Green Cars

[chuck kottke]

Well, it's an issue alright - I'm not happy with the way we're approaching biofuels as well, but say for instance we used switchgrass for cellulosic ethanol, and it were done efficiently. To me, that's legit. But it has to be done in concert with large improvements in efficiency, or it hardly makes a dent in the problem...

Have you ever smelled the exhaust of a Diesel running on bio-diesel? It smells like frying donuts!:P

Plus, one has to consider what we do with our massive grain crops - much of it goes to feed livestock, which is a very inefficient use to begin with. Besides, cows are meant to eat grass and other herbs, not grain.. Oh well, that's another topic!

Ah, but you can power an SUV with the same engine as a smaller car, Katie! How so? Well, it turns out that most of the time, you only need 10-20 HP to keep an auto going down the road at highway speeds. The horsepower is only really needed when you acclererate or climb a hill. Therefore, an SUV with a small engine and a battery/capacitor boost system works just fine! And the more aerodyamic the auto, the less power is required to push through the air at highway speed.

Since sports cars are using that same energy for acceleration and top speed, it's actually quite do-able. The secret rests with drag coefficient, cross-sectional area, and weight.

Cars and airplanes are really quite similar in many ways, and one historic example is the Japanese Zero. The plane was built with very light, strong aluminum alloys, and a light, powerful engine. It could mauver like a kite, turn on a dime, and accelerate like a bullet! The same concept today, applied to autos as composite bodies, aluminum monoques, and exceptional streamline designs has the same effect in the automotive world.

Yes, you're right on the money there! Weight is one issue, both for acceleration and for rolling friction. Lighter cars are fast on takeoff, and traction issues can be overcome with newer tire designs, and rear ailerons. And new materials are the way - they offer exceptional strength at a minimum of weight, and can offer excellent crash protection as well.

[a_face_of_light]

what do you think is an acceptable amount of power for a car of each class to produce, and what do you think weight should be reduced to, I'm all for greater efficency but am curious as to how you think it should be done.

 

And whats wrong with the electric Range Rover?, apart from them being a little optimistic in the recharge in 10 minutes stakes:P

[chuck kottke]

what do you think is an acceptable amount of power for a car of each class to produce, and what do you think weight should be reduced to, I'm all for greater efficency but am curious as to how you think it should be done.

An 'E class' Mercedes should produce 320 Horsepower..:laugh3:

From an engineering perspective, I feel it's more important to design a given automobile for the use intended by the customer; So, if one has, for example, a car intended for a family or large group of persons, the cross-sectional area will naturally be larger, and so will the weight compared to a mid-sized automobile. And since cross-sectional area is a proportional component of overall drag, then a corresponding increase in horsepower must be factored in. Specifics I cannot offer, but in a general sense:

> Drag coefficient should be below .20, and preferably below .10 This proves to be more than double the current drag coefficient for most SUV's and light trucks (.36 is a common value today).

> Weight should be reduced by 50%, a figure which is readily achievable using bio-composites, aluminum alloys, honeycomb materials, and the like.

> True Hybrid Designs implemented, offering high torque electric motors to be coupled with both carbon nanotube capacitors and lithium bateries, allowing for very fast response when acceleration is needed; rapid power from capacitors for quick acceleration, and lithium batteries for continuous power.

> Finally, the engine required needs to recharge the batteries and caps, and power the vehicle at highway speeds with a headwind up a long hill. To do that, 100 horsepower seems like a maximum (this is actually more horsepower than the Dymaxion car had in 1933, and it was tested at 90 MPH; 120 was design top speed.)

> Advertisers need to correct a long standing misconception that horsepower translates to performance; They need to stress acceleration, handling, fuel economy, range for all-electric mode, and comfort of ride.

>Safety amazingly can be equal to heavier vehicles with better designs for impact crumpling, and systems to warn of cross-traffic, perhaps with computer auto-braking systems need to be added.

> I would push for solar panels to be added to the vehicle's outer skin. They haven't much output (maybe 1/2 Horsepower continuous), but over a day baking in the sun & charging batteries, can extend the range of the vehicle by 1/3 or more.

And whats wrong with the electric Range Rover?, apart from them being a little optimistic in the recharge in 10 minutes stakes:P

I like Rangerovers too, Katie.:) They're great for slow, muddy roads in places where "improved" roads means they put bridges over the streams, and gravel on the gooey clay hills. But, the body shape (a traditional shape for trucks from a bye-gone era) is boxy and un-aerodynamic. Fine at 20 MPH, but wasteful at 60 MPH. And the weight - there's no problem today to make vehicles lighter, so the weight needs to be halved, and the strength actually increased. The clearance is fantastic for rutted roads, and that doesn't significantly increase drag, but the underbelly needs a smooth pan to elimiate drag (and brush that gets caught in the suspension members!:P).

 

One factor holding this all up is the auto makers. They would have to change production methods quite a bit, and the cost to retool would cut into their profit margins for a few quarters.

Another factor is vehicle appearance. These retooled vehicles would look different, and their acceptance would take quite some time (unless gas prices soar again!).

So, since rising fuel costs cause angst with the public, the only real way to get the change to happen before an oil shortage is through government incentives to consumers, offsetting the purchase cost for a super-efficient vehicle. Also, mandated standards can help too - really upping the CAFE standards and safety standards, for instance.

[chuck kottke]

Here's a nice summary of the matter of vehicle energy consumption:Energy Losses in a Vehicle

Engine Related: 79.6%

Engine Losses - 62.4%

Idling - 17.2%

Vehicle Related: 20.4%

Accessories - 2.2%

Driveline - 5.6%

Aerodynamics - 2.6%

Rolling - 4.2%

Braking - 5.8%

 

But this is an average, and the truth is much more nuanced. Gasoline engines peak around 25-30% efficiency; Diesels peak around 30-40% efficiency. Diesels are better because of their higher compression ratios.

Idling is a problem with in-town driving, so varies depending on where you live. True hybrid designs use the engine as a generator set mainly, so idling losses disappear with true hybrids.

**Note: Battery electrics save because of their basic efficiency, but one has to consider the power to produce the electricity at its source. A good path to take, if the electric is from solar, wind, or geothermal.

Accessories use more that I thought! Air conditioning is probably the elephant in the room, so here we can improve by better vehicle insulation, brighter, more reflective paint finishes, self-tinting or variable reflective coatings in auto windows, etc.

Driveline is a matter of engineering changes. Continuous variable transmissions help, as well as constant torque motors.

Aerodynamics is more significant than in this estimate I believe, and is highly dependent on where you live. Long highway commutes double or triple this factor, but city driving halves it. It is the one variable over which we have the most to gain through changes.

Rolling friction is where the rubber meets the road. Small changes as possible with tire design, but much larger changes are possible with lighter vehicles, as a lot of the heat of tires is generated by the constant flexing of the rubber. Look for more improvement than what the article states.

Braking Also dependent on where you live. Very significant in city and suburbs, not so significant in rural and highway driving. Regenerative braking can significantly reduce losses here, and given the energy poured into just heating bake pads, this is well worth the engineering effort.

 

On the Production end, engines can benefit from the following improvements:

1. Use the highest compression ratio possible at current engineering levels. Higher compression brings the engine closer to ideal engine efficiency (Carnot's ideal gas law engine). Hence Diesels are 10% better than gasoline engines.

2. Allow for engine designs which take full advantage of the hot gas expansion. There's no reason for exhaust valves to get so hot, or manifolds - this happens because the hot gasses are ported before they can put full effort into moving the piston. So either more piston travel is needed, or exhaust turbines installed.

3. Use heat-reflective liners in cylinders, to prevent heat losses on the "hot" side of the engine.

4. Lower component friction whenever possible.

5. Employ full hybrid design so idling becomes unnecessary.

 

On the Consumption End, things stack up as follow

Accessories - 11%

Driveline - 27%

Aerodynamics - 13%

Rolling Friction - 21%

Braking - 28%

 

Here, the answers show where insulation and heat-reflective interiors help, as well as coatings in windows to variably reflect light will save quite a lot in vehicle cooling loads. Better drivelines are essential, aerodynamics is the easiest to gain savings in, and rolling friction means a need for vehicle weight loss. Braking is significant, and regenerative brakes make oddles of sense. Of course, this is for California drivers, so elsewhere, if you drive sensibly, you'll only loose a 5th of the energy to braking. ;-)

 

[a_face_of_light]

After the amount of expeirence that Manufacturers have in building cars I can't help but think there are ways of improving the efficiency of current engines, in my opinion a gasoline powered car should be able to achive about 30-40 miles per gallon and a diesel between 40-60 miles per gallon depending on the size.

I don't know the greatest deal about cars but checking up 320 horsepower isn't a huge amount anymore, but some cars have huge engines to produce the power when some are alot smaller, look at performance motorcycle engines for example thier 1000cc and produce 170 or 180 Horsepower ish, why does a car need 2000cc-3000cc to make the same amount of power?.

[chuck kottke]

After the amount of expeirence that Manufacturers have in building cars I can't help but think there are ways of improving the efficiency of current engines, in my opinion a gasoline powered car should be able to achive about 30-40 miles per gallon and a diesel between 40-60 miles per gallon depending on the size.

I don't know the greatest deal about cars but checking up 320 horsepower isn't a huge amount anymore, but some cars have huge engines to produce the power when some are alot smaller, look at performance motorcycle engines for example thier 1000cc and produce 170 or 180 Horsepower ish, why does a car need 2000cc-3000cc to make the same amount of power?.

Well, at least 60 miles per gallon gas, 90 miles per gallon Diesel, Katie!

It's the redesigns they don't want to do - they stick with standard blocks, and only tweak around the edges.. basically, they're dragging their feet. We'll need to see 80-120 MPG to gradually slow the man-made portion of climate change significantly, and the acidification of the oceans, etc. I wonder sometimes if we'll get there.:\

320 Horses is basically a joke of sorts. 320 isn't what's important -what is is acceleration and response. But the old ways die hard! What's needed isn't horsepower, but instantaneous high torque, and the electric motors can deliver that. It's like the steam engine days transitioning to Diesel-electrics - the steamers looked and sounded powerful, but we in fact not as powerful, and were very wasteful of fuel.

Well, a smaller engine can produce a great deal of horsepower if it runs faster, , has forced air injection, or has a higher compression ratio. But if it's pushed too hard, it might blow up!:laugh3: Probably the motorcycle engine spins real fast I'm guessing. But if you want to get up to speed fast, the same can be accomplished with capacitors, batteries, motors, and some recharging..

Horsepower isn't really the answer (unless you need an engine for a bulldozer.) - the biggest factors for acceleration are instantaneous power and mass; the big bulky engine which can produce 320 horses spends the rest of the ride mostly as automotive dead weight..

Aptera's showroom look:APTERA_2009_2E_BROCHURE.pdf (application/pdf Object)

[chuck kottke]

I'm just going to have a stream of thought here:P:

Basically, batteries can pack a lot of power, so-to-speak, but when they run dry, they either must be swapped or recharged. Swapping is bulky (though one could envision a "battery tray" that sits beneath the vehicle, and gets' lowered and swapped quickly at a filling station.) I think the electrics will need something like that; although maybe customers can wait the 10 minutes to an hour for a fast recharge? Sounds a bit troublesome, but perhaps this will be acceptable??

Fluid fuels have the advantages in that (1) they are incredibly energy dense, (2) they are easily stored and dispensed, and (3) they use oxygen from the air for half the reaction energy. Since they have such nice dispensing and storage properties, and are so energy rich, they are hard to compete with. 2 minutes at the filling station, and you're set to go for 100's of miles down the road.

Here's where the challenge is: can we make them in an earth-friendly manner? can they be made in sufficient quantities? can they be made and handled safely?

My biggest green contention is the same as Fuller's - do more with less, so everyone can enjoy more. There's so much to be saved in efficiency measures that it's next to obscene! If even Diesel engines are around 30% efficient, and Carnot's efficiency predicts 87% maximum (without blowing up the engine), we should be able to double the engine's efficiency. Then, looking at where the power's headed, it's equally ridiculous in inefficiency. Idling takes up 17% of the energy the engine makes?? Why idle! So, it's clear as day we need true hybrids.

A smaller engine, that only runs when needed, and functions as a generator set for the electric automobile. That way, long trips aren't an issue.

A doubling of engine efficiency, and a doubling of all non-engine efficiencies, should be possible; with 1/4 of the current fuel usage, then switching to electric battery-motor drive systems for the bulk of trips, and supplying the electric with solar canopy roofs over parking lots, etc., we should be able to decrease fuel demand to 1/16th of the original needs or less, and as time goes by, that figure could be further reduced to 1/32nd.

With a demand for fluid fuels for automotive use down to 1/32nd of the current demand, then the use of bio-fuels made through efficient means makes sense. And the good news is it will save us all the unneeded expenses of buying barrels of fuel, and help out the environment at the same time. Plus, the vehicles will be less hot in the summer, will cool down more efficiently, and save oodles of money to operate, all while helping out the environment.:)

[a_face_of_light]

I really feel hydrogen is the best alternative as it's liquid based, gives similar milage and is not inconvinient like electric batteries, I would definatly prefer a hydrogen car to an electric one.

[Black Rose]

But the problem of hydrogen is getting it stored into it's liquid form.

 

I like the idea of the GM Volt, a small petrol engine used to charge up the batteries only.

[RICK8]

My car is very green..:p

[Black Rose]

Where my car isn't very green, it's very blue.

[Hotplay007]

 

hey the rims look like lime slices :P

[Black Rose]

 

Me likes

[RICK8]

I would never buy an american car. Or european for that matter.........

[Black Rose]

So what would you buy instead Rick?

[chuck kottke]

But the problem of hydrogen is getting it stored into it's liquid form.

The hydrogen vehicles today generally use adsorber materials to concentrate the hydrogen gas onto a solid surface. Hydrogen is so tiny, it easily sticks to many things, and finely divided materials work well. Hydrogen adsorbers include Platinum, Nickel metal hydrides, synthetic zeolites, and a number of other materials. I like the zeolites myself, since they're made from common materials (they're alumium silicates).

 

I like the idea of the GM Volt, a small petrol engine used to charge up the batteries only.

Makes good sense! GM needed something to bring back interest in the company; maybe the new Volt is going to be one of their top sellers!

Something more on the Aptera from Reuters:Spaceship-like car to hit U.S. roads | Video | Reuters.com

[RICK8]

So what would you buy instead Rick?

 

 

 

Japanese of course.

[coldplay_is_louve.]

my car:

 

 

best. car. EVER. :wacko:!

[RICK8]

Hehe that's yours?

 

What's it like to drive etc?

[chuck kottke]

Actually, I wouldn't mind a car like that myself...

Here's a bit of information on a free piston engine generator, which might be ideal for a true hybrid design:28890yy.pdf (application/pdf Object)

[a_face_of_light]

What about driving an old car?, so you don't damage the enviroment further by buying a new one that has to be built.

[chuck kottke]

Hmm... well, it does take approximately as much energy to make a new car as a typical car uses in fuel in it's lifespan (which is around 12 years). A good idea, if the car you start with is reasonably efficient. If it's only half as efficient, you're better off with a new one.

But the world is weird - if we stop buying new cars, then the global economy would crash, and that would lead to massive unemployment, and a downward economic trend (worse than this one!).

So, I would advocate pushing for electrics & true hybrids, and let the sunshine on solar panels or wind turbines provide the EMF & UMPH. Best if the car is built with renewable energy, and the materials are earth-friendly.:)

Engines are so incredibly inefficient, that's a good area of research to be in; Electrics will do fine, but the time to recharge, and the bulk of the batteries leads one to realize the value of the energy-dense liquid fuels, such as bio-diesel, or even hydrogen stored in an adsorber like zeolites..

I think that engines will progress a great deal further. At 25%-35% efficiency, there's a lot of room to grow; and powerplant size needn't be so large for performance sake, if we continue to perfect electric drive systems.

[a_face_of_light]

So a Shelby Cobra or 60s Camaro is out then?:(

[chuck kottke]

Well, think of it this way - if you only drive the Shelby or 60's Camero on every-other Saturday or Sunday, then it's such a small amount of driving that it's not a big deal. ;)

I think most people wouldn't anyhow, since they're so collectible, nobody wants to risk even a ding in the finish!:laugh3:

But basically, we'll need to transition to some cool new cars, which can be hot performance machines as well - it's all a matter of good engineering. Light & strong, with powerful electric motors; I'll bet that electrics will outperform many of the current sports cars on the road today, and more so in the future.;)

[a_face_of_light]

I would go as far as to say I don't like modern sport cars at all, sure thier fast and everything but to me the older ones are so much more beautiful and cool, plus they sound kind of amazing too, I like some modern cars like the SUV I mentioned and the Peugeot 207 but if I had the choice of a modern Ferrari or that Bugatti or a 60's Cobra I would pick the Cobra every time, it isn't just about the performance but the heritage,looks and sound for me.