Automobile Environmentalism: Hybrid vs. Combustion

[SickBeast]

The way I see it, energy is energy. It cannot be created nor destroyed. Therefore, by simply driving anything, we are damaging the environment. The greater the mass of the vehicle, the greater the damage.

The one thing that the hybrid has going for it is the elimination of emissions at idle, which is a great thing for urban air quality.

The con to the hybrid is the hazardous production and disposal of the batteries (and perhaps their explosion à la Sony!).

I suppose option #3 is some kind of chemically engineered fuel that is incredibly clean burning and can run in current combusion engines. I've heard something about Canola, but perhaps someone here will have further insight.

So which is better? There is a tax rebate on the hybrid...I would assume then that research has somehow predicted them to be superior overall. How long are the batteries predicted to last? How many charge cycles are they good for? Can they indeed catch fire and blow up the car in the event of a collision?

Cheers. :beer:

 

[Genx87]

If there is a subsidy for a technology, it doesnt necessarily mean it is the best, just whoever is benefitting by selling or using the technology managed to con\bribe the politicians into writing the law to subsidize that technology. A fine example of this is E85, subsidized to the hilt and provides less mileage compared to gasoline and requires the burning of fossil fuels to make it.

I dont have all the answers and I think when we run out of oil we are in for a rude awakening. All the other alterntives sound like they will take a lot of energy to produce. Fossil fuels are so cheap and easy to get, I fear what will happen when they are used up.

I honestly believe for a long term solution we are going to have to somehow harness energy from the glowing ball in the sky, whether it is creating out a sun on earth or solar panels. We need a cheap high energy source to replace the current crop.

 

[gsellis]

Actually Sickbeast, it is not so much the off at idle that makes a hybrid efficient as regenerative braking. If a hybrid has regenerative braking, it can conserve and store any of the momentum it previously had. It can then used that "saved" energy to help get back up to speed. Otherwise it is just wasted heating the brake pads and rotors.

And I read this in Autoweek in the 80's and it is still true to this day. "There are liars, damn liars, and battery engineers." The disposal of the batteries is part of it. But because the batteries deteriorate over use, they have to be replaced. If you hold onto a hybrid for 100k miles, you will probably have to replace the battery packs. That will set you back about $3-7k. That is a hidden cost that makes hybrids more expensive and much less valuable (no resale value when folks figure this one out.) When it starts dawning on folks, hybrids may lose their luster. Early fuel cells may run into the same "reliability" issues.

 

[CSMR]

I imagine the rebate is designed to encourage technological development rather than for present environmental benefits.

 

[CycloWizard]

Originally posted by: SickBeast
The way I see it, energy is energy. It cannot be created nor destroyed. Therefore, by simply driving anything, we are damaging the environment. The greater the mass of the vehicle, the greater the damage.

The mass is not the only factor dictating environmental damage. Assuming that one can equate environmental damage with the amount of gas used, engine size and efficiency are very important factors.

The one thing that the hybrid has going for it is the elimination of emissions at idle, which is a great thing for urban air quality.

Hybrids increase the amount of power generated by a unit of gasoline. Thus, the net environmental damage is decreased (at least during in-city driving).

I suppose option #3 is some kind of chemically engineered fuel that is incredibly clean burning and can run in current combusion engines. I've heard something about Canola, but perhaps someone here will have further insight.

Any type of combustion reaction will release H2O, CO2, NOx, CO, and all of these other environmentally harmful compounds. With a perfect engine and catalytic converter, it could be that we release only CO2 and H2O. Changing the fuel might help us towards this ideal condition, but these two products are the primary gases implicated in global warming at this time, so I'm not sure that would help anything. The amount of energy that is generated is a direct result of how much CO2 and H2O are produced. It is true that the fuel compound will have some effect on the ratio of energy output to CO2/H2O emissions, but fuels that would give significant improvement in this area are usually avoided for safety reasons (e.g. pure methanol/ethanol).

 

[imported_inspire]

I've actually been interested in this for awhile.

@sickbeast - aside from better planning, a change in culture, or severe economic constraints, most folks will still have long commutes and still drive big cars. One thing we can do is reduce emissions. I don't really know much about battery disposal and its environmental impact. I do know that the Ethanol Blend E85 produces a tenth of the NOx emissions of Gasoline. There are still a lot of unknowns concerning E85, though, such as the net energy of producing and using E85 (the effort spent farming the corn and refining the Ethanol), the total economic impact (how it would affect Corn Farmers, and as a result, the food industry), etc.

The main advantage, in my opinion, in terms of efficiency for a hybrid is this. Because of how ICEs are engineere, they have a powerband. This means that your engine is most efficient at a certain range of RPMs. The advantage of Hybrid cars is that they can use that powerband all the time. This is good because on some vehicles you may not hit the power band until you get to 4000 RPM (highway driving). So, by letting the engine generate electricity and then converting the electricity into motion, you run more efficiently. This works because electric motors don't have a 'powerband' per se. Electric motors deliver a constant amount of power regardless of the RPM.

As for batteries, I'm not sure, but I found this - you may be interested.

@Genx87 - Right now, E85 has to be subsidized to get anywhere. Once it mainstreams, farmers will have to be paid subsidies to produce corn for food rather than Ethanol, since Ethanol will be more profitable - well, that's what some folks are thinking, at least. but, you're right, at this point, E85 isn't the best thing out there (but that could change).

Yes, E85 is less mpg than gasoline simply because E85 has less BTUs per gallon than Gasoline. Keep in mind that although we are seing the first Flex-Fuel vehicles, none of these engines are specifically optimized for E85. The technology is new and should get better once it has more time to develop. The model T didn't get 30 mpg.

The rude awakening may come sooner than you guys think. With the demand for oil steadily increasing worldwide and global production expected to peak between 2010 and 2020, price will jump as demand exceeds supply. What I mean is that once production hits a flat rate and demand surpasses it, prices will go up to compensate. There is an excellent book by Dr. David Goodstein of CalTech that explains this a lot better than I can - 'Out of gas' is the title.

@gsellis - Last I heard, Regenerative Braking added a max efficiency boost of 10% - is that still the ceiling?

 

[gsellis]

Originally posted by: inspire
I've actually been interested in this for awhile.

@sickbeast - Electric motors deliver a constant amount of power regardless of the RPM.

There is something wrong with how you are saying that. HP is a function of RPM, so that statement can't be what you meant to say, right?

@Genx87 -
The rude awakening may come sooner than you guys think. With the demand for oil steadily increasing worldwide and global production expected to peak between 2010 and 2020, price will jump as demand exceeds supply. What I mean is that once production hits a flat rate and demand surpasses it, prices will go up to compensate. There is an excellent book by Dr. David Goodstein of CalTech that explains this a lot better than I can - 'Out of gas' is the title.

Only problem with this is it ignores other factors. There are other sources that are not worth investigating because of variable price of oil. If the price of oil would stay at a fixed rate such as $60/barrel, it would then be worth it to commit resources to developing alternate sources. But, OPEC knows this too. I personnally know someone who was burned by this the last time oil had a big jump (in the early 80's). Invested heavily in retrieving expensive oil (4 mile holes). Then OPEC jumped the supply up and it nearly killed his company.

@gsellis - Last I heard, Regenerative Braking added a max efficiency boost of 10% - is that still the ceiling?

Not sure on the ceiling, but 10% on a highly efficient system is a bunch. Efficient systems are diminishing returns as you go higher. So, if you are maxing what you can do with technology on engine and aero packages, adding 10% more is great. I thought it was higher, but I have not been tracking it. Once I figured out the battery thing, I lost all interest in current gen. hybrids.

 

[kpb]

Internal combustion engines are most efficient in a power band but I don't think most current hybrids take advantage of this. What your describing where the engine just generates electricity and the electric motor actually moves the car is a serial hybrid. Current hybrids, especially things like the civic hybrid etc that are just hybrid versions of exsisting cars use a parallel hybrid setup where both the gas engine and the electric motor are hooked up to the transmition which can be driven with one or the other or both depending on needs. Even the Prius uses a parallel design but it does have some fancy tricks to help keep the gas engine in the power band more of the time. http://auto.howstuffworks.com/hybrid-car.htm has pretty good explaination of most of it.

Current electric hybrids are probably going to be getting bad press in a few years when, as other people pointed out, batteries are going to start failing and people will be stuck with several thousand dollar bills for replacement batteries and disposal of hazardous waste. Hydrolic hybrids look more interesting IMO. Hydrolics are fairly well understood and maintainable and should be lighter and more compact for the amount of energy they can store. http://www.popsci.com/popsci/automotive...6b64fc010vgnvcm1000004eecbccdrcrd.html is an interesting article about high mpg ideas and talks about the hydrolic hybrid.

I've heard of some other interesting things to increase MPG in cars. Replacing wiring with an inteligent bus instead of the centralized brain with a bunch of dumb sensors. The large amount of wiring in a car actually accounts for a notciable amount of weight. Better insulation/ventilation to reduce the amount of energy used cooling the car. Pretty much anything that uses energy or wastes it as heat is potential for improved efficiency.


As for e85 it can be made more efficient with design improvements over current flex fuel vehicles. Our current vehicles are basically exsisting vehicles with different fuel lines to handle the e85 since it's more corrosive. It is how ever higher octane and could be run at higher compression in the engine but that would require either a design that can vary compression or using premium gas when running on regular gas. Additionally corn is a rather poor way of generating ethanol for e85 fuel. It's the primary way of making it in the states primarily because of political subsities tied into grain subsities and levies on sugar cane. Brazil currently has a very viable e85 system using sugar cane but that doesn't grow well in the states. Unfortunately high levies to protect our local corn based ethanol production make it impractical to import brazils cheap e85. Currently the best looking option in the states is actually switchgrass which grows quite easily and generates more ethanol for less effort per pound harvested. http://petroleum.berkeley.edu/papers/Biofuels/NRRethanol.2005.pdf has good information but is a research paper so a bit dry =) http://www.wired.com/news/planet/0,2782,67691,00.html is a better read but not as detailed.

 

[imported_inspire]

@gsellis - Oh, I didn't realize that... (3 or more years since the last physics class), but what I'm driving at is that motors don't suffer from the constraints of a powerband like engines do.

By other factors, you mean political? The book talks about simulation studies using past oil exploration / production and demand figures. Sure there are lots of discrete variables being modeled, but they most likely are implied in the model - it's been a few years since I read it.

As for batteries, I guess that's less of a deterrent for folks who lease or buy a new car after they hit 75k. But for those of us who aren't cumplsive consumers, Hybrids make less sense.

EDIT: @kpb - nice information! How come series hybrids aren't made, though?

 

[kpb]

Originally posted by: inspireEDIT: @kpb - nice information! How come series hybrids aren't made, though?

I haven't read anything specific about why serial hybrids aren't made but I can take a few guesses. For most hybrids that are based on exsisting car designs like the civic hybrid etc, it's a much simpler process to make a parallel hybrid where a serial hybrid would require major changes. Even strictly hybrid cars like the prius and insight probably stick parallel in design because it's much closer to current design and much better understood by thier designers. Any major changes or things very different take a while to catch on.

One area where serial hybrids are actually very common is heavy equipement. Most heavy equipement is a serial hybrid using a desiel generator to run electric motors because they generate so much power for things like train engines, big construction equipement, etc that transmisions just couldn't handle it.

 

[kpb]

As far as hydrogen goes, since I'm sure someone will bring it up, hydrogen is not a source of energy. It's a way of storing energy like a battery. You might be able to to improve efficiencies and emisions somewhat over the internal combustion engine using standard gas but for it to really be viable we need to transition our power generation off of fossil fuels since currently most of our power generation comes from coal or natural gas generators. Current stats show coal generating about half our power http://www.eia.doe.gov/cneaf/electricity/epm/table1_1.html . If we can establish viable alternatives of clean energy and power our grid from those exclusively and have spare capacity or at least the potential to generate more then hydrogen becomes more viable. Currently Iceland produces a substantial amount of it's electricity from geothermal and is looking to use that to start making heavy use of hydrogen and very well may be the first country to be "free" of fossil fuels.

There are alot of different potential renewable resources that could be tapped in the states to allow us to do the same but currently they are unproven and not competative with fossil fuel generated electricity. Wind power in the central planes and off the coasts. Areas of geothermal power in the states. Hydro electric. Even switch grass and other prolific crops can even be burned for fuel.

 

[gsellis]

Best hybrid I ever saw was made in the 70's by U of Michigan? Used a hydralic system with a 16hp Briggs and Stratton. It would sustain 60mph and 0-60 in 8sec. Was featured in Mother Earth News with a Bradley GT body. The hydralic system powered it and the B&S charged the system. Regenerative braking on the system. Space sucked though because of the large accumulators. Also, high pressure hydralics can be an issue. (and I swear my spelling of hydralic looks totally wrong - I am sure I will be corrected )

 

[Pulsar]

Serial hybrids are LESS efficient that parallel.

You lose energy when you change it's form from fossil fuel into electricity to power the motors, rather than using it directly.

The major savings in hybrids come from regenerative braking where some of the energy is stored and used, AND the ability to "shut off" the engine.

Most of the rest of the hybrid's savings when looking at a car like the Prius are aerodynamics, weight, and smaller engine = poor performance. The mileage numbers that you see on the windows of the cars at the dealership are wrong for hybrids - the current mileage tests simply can't account for a car that turns it's engine off when it should be idling. Changing the test, however, would invalidate years of data... so they don't want to change it.

In reality, we already had 60 mile to the gallon cars that are a similar size the prius. They cost a whole lot less to build as well.

Hybrids are a neat idea for CITY drivers, but they are currently no better (and in fact in some ways, like the disposal issue with the batteries) and in some cases worse for the environment than high-efficiency cars that are already out there if you do a lot of general purpose driving including freeways.

 

[Geniere]

Originally posted by: Genx87? and I think when we run out of oil we are in for a rude awakening. All the other alterntives sound like they will take a lot of energy to produce...I fear what will happen when they are used up?

Needless worry!

?A settler in Parachute Creek, Colorado built a log cabin using the local black rock to make the fireplace and chimney . He invited a few neighbors to a house warming and lit a fire. The fireplace, chimney, and ultimately the whole cabin caught fire and burned to the ground. The rock was oil shale. It was a sensational house warming!? - - -Source for quote

There is NO shortage of oil; the US alone has more than a 200-year supply at the present usage rate; more than 2 trillion barrels in Wyoming, Colorado and Utah; more oil than any other country in the entire world. It?s a little more costly to produce but if the market price per barrel of crude stays above $35.00 it?s a go.

? The federal government has taken a step toward approving the reopening of an oil-shale mine in Utah, one of four experimental works on Western lands that are intended to boost domestic oil production?In Colorado, three oil companies won environmental clearance in August for their plans to start producing shale oil by heating layers of rock using electric oven-like elements, steam injection or hot natural gas?.?Source for quote

...

[/quote]

 

[BrownTown]

Actually, its alot mroe costly, but the point is still valid so long as oil prices keep climbing. Personally I want to get off using oil for fuel because of the other huge use of oil which is the checmial industry. All the plastics we use and alot of the organic chemicals are based off oil, and if we burn it all up we arent gonna be able to have everything made of plastic anymore.

 

[Qriz]

The point of hybrid cars isn't that it saves energy, because yes, the electricity in the batteries came from fossil fuels as well. It's mostly the reduced emissions, and the regenerative braking is great too (and it sounds pretty sweet, if you've heard it before.) Also, the computers that control weather a hybrid uses the electric or gas motor are meant to maximize efficiency and minimize emissions, depending on the conditions (speeds, highway or city, etc.) You can't do that with a combustion car, which only has one option: pump that fuel!

Hybrids cost quite a bit (my Highlander was $40,000.) You won't save that difference between the price of a non-hybrid during its lifetime. Even the dealer pointed that out. Basically, you're paying that much more for the battery, which is meant to last most of the car's lifetime. But we don't know if that'll happen yet, do we?

Combustion engines are running out of fuel, so to speak (Geniere, read this and it's obvious that in the next 50 years there is going to have to be an ENOURMOUS switch of energy sources. We're talking worldwide, though the US may last longer than other counties (it already is.)

 

[CycloWizard]

Originally posted by: Qriz
The point of hybrid cars isn't that it saves energy, because yes, the electricity in the batteries came from fossil fuels as well. It's mostly the reduced emissions, and the regenerative braking is great too (and it sounds pretty sweet, if you've heard it before.) Also, the computers that control weather a hybrid uses the electric or gas motor are meant to maximize efficiency and minimize emissions, depending on the conditions (speeds, highway or city, etc.) You can't do that with a combustion car, which only has one option: pump that fuel!

The point of hybrid cars is very much to save energy. By recovering some of the energy that would otherwise be lost as friction, the net efficiency of the car is improved. If the batteries were charged using a wall outlet (which I don't believe they can be), then the net efficiency would still be improved, as electricity production at power plants occurs at large scales and higher efficiencies than in an automobile engine. Any time emissions are reduced, efficiency must also go up as the two are causally related.

Hybrids cost quite a bit (my Highlander was $40,000.) You won't save that difference between the price of a non-hybrid during its lifetime. Even the dealer pointed that out. Basically, you're paying that much more for the battery, which is meant to last most of the car's lifetime. But we don't know if that'll happen yet, do we?

There are numerous recent studies (here's one) that would beg to differ with your conclusions. It even lists the Highlander as one that will eventually pay the difference between the hybrid and non-hybrid, though its payback period is relatively long.

 

[BrownTown]

Originally posted by: CycloWizard

Originally posted by: Qriz
The point of hybrid cars isn't that it saves energy, because yes, the electricity in the batteries came from fossil fuels as well. It's mostly the reduced emissions, and the regenerative braking is great too (and it sounds pretty sweet, if you've heard it before.) Also, the computers that control weather a hybrid uses the electric or gas motor are meant to maximize efficiency and minimize emissions, depending on the conditions (speeds, highway or city, etc.) You can't do that with a combustion car, which only has one option: pump that fuel!

yes, CycloWizard is right, the entire point of a hybrid car is to increase energy efficiency and therefore save energy so you need less gas. However, even with hybrid technology cars are still terribly inefficient when it comes to using the energy in gasoline, give me a sec and ill find some good graphs to show that.

 

[darkhorror]

What would happen if we used the heat energy, and exaust energy from the engine to charge a hybrid battery?

 

[PowerEngineer]

Ack! You guys are making me feel bad about my Camry hybrid!

It's a bit tricky to determine (given the differences in baseline equipment between Camry trim levels), but I estimate that the hybrid MSRP was about $3k higher than a comparibly equiped LE. On the plus side there a federal tax credit for buying the hybrid (was $2600 through yesterday), but the dealers hold out for much closer to MSRP on the minus side.

I'm usually seeing 35-40 mpg on most trips, which is about 10 mpg greater than what I would have expected from a Camry 4-cylander. I'm thinking that I should break even on reduced fuel costs in about four years (~60,000 miles).

The batteries are guaranteed for 100,000 miles, which I take as a good sign most will last much longer (I'm betting on 150,000 miles). The cost of replacement and disposal wasn't someting that I had given any thought to. I'm thinking to sell this car in about six years anyway (during a spike in gas prices).

 

[Geniere]

Originally posted by: BrownTown?Actually, its alot mroe costly, but the point is still valid so long as oil prices keep climbing?

Actually the $35.00 figure is quite a good estimate but the Israelis, sitting on an abundance of high quality shale, are looking to produce at about $20.00 per barrel.

Originally posted by: BrownTown?Personally I want to get off using oil for fuel because of the other huge use of oil which is the checmial?.

Agreed, however there are always alternative methods. Economics is the key to production methodology, not a perceived scarcity of resources.

Originally posted by: Qriz? Combustion engines are running out of fuel, so to speak (Geniere, read this?

Once again, there is no shortage of oil and Brazilian cars run just fine on grain alcohol! The very fact that burning hydrocarbons pollutes our atmosphere is sufficient reason to stop burning them. It is a compelling argument, so compelling that it needs no augmentation. Reasonable people will draw reasonable conclusions and produce reasonable solutions. There is no need for the specious shortage argument.

Originally posted by: Qriz?yes, CycloWizard is right, the entire point of a hybrid car is to increase energy efficiency and therefore save energy so you need less gas. However, even with hybrid technology cars are still terribly inefficient when it comes to using the energy in gasoline, give me a sec and ill find some good graphs to show that.

I believe the hybrid vehicle is a sensible purchase and will remain so for the next decade or two. It is, however, dead end technology as it can only diminish noxious emissions, not eliminate them. A stored energy vehicle is the ultimate choice whether all electric or hydrogen burning. I?ve seen no battery developments that would suggest a battery-powered car would be of use except as a short distance commuter. That leaves only the hydrogen fuel cell to power the vehicle of the future.

Of course the Hydrogen must be produced via clean technology, fusion, fission, wind and tides?

 

[Geniere]

Originally posted by: PowerEngineer?I'm usually seeing 35-40 mpg on most trips, which is about 10 mpg greater than what I would have expected from a Camry 4-cylander?

But part of the fun of driving a hybrid is to watch the gauges and try to extract the most energy from every last drop of fuel.

Originally posted by: PowerEngineer?I'm thinking to sell this car in about six years anyway (during a spike in gas prices)?

My dealer friend says sell about 2 yrs before battery warranty is up.

 

[Calin]

Originally posted by: SickBeast

I suppose option #3 is some kind of chemically engineered fuel that is incredibly clean burning and can run in current combusion engines. I've heard something about Canola, but perhaps someone here will have further insight.

Cheers. :beer:

Option #3 would be to use ethanol (alcohol) for gasoline cars and edible oils for diesels (methanol, which is a simpler alcohol, is used in some competition cars). However, I vote against methanol as it is dangerous (can cause blindness) and it will evaporate quickly in air).
The diesel engines needs only updated fuel tank/pump/distribution assemblies (sunflower oil at 85degrees C is just as fluid as diesel fuel at normal temperature, so you need to heat everything).
The jazzoline engines needs more changes to use ethanol, as ethanol doesn't give even the little lubrification the gasoline allows. There are other changes too, but it is possible.

What oils could you use? I suppose any kind - corn-derived, canola, sunflower, even olive oil (though it is much more expensive).

 

[Calin]

Originally posted by: inspire
One thing we can do is reduce emissions. I don't really know much about battery disposal and its environmental impact. I do know that the Ethanol Blend E85 produces a tenth of the NOx emissions of Gasoline.
...
Yes, E85 is less mpg than gasoline simply because E85 has less BTUs per gallon than Gasoline.

The Nitrogen oxides - NO, NO2 and NO3, generally named NOx, are created only at high temperatures. Diesel engines are prone to the creation of those oxides as the diesel engine reach a higher operating temperature (inside cylinders).
However, the higher the temperature an engine has in its cylinders, the higher the efficiency of its thermodynamic cycle. You get back more work from the same energy (heat) input.
So, the reason for the increased mpg from LPG/E85/gasoline/diesel isn't only in energy density per volume (energy per gallon) but in engine efficiency. Reduced NOx creation seems to imply a lower temperature, and a lower thermal efficiency.

 

[Calin]

Originally posted by: gsellis

Originally posted by: inspire
I've actually been interested in this for awhile.

@sickbeast - Electric motors deliver a constant amount of power regardless of the RPM.

There is something wrong with how you are saying that. HP is a function of RPM, so that statement can't be what you meant to say, right?

No, he said it just right. Most electric motors (non-synchronous motors) have a huge torque at low RPM, and their torque decreases as they reach their operating rpm (at operating rpm they have zero torque, higher than operating rpm they have negative torque). The operating rpm is equal to the number of poles multiplied by the frequency of the alternative current they are fed with.
DC motors have a similar torque characteristic.