What about gasoline powered alternatives?

[PaoCivil]

What do you guys (auto experts) think about Hybrid or electric cars? How far are we from making that a daily reality? and What would be the benefits for our country if we implement that technology??
Thanks

 

[GregLocock]

Well electric cars seem to be a bust, GM has just canned the EV1. That is a shame, with the NiMH batteries it certainly had good enough range for a commuter car.

Still, basically it was always going to be an expensive replacement for a gasoline car, due to the replacement cost and frequency of the batteries. Also it does nothing, or very little, for overall energy useage, and hence global emissions, unless nuclear power is used for electricity generation.

Hybrids have a little more going for them, but I wouldn't mind betting that a sensible diesel in the same car could offer equal emissions, consumption and performance, and would be substantially cheaper.

Cheers

Greg Locock

 

[GraviMan]

In the end fuel cells will win out on maintenance and cost grounds. Hybrids are a great interim solution, while solid state "engines" are developed. This ain't gonna happen overnight! ;-)

Mart

 

[evelrod]

This is just my opinion but, the current trend by OEMs toward hybrid technology is more a political statement than a practical effort at solving the air quality concerns of the general public. The relatively high buy in, the high cost of maintenance (battery replacement in 3 to 5 years being a given) and, the attendant lack of resale value will ultilmately kill the hybrid as it is now configured. As to fuel cell technology---future potential is outstanding, the FAR future. With no infrastructure, no practical reformers/storage systems, no costeffective fuel cell technology---Good idea, just not in the near future!
With an advance in battery technology, vis a vis, cost, size/weight, longevity , etc. it is concievable that a vehicle such as the EV-1 may surface in a cost effective vehicle in the near future, just not probable. I live in SoCal where the electric car/truck is being/has been, tested extensively. The "suggested" drive time charge is most often VERY optomistic and that leaves these vehicles "stranded" more often than not. Like I said, "political". A long way from a practical solution at present. However, it has been said before, but "If we can put a man on the moon..."!

Rod

 

[MadJac]

It is indeed a shame GM dropped its electric alternative. I was reading a few weeks ago that a Japanese university (Tokyo if memory serves me) designed and ran a full size limo at 120MPH...pure electric. The idea was to set aside the myth that you can't have speed and ecology in harmony. I do not recall the longevity of the batteries nor the distance of the run....but...120 on electricity has to count for something. No I do not hug trees in my spare time. I just find pushing the edge of the envelope for the sake of pushing the edge of the envelope to be interesting if not fascinating most of the time.

 

[schwee]

I think hybrids will win out. Fuel cells are indeed WAY out in the future and may not offer improved efficiency over a high-output IC engine. I think a committed effort to produce an "extreme" hybrid -- flywheels, free-piston IC linear alternator, connected in series to power-dense DC brushless motor(s), will beat a conventional diesel due to no idling and regenerative braking, as well as no transmission, crankshaft, or connecting rods. The very high torque and short-term power of the electric motors will easily beat the performance of an IC diesel, and the linear alternator can be run at peak efficiency at all times, and is possibly up to 20% more efficient than a diesel anyway (runs at at least a 30:1 compression ratio, for instance). I belive a test alternator runs about 500cc or less, with an output of 40 kW, and a total weight of 60 lbs.

The point of a hybrid is to reduce the power needed from the engine (APU), and thus its weight, and to use some sort of power storage mechanism for peak power needs such as accelerating, passing, and hill-climbing. I don't believe existing schemes to do this, as exhibited by the Prius and Insight, commit to this philosophy to a sufficient degree to make them viable. Basically, their engines are too big, their electric motors are way too small, and their batteries are far too heavy and not power dense enough to serve their stated purpose of high-power bursts for short durations.

To do a hybrid right, I believe you have to put your money where your mouth is. That is: one of the major reasons, if not the major reason, for a hybrid, is to utilize the fuel-consuming APU at maximum efficiency at all times. A parallel hybrid can't really do this -- electric motors can "smooth," but not eliminate, fluctuating power demands, and the engine must spend a considerable portion of its time running at non-optimum speeds and outputs. An "extreme" hybrid commits to this principle, and runs the APU at peak efficiency at all times, or not at all.

The only way to make this work is to have a power storage system capable of handling very high power demands for short runs, capable of near-instantaneous, low-loss recharging from engine and regenerative braking, and able to handle an almost infinite number of deep discharges. This power system must also be fairly light, or it will defeat the purpose of the hybrid. I am pretty sure batteries will never, ever fit the bill. Their energy density is decent, but their power density is really poor, and their charge/discharge times are just unacceptable for a vehicle application.

Clearly, I am a flywheel enthusiast. Flywheels can deliver essentially unlimited power for the durations needed for almost all small vehicle applications. They recharge almost instantly, can discharge very rapidly, and can withstand essentially infinite deep discharges. Outfits like AFS Trinity, Lawrence Livermore, FESI of Ottawa, Canada, and the University of Texas have already built and tested flywheels of a suitable size and power output for hybrid vehicle applications, complete with sophisticated electronic contols for managing power input and output. Coupled with Sandia's free-piston HCCI linear alternator, and something akin to UQM Technologies' INTETS DC brushless motor, you have, in theory, a very high-efficiency series hybrid with performance significantly better than most sporty cars presently on the road, with twice the mileage and half the emissions.

The remaining problem is the body and, more significantly, flywheel ballistics containment in the event of a rupture caused by overspin or an accident. This is not trivial: particles of carbon fiber and epoxy fly off a flywheel in a rupture event on the order of Mach 5 -- a single flywheel sufficient to power a hybrid vehicle contains enough energy to blow a Corolla-sized car a mile straight into the sky.

And yet, a gas tank full of ten gallons or so of highly refined, volatile gasoline is a pretty scary proposition, too. You can do it wrong, and produce an unacceptable risk, as in the Ford Pinto -- or you can do it right, such that your car will probably not explode unless hit by a train.

In doing it right, it sure seems to me that enough smart people working on the problem can nail it down. We have Kevlar. We have lots of ballistics containment folks in military pursuits. And we have Burt Rutan, who knows enough about lightweight composites and structural engineering to build a plane that flew around the world without refueling, and to build the GM Ultralite concept vehicle, far and away the lightest, strongest, and stiffest monocoque car body ever created.

An extreme commitment to a true hybrid, I believe, will produce something truly remarkable, rather than the half-hearted and ultimately doomed efforts we see now. The thing must be very light, and very strong, both to handle flywheel containment and to take advantage of the true hybrid concept of light weight and high short-term power. This means a composite monocoque body, probably with flywheel containment integrated into the design for increased strength and stiffness. It means a commitment to the original vision of a hybrid -- run the fuel engine at peak efficiency at all times, and use only electric motors for propulsion and regenerative braking. This committment gives the added benefit of doing away with the need for a multi-gear transmission, as well as connecting rods and crankshafts -- the linear alternator uses neither of these. Moreover, it uses the innate capability of electric motors to generate very high low-end torque, which they do much better than all IC engines.

While this setup is designed for efficiency and low emissions, it would seem to me to have an added, and perhaps unintended, benefit: namely, really incredible performance, particularly in terms of acceleration. A commitment to light weight could result in a race car of perhaps 1,000 lbs, with perhaps 300 hp for ten seconds or so. Distributed to four wheelmotors, using automatic torque control to prevent burning rubber, that should result in 0-60 times that are, well, neck-snapping. The world record for autos now seems to be under 2 seconds -- this hybrid, applying all the smooth power and torque its tires can handle, and weighing about a third as much -- could very conceivably beat that. Handily.

Granted, it won't win LeMans, or Indy, and it won't pull very heavy loads up long, 6% grades in the Andes. But it WILL turn heads, in the most elemental of high-school teen fantasy kind of ways -- by taking off from a stop sign like a rocket and blowing the doors off of anything and everything misguided enough to try to match it. To me, there is little point in this -- the real world doesn't need rocket acceleration. But gearheads seem to like it, and some gearheads, like Jay Leno and Paul Newman, like it a whole lot and have a whole lot of surplus cash to indulge their fancy. Ditto many testosterone-charged CEOs who would welcome an extremely fuel-efficient and envirnmentally friendly car (great PR!) that just happens to have world-beating performance, at least in the world they actually live in -- tearing out of stop signs and clobbering Ferraris and Lamborghinis going up short climbs on the coastal highway.

That is to say, certainly, the research and development costs of an "extreme" hybrid are prohibitive -- in the short run. But much of the whole point of racing and making a splash in the automotive press is PR and image. You make extremely expensive, extremely high performance cars to tickle the imaginations of your buying public, and sell them vastly cheaper and less high performance vehicles of the same name that they can actually afford. By going after the extremely high-performance, expensive market, you build up demand for your product, instead of relying on committed environmentalists willing to put up with poor performance, high cost, and high maintenance expenses, as is presently done with the Prius and Insight. A successful hybrid can't make such extreme compromises -- it must be composite, it must use flywheels, it must have a radical, experimental IC engine, and it must commit to big, powerful electric motors. Way too expensive now, but not so when people begin packing the wailing lists for the amazing screamer that everyone's abuzz about -- 0-60 in 1.5 seconds and 200 mpg. THAT is why hybrids will win.

 

[evelrod]

Hmmmm! 0 to 60 in 1.5 seconds, eh. 200mpg?

I was ok up to that point. I have seen a 200mpg car on TV in a Shell commercial (years back) and I have seen "cars" go 0 to 60 in a second or so but---a street car that can accelerate 0 to 60 in one and a half seconds at ANY fuel mileage becoming THE car to have and drive around town?
Hey man, the fools are killing themselves with bone stock Toyotas and Hondas now. Before ANY of this new technology hits the market (?) we need to serioulsy address the DRIVER LICENSING and DRIVER COMPETANCE aspects of OUR future if we want any of this to work.

Sorry, but what you have posted here and in several other forums sound pretty far out there as it pertains to the real world. Perhaps all this "flywheel" technology will work, perhaps it is just another 'far out' idea. I can't read the future but, if I could I would be surprised at what I would find as "personal transportation" in 20 years!

Make it work! Find someone smart/rich enough to make it work. Get a working model out there and if it really is as good an idea as you claim...!

Rod

 

[ivymike]

re a couple of posts up, 120mph electric-only is not an electric vehicle speed record, by any means. There was a slightly modified EV1 that went about 180mph in 1996 or so, if memory serves. That was a new ev speed record at the time.

 

[schwee]

Hi, rod --

Well, I may indeed be too far out there. In trying to whip up enthusiasm I may be trying too hard. But I can't see why near-burning rubber on four wheels with a car about a third the weight of typical race cars can do anything but be faster. You can't GO faster -- to accelerate faster, you'd have to make it lighter.

And my idea isn't at all to even try to make a high-performing, specialty car into a street car. It's a race car. Perhaps it's not even a "car" -- I would even go so far as to pull the APU from such a car and just run it from the flywheels -- range, one drag strip run. Then plug into the wall to recharge. Maybe something similar for trying to show off in something like the Pikes Peak hillclimb. Why not? These "conventional" specialty cars aren't really "cars" either -- take 'em on the street and they'll probably blow up in a day or two.

And perhaps 200 mpg is unrealistic. Good ol' Amory Lovins claims 300 mpg on existing technologies, but he may be even more wacko than I am. Of course, you can rig mileage figures, too -- an APU-less flywheel dragster gets infinite mileage, for instance.

If one were to sell the hype, one would probably make such claims. Being as this is a forum of engineers rather than dopey citizenry, it might be best to reveal the wizard behind the curtain.

The thing that goes (let's say) 0-60 in 1.5 seconds, or whatever, may not be the same one as the street car that gets 200 mpg. Or it might -- but it can't do the 1.5 seconds very many times before you melt the motors, since you deliberately took off the current cap on the motors to get the record. But the idea is there -- prove to someone that you can do both the acceleration and the mileage, and don't tell them that you had to replace the motors the next day.

Sigh. It's still gonna get great mileage and great acceleration. It has to, by its configuration. And 200 mpg isn't crazy -- somebody -- BMW, I think -- got 370 mpg or something, I read recently. Don't know what wizardry they were up to, but probably something. A gossamer bicycle, perhaps.

OK -- so do it. Well, see, I have like, zero money. Also near zero credibility. I am in fact, since I am unemployed, working pretty hard at it. I've put in at least 80 hours this past week, sending stuff to a flywheel manufacturer in Mexico, flywheel researchers at Texas and Berkeley, reluctance motor guys in Indiana, and about six or seven other leads. I tend to get lukewarm reactions -- people are into their own thing.

My next move is to see if I might contact Leno. He gets his Bugattis worked on at a shop just up the road -- my neighbor is a lead mechanic there. I'll see if he might put in a word. I suspect that the "smart" and the "rich" don't generally come in the same package. I've been pursuing the "smart" -- maybe it's time to pursue the "rich" first.

 

[evelrod]

If you find the secret to getting the "rich" to invest (they are usually pretty stingy) let me know. "Evelrod Racing" and the "Money Pit Mini" could use a new sponsor (indeed, ANY sponsor). A "pearl" I used on another thread seems equally at home here---"I started out with nothing and I still have most of it".

Rod

PS I have a few very rich 'friends(?)' It is nearly impossible to truly have friends that are at opposite ends of the $$$$$$$$$$ spectrum. I lost an engine in Mexico City once and they just could not understand why I didn't have a new one flown in!!!

 

[JayMaechtlen]

the way I see a couple of things here-
"Hybrid" = some combination of engine(fuel burning device of some sort) + energy storage/retrieval system.

The engine can be anything that makes power on ongoing basis. Not batteries or flywheeel, but could be a diesel (with or without turbo or other enhancements), or a standard gasoline engine of whatever persuasion, or a Wankel, or a free-piston linear alternator, or...
There may or may not be a mechanical power flow between the engine and the ground. If there is, it is a parallel hybrid. If there is not, all power will flow through the energy storage/retrieval system, and that is called a series hybrid.

The energy storage/retrieval system could be electrical (motor-generator/battery), hydraulic pump-motor w/accumulator, flywheel storage w/electric drive, etc...

oh, yes- a fuel cell would be an engine, in this context, since it 'burns' fuel and it energy but can't store it.

so- what's important? overall power/weight
overall energy efficiency
overall cost efficiency
overall reliability
"overall" includes fuel/energy cycle, vehicle size/weight/cost/performance...

so, a Prius (or Civic, or Insight, or Escape, etc.) could have a small turbo-diesel, and have the hybrid gains and benefits on top of the basic fuel thriftiness of the diesel. Toyota had enough to worry about, without getting US customers to accept a Diesel-powered wierd car!

My impression is: Hydraulic tends to be big, heavy, expensive, inefficient. Obviously that's not all true, since it is used in high performance aircraft.
But those cost cubic $$$$

cheers
Jay
Jay Maechtlen

 

[schwee]

Hi Jay --

I know little about hydraulics, but I think I agree with you. Maybe a good choice for heavy-duty "transmissions" on earth movers and other beefy items, but not suited to lightweight hybrids. "Lossy." Also, I don't see how the accumulator (yes?) could store nearly enough energy to serve as a buffer.

I don't like Priuses. They're really ugly, for one. I'm very impressed by their power-sharing drive system, but I do not get why they have a separate motor and generator. I get the sense that their batteries (typical of NiMHs) can't handle a very high current draw for very long before they heat up unacceptably. Certainly no more than 4 minutes, I think.

I like the Honda Civic Hybrid as the best choice for now -- non-ugly, non-outlandish, getting pretty darn good gas mileage and performance about comparable to a regular Civic. It's pulling back from the Insight and Prius, in that its ambition is really just to try to improve the efficiency of a regular car, in an affordable and reliable way. The notion of a small motor/ generator for smoothing the power drops between shifting, and adding a little to low end torque, seems smart, and combining the starter and alternator in the same package seems obvious -- why didn't we think of this before?

That's one path for innovation, and it seems worth following. In the meantime, though, what does one do with more radical innovations, if anything? To me, "radical" means series and composite bodies, for starters. It also means scrap the drive train and crankshaft -- if you're gonna commit to series, why load yourself down with these? Problem then becomes a viable, affordable energy storage. It's not batteries.

On this "other" path, it seems there's something of a razor's edge between aggressive, expensive experimental ventures and some sort of short-term viability. I, for instance, like carbon and boron nanotubes and nanowires a great deal, for flywheels and motors, but they're stratospherically expensive and not well understood. DC brushless motors are better understood, and in fact readily available, but they appear to be prohibitively expensive. Carbon fiber composites for body structures are fairly well understood and can be custom-ordered, but again they are quite expensive.

I guess I'd favor going perhaps 85% all-out. If DC brushless could conceivably brought into the realm of affordability in five or ten years, probably by finding cheaper and/or new types of permanent magnets, then go ahead and put the expensive motors in prototypes. If not, go after cheaper alternatives that are still higher performing than conventional motors -- I'm looking into "brushless synchonous reluctance motors" at present, whatever they are.

I think some technologies already have hit something of a "point of diminishing returns" -- fuel cells and batteries come to mind. Others, like nanotubes, are just too far off the radar screen. Ditto drive-by wire, which just strikes me as unfeasible (and stupid -- I LIKE driving, I don't want my car to do it for me). But others have just too high a potential to ignore. Carbon fiber bodies, for instance, are SO much lighter and stronger than steel and aluminum, that further research into, for instance, aluminum, seems a waste of talent and money. Ditto flywheels -- really, the ONLY promising technology for power buffers on the horizon, as ultracapacitors, hydraulics, compressed air, and batteries don't even have the long-range potential to make them worth pursuing for this application. True, flywheels, composites, and high power density motors all have significant hurdles -- but most are matters of cost and manufacturability, essentially, and those are much less insurmountable obstacles than, well, physics.

A final note is to continue to be aware of consumer tastes. The Insight didn't do as well as it probably should have because it LOOKS weird -- hence the "retreat" by Honda to the proven Civic. I read a review where the reviewer and his wife picked the Civic Hybrid over the Prius because, even though the Prius had better emissions, its interior was so quirky and wrong and non-standard that they just didn't feel comfortable (plus, did I mention it's godawful ugly?). And there's always the issue of performance -- the Prius, for instance, accelerates like a pig, though many reviewers and buyers are hesitant to say so.

My sister owns a Prius, and as soon as they bought it I said to myself "of COURSE they'd buy a Prius -- tree hugging, solar lawn mower-using, non-toilet-flushing geeks that they are. I wouldn't be caught dead with one." And I can't believe I'm alone. Pretty soon you've saturated the 15% of the populace that is truly environmentally committed -- enough to put up with an inferior car to help save the world -- and then you must make a car that can stand on its own merits. NO hydrogen, no natural gas -- only gasoline (preferably), diesel, and other liquid fuels that could be dispensed at your local gas station -- alcohol and methanol, perhaps.

--paul

 

[EdDanzer]

Schwee,
Your knowledge of hydraulics is very limited. The highest energy storage densities for motors or actuators is hydraulics. For an example go to a rental yard and look at the small excavators. This web site will allow you to look at compare models, the smallest weigh 1800 to 2400 lbs and have 8 to 10 hp.

http://www.constructionequipment.com/specguidenew/spec2.asp?Type=Mini Excavator

Try designing one with electrics that has the same forces and see what it would weigh. The track drive in electrics would weigh and cost 3 to 5 times as much for the same output torque with less reliability.
As to accumulator storage, I have been trying to understand battery ratings when being discharged, how many amps can be drawn before the voltage drops below a certain level so battery energy storage could be compared to energy stored in an accumulator. With hydraulics, pressure is similar to volts and flow is similar to amps.

 

[schwee]

EdDanzer --
Told you I didn't know much about hydraulics. This Insight/ Prius comparison might give you some useful info on discharge rates, if you haven't seen it:

http://www.afdc.doe.gov/pdfs/bat_thermal.pdf

--Paul

 

[EdDanzer]

schwee
Now I will to show how little I know about electrical stuff.

When I look at the information about the Insight/Prius stuff I can’t figure out just how much energy was used during discharge and what the rate of discharge was. If anyone could put that information in simple terms it would be helpful.

Ed

 

[GregLocock]

Interesting paper, but there is a lot of data missing.

The crucial info for your purposes is probably in table 11.

If you look at FTP 75 for the Prius it saying that over the 11.1 mile cycle 2468 kJ went from the battery to drive the car, 531 kJ went from the battery into the auxiliaries, and the battery was recharged by 3232 kJ. Fuel energy used was 25200 kJ.

http://www.dieselnet.com/standards/cycles/ftp75.html

details the test cycle. The test takes 1874 seconds, giving an average speed of 21 mph, so it should highlight the benefits of a hybrid system.

Dividing the energy useage by the time in the test I get the following

Bat->Traction Bat->Aux Recharge Engine
KJ 2468 531 3232 25200
W 1316.97 283.35 1724.65 13447.17
Hp 1.77 0.38 2.31 18.03

I emphasise, these are averaged over the half hour cycle.



Cheers

Greg Locock

 

[schwee]

Back to the idea of "hot" hybrids --

I just re-found these. Opel Eco Speedster -- 112 hp, 1.3 liter turbo diesel, 1455 lbs, 155 mph, Cd 2.0. 112 mpg combined. So they say. And it's not a hybrid, actually -- just light and with a fuel efficient engine. And really HOT looking, I think.

http://www.carkeys.co.uk/features/FE000450.htm

video button:

http://www.gm.com/company/gm_exp_live/events/paris_2002/opel/ecospeedster/

 

[GregLocock]

Oh, here is the speed time profile for FTP 75. (Don't ask).

http://members.optusnet.com.au/greglocock/ftp75.txt

There is also a 10 minute heat soak with the engine off in there, at 1380 seconds.

I'll put together a spreadsheet that will give a predicted energy consumption for a given vehicle, beats watching the idiot box. It won't account for warmup effects.



Cheers

Greg Locock

 

[schwee]

Here's a news item about truly stupefying mileages (from Rocky Mountain Institute -- usually means take with a grain of salt) --

12/00: Volkswagen plans to create a prototype of a diesel-powered, two-seat car that garners 282.5 miles per gallon before the end of 2002. The new offering would use only one liter of diesel fuel for every 100 kilometers (62 miles) traveled, and a single-cylinder, 1.0-liter diesel engine would power the vehicle. To comply with strict European safety regulations, it would be built with protective crash structures but would only weigh 1,000 pounds. Volkswagen did not indicate exactly when the car will appear or whether it will be offered to the public.

 

[schwee]

Food for thought:

Acura DN-X -- IS a hybrid -- 300 hp gasoline plus 100 hp electric. 400 hp, claims "up to" 42 mpg. That's just sorta sick. Could probably be made to look like the more handsome NSX.

http://cars.ign.com/articles/384/384725p1.html?fromint=1&submit.x=67&submit.y=11

--Paul