained generator, I guess you can treat each piston as a single-piston linear engine? Which would limit the usual issues of multiple free-piston engines.

edit: formatting, footnotes

Thanks for the explanation.

This article is more about using the linear electrical generator on the piston than it is the configuration of the power train. No vehicles on the road today have anything similar to what is discussed in the article.

Also, I'm not sure about the current model, but there was a bunch of kerfuffle over the Volt not really being a strict electric hybrid:

http://www.plugincars.com/exclusive-chevrolet-volt-chief-eng...

Some of the time, at least in the edition discussed there, energy from the engine goes to the wheels without ever becoming electricity. Maybe they changed it in later models (but I sort of doubt it, the capability is there because it can be the most efficient way to use the engine).

I did not know that. Looking at the Wikipedia article for the Volt [1] I can see that the gasoline engine may provide additional mechanical energy to turn the wheels, but it's only to assist the primary and secondary electric motors.

In either case, I am not a purist going after a 100% electric car. I want to get more miles per dollar, and I want to produce less CO2 per mile. The Volt seems to do that, while still letting me drive from NYC to LA and back without having to spend more than three minutes at any given gas station. More importantly, any gas station will do, since it can run on just gas. For a daily commute, it will likely run 100% electric since the battery won't be depleted. To me, this is a great combination.

[1] http://en.wikipedia.org/wiki/Chevrolet_Volt#Drivetrain

Nothing in your first paragraph is special to the Volt. Any hybrid, aside from the less advanced "motor assist" designs (found in earlier Honda hybrids) get the same advantages. A Prius can keep the engine at a happy RPM throughout due to effectively having a CVT, and it can not only shut off the engine when stopped, but even when moving up to 40+MPH.

There are some interesting consequences of a pure serial hybrid design like the Volt (although the Volt isn't quite a pure serial design), but friendlier RPM and the ability to shut the engine down aren't it.

It's simple: A car needs a source of energy. Then a 15 gallon tank of gasoline is just super tough to beat. Can beat it a little with a 15 gallon tank of Diesel oil. A few hundred pounds of batteries with a charge from the electric grid? You gotta be kidding.

Now, what to do with that liquid in that 15 gallon tank is a question, but the basic fact remains. Did I mention that that fact is simple? A car needs energy, and that 15 gallon tank is tough to beat. For the rest, we have a lot of possibilities, but that 15 gallon tank is tough to beat.

Gee, some people need some help: Did I mention, a 15 gallon tank is tough to beat? Electric power, that is, without a tank of gasoline or Diesel, for the energy for a car, is tough, super tough, for now and a long time, too tough to store. It's tough. Storing electric energy is tough, too tough for a car and likely also for wind and solar to feed the grid. Yes, there are ways to store the energy from wind and solar for the grid, but those ways are too expensive, by a factor of about 2, over other means of electric power generation that do not need storage, even if the power from wind and solar are just free, as in totally free, as in $0.00 per megawatt year.

So, let's look at an example, say, Tesla. I just went to their Web site and looked at charging time and saw

> During the work week I charge only at work during an 8hr shift from a 110 outlet. I only live 6 miles from work. I usually get ~30 miles of charge in 8 hours

So, right, 8 hours of charging for 30 miles of driving. Lots of cars can go 30 miles on one gallon of gasoline that takes about, what, 20 seconds, to pump. Diesel, maybe 45 miles.

The car, sure, it can still drive the wheels with electric motors, but, to make any sense, we store little or no electric energy in the car. Instead, the energy for the car is stored in a 15 gallon tank of gasoline or Diesel.

We had electric cars going way back to the beginning of cars. Why? Because lead acid batteries and electric motors were already old things. And, a battery much better than lead acid is still tough to get; indeed, we still use lead acid batteries in cars for, say, the starting motor.

The main problem with electric cars remains the batteries. As a Ford executive said long ago, build me a good battery and I will build you a good electric car. We are still waiting for a good battery, say, comparable with a 15 gallon tank of gasoline, in range, capital expense, operating expense, durability, and 'recharging' time.

So far, a Tesla is a toy for rich people. Sorry 'bout that.

I could like an electric car; it would have a lot of advantages. The problem is the battery. And that's been the problem for about 100 years.

Nothing in the grandparent comment invites your first rant. Except maybe I do happen to think that the Volt is the best compromise between price, range on batteries, and ability to drive long distances., but that doesn't exhibit any of the confusion about batteries vs fuel that you seemed to think you were responding to.

I imagine the people clicking the down facing triangle were responding to your unnecessary and out of place tone, not out of Tesla exuberance.

The free piston engine that is essentially a linear electric power generator in the OP is interesting and maybe promising for practice. And such a car with a battery for capturing energy from braking, operating accessories without the engine, and some extra power for a few seconds could be fine. Fine. I like it. Good OP.

You wrote:

> Nothing in the grandparent comment invites your first rant.

Wrong. From the OP I was responding to:

> Electrically driven cars are the future. But until we have cheap, 1000-mile batteries, we still need range-extending fossil-fuel engines.

This quote is the "rant" -- the writer hates "fossil-fuel engines" and is dreaming of "1000 mile batteries" presumably to be charged from the electric grid. Wacko nonsense. Smoking funny stuff nonsense.

Uh, just where would the energy to charge a "1000 mile battery" come from? Sure, now, heavily from the electric grid from fossil fuels. Wind, solar? Nope, not for the grid because those sources will need to store electric energy, and that's too darned expensive.

Some people just HATE a 15 gallon tank of gasoline or Diesel and just dream of "1000 mile batteries" and threaten to increase my costs of car travel and seriously weaken the US, and I don't like attacks on either me or the US.

This wacko, 'green worship' with humans and carbon as 'evil', etc. is going too darned far. I don't care about people worshiping the moon, but this wacko stuff is trying to hurt my car transportation, and I don't like it.

Reconcile your impression with what they say here:

https://news.ycombinator.com/item?id=7977031

They also don't actually say the words you have put in quotation marks, or anything especially dreamy about electric cars. Maybe they said it somewhere else?

(I suppose 'less carbon' could be characterized as dreamy, but electric miles are often cheaper to operate, so I guess I don't like that characterization)

Anyway, I don't mind if you agree with me about whether the comment invites your response or not, I just wanted you to consider that maybe the people who inspired your second rant did understand your comment and downvoted for other reasons.

Ah, come ON.

The original post is the article

Jason Cammisa, "No crankshaft, no problem: Toyota's free piston engine is brilliant: Gas piston engine fundamentals haven't changed in 134 years—until now.", 'Road and Track', June 30, 2014.

at

http://www.roadandtrack.com/go/out-of-turn-toyota-engine

and the third paragraph starts with just what I quoted, exactly, again, yet again, one more time, exactly, precisely, every character right in place:

> Electrically driven cars are the future. But until we have cheap, 1000-mile batteries, we still need range-extending fossil-fuel engines.

Again, the work by Toyota looks good, and the article is somewhat interesting, but apparently the author wanted to insert a line to please the greenies so put in his "1000-mile batteries" and his swipe "fossil-fuel". Apparently with a little more encouragement he could have put in some words about evil humans and filthy CO2 and the dangers of 'global warming', rising sea levels, massive deaths of wildlife, the melting of Greenland, and 'climate change', that is, each tornado, hurricane, flood, drought, snow storm, especially hot/cold day, week, season, etc. I'm SICK of nearly constantly being beaten over the head for no good reason by this non-stop propaganda of total incompetent, made-up, hysterical, guilt-ridden, dysfunctional, destructive, dangerous nonsense.

This propaganda is trying to build a political consensus to get on my back and into my wallet and seriously hurt the US, and I don't like it.

I don't know who or what is paying for or pushing this propaganda, but I'm pushing back at it.

They also don't actually say the words you have put in quotation marks,

Okay, I guess I misunderstood that your comment that was posted as a child of a comment was not actually a response to that post (I would guess that most other people made the same error...). Or are we supposed to tease out what part of the invective is directed at the parent comment and what part is directed at the overall story?

My bad substituting "carbon" for "CO2".

I didn't know the 'hierarchical' norm of implied references and, instead, thought that all the posts were about or at least in the context of the OP unless carefully stated otherwise.

For the guy with his Chevy Volt, fine.

I think if you are going to post a rant about the linked article, it's pretty appropriate to post it at top level, or at least as a reply to a comment with a lot of context.

I also think it would be more useful to post a thoughtful, persuasive comment (as opposed to saying 15 gallons multiple times), but that's a different issue.

Anyway, this whole sub thread is sort of unfortunate (in that we both wasted time and any unfortunate bystanders wasted their time too). Oh well.

I don't recall just why I posted just where I did in the tree, and I'm not going to waste any more time to look.

The 15 gallons thing is because I'm pissed at this greenie stuff and need to pound and pound on the rock solid, dirt simple, overwhelmingly important fact that the whole greenie thing is trying to beat a 15 gallon tank and has essentially no chance of doing so and, thus, is really dumb and much of why I'm pissed. I continue to be attacked here because of 15 gallons, and that shows again, yet again, once again, over again that even something as simple as a 15 gallon tank is unacceptable to the greenies so devoted they are to their irrational religion. The greenies can go worship the moon and I won't care, but they are a threat to my car and to the strength of the US, and I'm pissed, as nearly everyone in the US should be. This greenie stuff is wacko.

Yeah, I understand not wasting any more time on this thread.

You aren't getting attacked because you said 15 gallons though, people are down voting your posts because they don't add much to the conversation. You're imagining some motivated contingent of people voting against your posts because they speak the truth about the article, but really, your first post was down voted because it was somewhat obnoxious.

I mean, are you commenting here because it is a convenient place to propagandize, or are you commenting here because some decent and interesting conversations take place? If it's the latter, then you have a reason to make a better effort than making sure that your views get equal time propaganda. I realize that sounds preachy, but I'm too lazy to figure out how to better put it.

> I only live 6 miles from work

Why'd you use a car then? That's a very nice bike ride. (I'm from The Netherlands so excuse my ignorance if there isn't even a physical way to bike around your area).