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Is electric powered transpo the answer?
2

Is electric powered transpo the answer?

Is electric powered transpo the answer?

(OP)
I have read many things here where folks appear to think highly of electrical transportation.  I don't think much of it because the energy needed is much higher than traditional solutions.  On another thread, it was reported that only 15-20% of the input energy at an electrical power plant was used at the final destination (e.g. the fuel content at the electrical plant contained 5 to 6.7 times the energy used in the home).  This is because they are unable to capture all the energy in the fuel, there are productiion losses such as friction in the generators and turbines, and there are transmission losses.  I do not know what the ratio is for petroleum IC engines, but I am under the impression it is much better than this.  Are there any automotive engineers here that can provide some comparisons?  Thanks.

RE: Is electric powered transpo the answer?

figure 33% of the fuel energy can end up as mechanical energy at the flywheel for a 4cyl Honda

figure 40% for a small diesel

hard to put a nuke plant under the hood in either case.. .electrical works better for that
 

RE: Is electric powered transpo the answer?

Assuming electrical powered transpo. is a light rail system with which can hold 40-80 people pure trip from a suburb to a city. I would say that is about 40x-80x more efficient than personal car transpo. from the suburbs to a city... O but I forgot the American way is for every person NEEDS to drive there own extremely inefficient vehicle for their daily commute and most major metro area's have a neglected public transit system so pubic transpo isn't even an option...sry I think I miss read the OP

Overhauling the transportation system would probably be the best way to "go green" have support Al Gore, but that would require politicians to actually do something useful to improve infrastructure, as apposed to telling people to drive hybrids while they continue to do nothing and line their pockets with public funds.

Maybe I am having a bad Friday....
 

RE: Is electric powered transpo the answer?

O did i mention how the NEED to own land and suburban sprawl has ..... OK OK i will stop...

RE: Is electric powered transpo the answer?

Once we have fusion, or an overflow of renewable energy sources generating electricity, or at least nukes on the french scale sure.

Until then for personal transport I'm not sure how much sense it makes.

Of course same goes for hydrogen.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

For steam cycles, there is a max theoretical limit for  efficiency elucidated by someone named Carnot:

Carnt Efficiency = (Th-Tc) / Tc

Where Th and Tc are the heat source and heat sink temperautres respectively.

This does not include any friction... just a thermodynamic fact (Something to do wtih entropy) that you have to reject a lot of heat to your condensor (wasted heat) in order to keep the cycle running.   A typical nuke plant puts twice as energy (heat) into the cooling reservoir as it does into the generator (mechanical work into the generator before converted to electrical).

Then there are the traditional more easily understandable losses due to friction in tubine, generator, electrical losses in generator, transformers, lines, etc.

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

RE: Is electric powered transpo the answer?

Although centralized electric plants plants tend to be inefficient for reasons mentioned, motors tend to be tremendously efficient compared to engines. Also you have to consider differences in size/weight of coponents that need to be carried on the vehicle of course.

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

RE: Is electric powered transpo the answer?

"motors tend to be tremendously efficient compared to engines"
That is just looking at input/output quantities of motors vs engines... doesn't take into account upstream inefficiencies.

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

RE: Is electric powered transpo the answer?

personally i'd prefer an electric car to a hybrid (fuel cell).

RE: Is electric powered transpo the answer?

One side issue that is always neglected in these discussions is water usage in central facilities.  A 200 MW plant evaporates something on the order of 20 million gallons of water a day in rejecting heat to the heat sink. Water issues in the Western US are often bigger problems than the price of fuel.  Sure, the evaporated water will fall as rain somewhere, but most rain falls on the oceans and is lost as an easy water source.

In the end, all of these issues are pretty much moot.  With a bunch of assumptions about energy required to transport gasoline to stations, mechanical and thermodynamic effeciencies of electric plants and motor transport; vehicles on the road represent something like a 1,200,000 MW load--does anyone think that we have anything like that much spare generating capacity or the werewithal to build it?  According to the EIA, summer electric-generating capacity in the US is 990,000 MW, so this is at least doubling capacity.  In 2006 the US added 12,000 MW of capacity.

"Going electric" is kind of like the transition to a hydrogen economy--the practical and engineering hurdles of the real problem far exceed our ability to solve them with today's technology.  Will technology evolve to provide as-yet undreamed of solutions?  Probably, but when?  Linear thinking is just not going to solve the truly horrible energy problems that have been on the horizon for 50 years, but didn't get much attention until the news media got their teeth into the dual story of "Global Warming" and "High fuel prices".  

Energy is so cheep in the world today that without these manufactured crises no one would be talking about alternatives.  If you don't think that energy is cheep, realize that up until about 1800 a family would expend about 1/2 of their waking life in the acquisition of energy sources (chopping fire wood, transporting it, cleaning out the ashes, etc. and they mostly went to sleep at dark), today it is on the order of 1/8 in the developed countries and still very close to 1/2 in many "developing countries".  Cheep energy brings many fair and wonderful things, but take it for granted and waste it at your peril.

David

RE: Is electric powered transpo the answer?

Quote:

Also you have to consider differences in size/weight of coponents that need to be carried on the vehicle of course

... and the weight of fuel.  An electric train carries none.

- Steve

RE: Is electric powered transpo the answer?

Many good points here, especially Zdas's about the water impact of electrical generation, and Gymmeh's point about electric rail vs personal transportation.  Electric light rail is the only long term solution IMO, having ridden such public transit systems for many years.  As pointed out, the real primary issues are sprawl and the SOV use that results.  So my point is, I don't see ANY potential gov't program that has any chance of moving people closer in, to achieve the population densities needed to make light rail economically viable.  Nor do I want the gov't to even try, it will surely be a waste of our money.

What I want is for the very real power of supply and demand, economics, to make this happen.  The less the gov't interferes, the quicker the economic reality will start to hit home.  People already claim to be choosing between fueling their SUV's and buying food;  while I have a hard time believing there is any question which to choose there, maybe the light bulb will come on and these people will change their ways in the near future.   

RE: Is electric powered transpo the answer?

I think virtual travel may be the key to reducing our need for individual travel. If the quality of communication could be improved to the extent that we don't have to go there physically then we could reduce individual travel. Consider shopping, given the suburbs will be there for quite a while. Thousands of us could each get in our cars or SUVs and go to the mall, make our purchases and drive home. With better communication we could virtually go to the mall, make our purchases, and a few trucks could make the rounds delivering our purchases. This approach can be applied to school, vacations, and work. Maybe we should research in this direction, instead of windmills, ethanol, electric cars fueled by nuclear power, soya beans to diesel, tidal power, and clean coal. Its a tough subject to Google but "virtual travel" is a starting point.

HAZOP at www.curryhydrocarbons.ca

RE: Is electric powered transpo the answer?

OWG,  that would be ideal, but I've worked at companies that tried the "virtual office" backed with the full complement of electronics.  Just didn't work in an environment where collaberation was required (project engineering).   

RE: Is electric powered transpo the answer?

There are a gozillian different retail ways to improve overall fuel consumption.  Denver has light rail with a Park & Ride concept that is very well utilized (but there are always complaints by RTD that the systems loses money even with full trains during rush hours).  

Many tasks can be done very well via telecommuting (in my business I typically don't leave my home 4 days a week on average), collaboration over telephone lines, e-mail, and net meeting are all less effective than face to face, but they are often good enough.  I'm chairing the program committee for an SPE Applied Technology Workshop, and I insisted on a face-to-face kick off meeting so everyone would be able to see faces, and the next time we'll see each other is at the ATW--so far it is working fine to hash out the details with virtual meetings.

At the end of the day, all of these things combined will not make a significant dent in what I see as the main problem--the U.S. is importing $1.7 billion/day of hydrocarbon products.  No economy can stand that kind of bleed indefinately.  The price simply has to increase enough to impact each individual's disposable income enough to make them change--supply and demand is really the only effective tool.  

Back to the topic of this thread, electric vehicles (like biomass fuel) will never be more than a side show unless someone comes up with a way to solve the difficult problems.

David.

David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.

The harder I work, the luckier I seem
 

RE: Is electric powered transpo the answer?

RossABQ - I too have tried a version of Virtual Office on a project with limited success. The technology needs a lot more development before it can make a major impact.

HAZOP at www.curryhydrocarbons.ca

RE: Is electric powered transpo the answer?

(OP)
The point made by Zdas04 is along the lines of what I am concerned about.  I hear folks speak of the cost of gasoline and then speak very cavalierly about just switching over to electric cars to avoid buying gas and reduce emisions.  I don't think they get the impact to the electric grid and that with all the efficiencies computed they would probably not be any less of an impact for emissions.  I also think this a failure of the mass media to ask the right quesitons so folks get a better understanding of the big picture.

RE: Is electric powered transpo the answer?

Dinosaur, this is the same mass media that tout 'water powered cars' when they mean hydrogen powered, with the hydrogen coming primarily from electrolysis and hence effectively electricity.

While not the only hurdle, until they determine where all this extra, presumably clean, electricity is actually going to come from any variation on electric vehicles, hydrogen power or even large scale plug in hybrids faces a masive hurdle.

I'd guess one of the big advantages of electic & plug in hybrids is the use of regenerative breaking but I don't think it's enough to overcome the above concern.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

I think one reason the need to recharge electrics is skimmed over is that it is assumed to occur during off-peak hours, which is largely true.  The environmental impact (coal-fired emissions) is still there.

RE: Is electric powered transpo the answer?

Good point Ross, in terms of the infrastucture you can get so far/some benefit only recharging off peak, maybe the charging unit can even be turned off by the electric company during high demand.  

However, as you start to point out, except on a small scale, with the current infrastructure you'll start to increase emissions from electrical generation.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

There's no way to tell right now.  If fusion becomes viable, electrically powered cars become viable.  If CO2 turns out not to be a problem and the scammers are overruled, gasoline (rather probably diesel) made from coal will keep us going for centuries.

RE: Is electric powered transpo the answer?

At least with electric transport (hopefully mostly trains with SOME cars) there is a HOPE of using renewable energy sources to supply them.  The special needs of transportation (ie. lightweight, high energy density storage or a distribution grid usable by the vehicle while travelling) make the direct use of renewables as fuels very difficult.  So what you get are over-hyped pseudo-alternatives like corn ethanol and canola biodiesel- taking food and turning it into fuel.  

There's not enough agricultural biomass generated on earth, forgetting about our food needs, to eliminate our dependance on fossil fuels at CURRENT levels of consumption.

That we haven't maximized the use of renewables for our stationary energy requirements yet is a direct result of the economics being skewed toward processes which dump stuff for free into the atmosphere (ie. coal).  Until wind costs LESS than burning coal, there's no incentive to do anything else other than to burn coal, so that's what we will do.

 

RE: Is electric powered transpo the answer?

Of course another way to look at "dumping stuff for free" into the atmosphere is that we are increasing the potential biomass in the biosphere by increasing the level of CO2 in the atmosphere, as CO2 is the base of the food chain.  

It could be, once we know more about the carbon cycle and climate change feedbacks, that emission of CO2 is a positive thing, increasing the food supply - especially for third world countries.

RE: Is electric powered transpo the answer?

It ain't called the greenhouse effect for nothin'- ask anyone who runs a greenhouse what kind of increased agricultural production you can get out of doubling CO2...

RE: Is electric powered transpo the answer?

I don't know anyone who runs a greenhouse, could you enlighten us?

David

RE: Is electric powered transpo the answer?

I don't get the joke .. if there is one.

Big glass shed full of (possibly legal) plants.

- Steve

RE: Is electric powered transpo the answer?

As others have previously posted, with the current technology it's probably easier to have stationary power (electrical) generation that's either 'green' or at least free of imported oil (or whatever your justification for changing the status quo is) than to put it straight into personal transport.

Potentially this could then free up natural gas from being used in stationary power which can relatively easily be used in existing car technology etc.

Of course, we've gone and spent the money & effort on those gas power stations and aren't going to stop using them anytime soon(even if we could build alternative sources quick enough), probably not before their natural end of life in a few decades, due to the investment made.

By the time we could stop using it for stationary power natural gas will probably be in a similar boat to what oil is currently, so you're back to square one.

Maybe we've already missed the boat for this line of thought.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

Some numbers awhile back bugged me a bit... the quote from the OP is ~ "15-20% of the input energy at an electrical power plant was used at the final destination".

Ok.  But, then:

"figure 33% of the fuel energy can end up as mechanical energy at the flywheel for a 4cyl Honda"

Hmm.  Both statements are apparently true.  But I think the comparison is unfair.  The electrical efficiency assumes all losses incurred (conversion, transmission, re-conversion to useful work), essentially an end-to-end efficiency.  The automotive engine gets 33% (arguable, but maybe possible with today's turbocharged, multi-valve motors) only at its best operating point, which is essentially near-redline with near-wide-open-throttle.  Since that is not how most of those Hondas are operated, the efficiency of the engine is significantly lower in actual driving use due to operation at part-load, part-throttle "cruise" conditions (maybe more like 20-25%?  But I'd bet a bit less than that even).  Also, to be fair, the auto example should add in conversion losses thru the drivetrain, reducing the figure to something closer to 15-20% for an overall efficiency.  These are just WAG numbers, obviously, since actual drive cycles could (and do) cause a lot of variation in the average efficiency of the vehicle.

It's always bothered me that fuel-burning locomotives actually run the engine to generate electricity, which is then applied to the electric traction motors to move the train...  But it's obvious when you think about it, a DC motor can provide ample torque at zero speed, while a diesel engine would have to have a relatively inefficient torque converter with gobs of slip to allow it to move the train from a dead stop.  But why lug the weight and fuel around for the diesel?  Was told long ago that weight for a locomotive is beneficial, since it provides traction... but that arguement does not hold for passenger rail systems where all cars have drive wheels, or are so light that high traction force from the loco is not required.  I think the real answer is that diesel used to be really, really cheap.  So, no point in installing expensive overhead power lines for cross-country travel.

If electrical power is locally generated, through a distributed network of small powerplants (of whatever ilk), are transmission losses across the grid consequently reduced?  Does that argue in favor of wind/solar/small hydro/farm methane etc. etc. generation?

Hmmm.

RE: Is electric powered transpo the answer?

btrue, I was thinking similar a while back about the distributed power for an electrified train line.

I saw an article in Popular Mechanics or Popular Science about high speed rail.  One possible route was LA to Las Vegas.

I was thinking that if they set up solar power plants and wind turbines along the line (seeing as it's in the desert and pretty windy at least in parts) that would cut down transmission losses etc as well as being nice & green.

Another issue in why diesal electric not electric, what are the costs in electrifying a line & the transmission losses if far from the power plants?  Some of the lines out my way in the desert are pretty remote and very long.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

The quote from above about vehicles and MW load:
"vehicles on the road represent something like a 1,200,000 MW load--does anyone think that we have anything like that much spare generating capacity or the werewithal to build it?"
Question: how many of these are operating at one time? I know mine is turned off for more than 22 hours a day. Also a good deal of time it is just keeping it self going as I wait at a stop light. It really dosen't generate all that much power, except on vacations.

RE: Is electric powered transpo the answer?

The power required to keep a car or train moving is mostly fighting wind resistance.  There is additional power required to do the work of climbing hills, but mostly it's the wind resistance.  The additional work required to lift a heavy locomotive vs. a light locomotive is negligible compared to lifting the entire train itself.  So it doesn't matter if you're carrying a lot of fuel around.  The line losses in overhead power lines, in addition to their construction and maintenance, costs more for overland travel.  

They are used in urban commuter rail.  

Running off an electric motor has an advantage in that the diesel can be run at optimum efficiency, which more than offsets the little additional weight of the motor compared to the train.  

What I think they should do is every rail car have a battery bank so when the train's going downhill it stores up the energy from braking...

RE: Is electric powered transpo the answer?

LCruiser, that brings up a good point.

I understand that Electric/Diesal electric use the motors for breaking, i.e. turn them into generators to load the wheels.  However, based on a show I saw the other day I got the impression that this energy is then dissapated as heat (at least by diesal electric) rather than stored/used/returned to the track.

Does anyone know anything about this?  First is my understanding correct and secondly the resoning etc, I can guess part of the reasons at least historically have been financial but I wonder what technical aspects there are?

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

The experiment's been done, folks.  Google a bit and you'll see the results.  Double the CO2 and you get a 15-20% increased yield of crop fruits/seeds with a decrease in the average nutritive content thereof.

You also get an increased yield of weeds.

What you get in natural ecosystems when you do this on what amounts to an evolutionary blink of the eye is unknown.

What IS known is that biomass yield nowhere nearly doubles with doubling atmospheric CO2 as implied in a previous post (as a wishful thought I guess).  The carbon cycle is complex but it's clear that CO2 in the atmosphere versus plants on the land and in the seas represents nowhere nearly a self-regulating system- certainly not on a timescale of human significance.

And unlike global warming itself, where the complexity of climate models leads lots of people to deny the risk, nobody is denying that we're headed toward doubling our atmospheric carbon dioxide concentration, nor that we humans are responsible for this change.

 

RE: Is electric powered transpo the answer?

Trains have a ironic twist compared to cars;  the locomotive HAS to be heavy, as tractive force is a function of weight.  There is absolutely no incentive to design a lightweight loco.  I took a Railroad Engineering course as my senior elective and it was a fascinating course.  Winds affect trains more than you'd think, the worst situation is a quartering wind:  it pushes the flanges of the wheels against the far side rail, greatly increasing friction.

PS -- the perenial winner of the "lowest utilization award" for machinery is the automobile.  As noted, not used anywhere near capacity.  The index is meant to track production tool utilization, but vehicles are considered a capital tool.

RE: Is electric powered transpo the answer?

Ross, I saw something on high speed trains recently where it seemed mass was an issue, presumably due to acceleration demands (I can't recall), and so they made efforts to reduce their mass.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

If you are talking about self-propelled (train) cars, where each car has its own motive power (typical of some light rails), weight might be an issue.  Chicago's EL trains are each self-powered this way, allows for more flexibility (adding cars).

RE: Is electric powered transpo the answer?

I think what I was looking at was about the TGV & 'Bullet' train etc.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

High speed trains are people movers.  I think we've been talking about freight trains.

RE: Is electric powered transpo the answer?

Diesel-electric locomotives dissipate braking energy as heat because there's no easy way to store it. There are many possible storage methods such as batteries, supercapacitors, flywheels, thermal storage using molten salt, etc., but given the relatively low cost of diesel it's much easier and cheaper at the moment to simply dump the heat as waste.

If locomotives ran on hydrogen it would be possible to use the waste electricity from braking to generate hydrogen and oxygen from the electrolysis of water, which could be used as fuel later.

Fully electric trains (relying on remotely transmitted power) can and do contribute their braking energy back to the 'grid'.

It's my opinion that an immediate policy shift towards electrified rail could save the US a lot of grief in the coming decades.

RE: Is electric powered transpo the answer?

You can make a train more efficient by supplying the loco with electricity so it can do regenerative braking back to the grid.

That said, diesel is still so cheap that an enormous fraction of North American freight is moved by truck rather than by train.  Hell, the city of Toronto currently TRUCKS its garbage to a landfill in Michigan, since there's no direct rail link- oh yeah, and because the roads are funded through public taxes whereas the railroads have to maintain their own rails...

RE: Is electric powered transpo the answer?

Electricity as an answer, what is the question?

RE: Is electric powered transpo the answer?

Ha, ha.

thread730-215374: DeKa Slingshot Segway.  

There's a solution (electric as I recall), but what's the problem.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

I don't doubt that diesel on rails is efficient.

After looking at the Denver light rail yesterday, there seems to be a bunch of added stuff to the cantanary part.
I wonder if the electric trains are any less maintenance intenssive than the diesel?

RE: Is electric powered transpo the answer?

Based on recent experience in diesel-powered "heavy rail" passenger service initiated in Albuqerque (on freight lines):

Must be dedicated right of way with NO grade crossings (5 people killed so far crossing the tracks in cars/trucks).

Rules for blowing the horn at grade crossings is a real problem, typical rail practice is a very loud horn, for an extended period.  Neighbors don't like.

Diesels are quite noisy near stops (acceleration).

Quite a bit of parking and support structure is needed to integrate it into the existing auto systems.



 

RE: Is electric powered transpo the answer?

As many other have said, it depends on how the electricity is generated.

In Australia, I believe that emmissions standards on cars are more stringent than those on coal powerstations, so switching to the electrical grid may actually cause more emmissions.

In some ways hydrogen cars may make a better environmental alternative. The hydrogen can be created where there is a good environmental source of energy(solar, hydro,tide, or geothermic) and at an off peak time and then shipped to the required location(in a hydrogen powered truck of course).

RE: Is electric powered transpo the answer?

Ross,
"Quite a bit of parking and support structure is needed to integrate it into the existing auto systems."

You still need to have parking, whether its at a "Park and Ride" (which is normaly free/cheap) or whether its downtown in a garage ($5-$20/hr). People have to put their car somewhere.
The major difference is the suburbs have large amounts of space to place parking, downtown space is a premium.
 

RE: Is electric powered transpo the answer?

(OP)
It seems to me we are having three discussions.

The discussion I would like to have concerns using electric powered cars rather than IC powered cars.  This is the concept that I want to evaluate.  There are two hurdles.  Can we generate enough electricity to add the transportation power needs to the other demands on the electric grid?  Would Americans be willing to accept the electric car that could be brought to market?  (e.g. How much would an electric car cost that would compare to a midsized American car?)

I accept that rail transportation is efficient.  I am actually a huge railfan, except I don't think it is economically viable in the US.  I also accept that we should be using nuclear technology and other technology to generate electric power.  But these are side issues.  I just don't think folks appreciate the scale of the problem this represents to the electric grid.

And regarding the observation that a trains dynamic blows off energy as heat, I always wished the railroad could find a reliable rechargable battery that they could put in a "slug" when they travel downhill on a long division.  Then these charged slugs could be used to pull the next train uphill.  I'm sure there is an economic reason they do not do this.  And it could be that diesel fuel is just that cheap.

RE: Is electric powered transpo the answer?

Once we reach the stage where diesel fuel is no longer cheap, will we be able to afford a massive infrastructure changeover towards electric transport?

RE: Is electric powered transpo the answer?

I'll switch my daily driver in a heartbeat.  Needs to be reasonably comfortable, 40 mph, 60 miles per charge.  2 seater would be okay, 4/5 seats better.  Cost not too much more than a hybrid, and battery life > 10 years.  It's those last two that aren't here yet.

But...if we assume distributed power, and put a grid of conductors all over town...everybody could drive bumper cars, like at the amusement park.  There wouldn't be much difference in actual commute-hours driving speeds (at least in THIS town), and then all the cars would just bounce off each other instead of crunching and blocking traffic whilst the drivers stand in the middle of the road staring at the damage and talking on their @$$^$# cell phones...

RE: Is electric powered transpo the answer?

I'd go for an electric car that was the size of the old King Midgets (2-pass, 1200 lbs tops, 10" wheels), using deep-cycle lead acid batteries that last 2 yrs, and only cost $50 apiece.  40 mph/40 mile range is acceptable.  No A/C, RIM body panels, a radio and crank windows.  Cost must be under $10k.

It wouldn't replace my gas car, it would be solely for daily commute and errands, 90% of my driving.

RE: Is electric powered transpo the answer?

There are two problems with electric cars.

The first has been talked about a fair bit here. That is the need for expanded generation and transmission. It is possible to expand the current generation capacity using "green" technology, mainly through solar farms and expanded hydro-power. Some areas may extend that to tidal power as well.

The main issue is the size of the investment required. Longterm it may pay off, but the size of the projects required means that they will not be done without government participation. And governments tend to think in the shortterm, as longterm successes don't help at the ballot box.

The second issue is battery disposal. The most efficient batteries are laden with some of the most toxic materials around. Treatment and disposal will also require large costs.

IMO the electric car is more realistic than the hydrogen one. Hydrogen has the current hurdles of finding an effective storage system, developping and entirely new transmission system, consumes huge gobs of water and still needs as much added electric generation, if not more. Unless someone come up with a catalyst for electrolysis, hydrogen is likely less efficient.

As a side note, the comments about charging at off peak hours having less impact are somewhat false. It has less economic impact on the utilities as power is cheaper during off peak hours, but it has roughly the same overall impact on the grid. Many hydro-electric plants only operate at peak capacity during peak hours in order to maintain reservoir levels and maximise profits. For example, BC Hydro operates at full capacity during peak hours and sells power to the US. During off-peak hours they import power. Due to price differences this results in large profits.

RE: Is electric powered transpo the answer?

In 1980 my senior design project was a review of the lead-acid battery industry's ability to meet a demand ramping up to 10 million electric cars by 1995 (the whole senior class in IE got a piece of the Professor's DOT project, but he got the whole pay).  My group's conclusion after a semester of danged hard work was that the major bottleneck was a couple of elements that were added to the battery (I don't remember what they were).  These elements were mined in some pretty unstable economies, and the demand projections indicated a need for several hundred times as much of this stuff as was currently being mined.

Our conclusion was that a major breakthrough would be required in battery technology to make widespread electric cars viable.  The electric-grid team came to a similar conclusion.

I know there have indeed been some major improvements in battery technology over the last 28 years, but I'm confident that every one of them will have some choke point that will make significant production increases difficult or impossible.  There are A LOT of cars on the road, and as long as fuel is cheep, there will still be a lot of IC engines on the road.

David

RE: Is electric powered transpo the answer?

Fossil fuel use won't end with a bang but with a whimper.  epending on the location and application other sources will become more viable.  First short commutes plugged in overnight, then longer and longer.  The caveat to investing is the fact that convection in the troposphere invalidates the simplified concept of "global warming" so the opposing forces are reality and the propaganda of carbon traders like Al Gore.  Coal to oil conversion is pretty efficient, but it's not free, so somewhat higher prices will result - but there is enough coal to last for centuries.

RE: Is electric powered transpo the answer?

owg,

I think mad max was called 'road warrior' in the US. Beats me why hollywood insists on 'dumbing down' the titles here in the us.

Anyway, I can see it happening in London. If the London Borough allows electric cars to avoid paying the central london access fee then I can see them taking off.

RE: Is electric powered transpo the answer?

Dinosaur, sorry for taking this off track, on the bright side it hasn't yet decended into another 'global warming exists, not it doesn't, yes it does but it isn't linked to fossil fuel use...' debates.

Quote:

Can we generate enough electricity to add the transportation power needs to the other demands on the electric grid?
  Yes, I'm sure the US could build lots of coal power stations if it wanted.
Now as to all the implied questions: Can we generate it 'cleanly',  well it will depend on your definition of clean but I think there are big hurdles.  Can we distribute it, probably not without significant upgrades to current distribution system but I'm no expert.  Will environmentalist & nimbys etc allow all the power plants to be built, probably not.  Will anyone want to spend all that money in anywhere near the short term, I doubt it.

Quote:

Would Americans be willing to accept the electric car that could be brought to market?  (e.g. How much would an electric car cost that would compare to a midsized American car?)
  In the short or probably medium term I doubt the American public will accept likely offerings on a large scale.  America more so than where I used to live is addicted not just to the car but to large cars (& trucks).  Even of those who would be willing to drive smaller vehicles many of them seem scared to because they think they'll be run off the road by all the trucks & SUVs.  If you want to get an idea of cost take a look at Tesla.  OK at the moment they only have the sports care but I believe they're working on sedan.
I think in the shorter term plug in hybrids will be more attractive than battery power alone.  You still get to regenerate energy (not sure that makes sense as written, I mean capture energy othewise lost in breaking) and potentially make short/slow journeys on electricity alone.  The total electrical demand will be less and may fit in better with off peak charging (as you can always travel on the IC even if the power company wont let you charge the vehicle due to demand).  I'd be interested how series rather than parallel hybrids compare once you have the plug in element.

I propose we all buy old British Milk floats, stick a pallet of batteries & diesal generator on the back & see what happens!

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

The efficiency gains of hybrids come in large part from capturing the energy used for braking, as stated.

Is there any significant benefit in being able to adjust the loading on the gas engine (by adjusting generator) so that the gas engine operates near some kind of "best efficient point"?

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

RE: Is electric powered transpo the answer?

The energy captured from regenerative braking is stored and used to supplement the IC engine's peak demand.  Hence a good portion of the efficiency comes from not having to lug around a larger, more powerful (and less efficient at idle)IC engine merely to satisfy the horsepower requirements the driver has 10% of the time.

If the hybrid powerplant is large enough, you could imagine running the engine at a max efficiency or lowest emissions point and then modulating gently around that point based on power demand.  But in reality most of the hybrid systems for sale at the moment are really just performance enhancement for modestly smaller IC engines- some of them so tiny to be basically "green-washing" rather than of any real use.

RE: Is electric powered transpo the answer?

Hence my comment on series rather than parallel Hybrids.

At present as far as I know the hybrids on the market are all more or less parallel.  i.e. at higher power they use both the electric motor & IC engine.  At lower power they may use just elecrical, if enough charge etc.  At times they'll use just IC.

In a series hybrid there would only be the electric motors.  They'd need to be bigger but you would have a simpler gear box/powertrain, at least potentially.  The IC would run just to keep the batteries topped up.  As such it could always be run at optimal efficiency.

However depending how you look at it for some of the time the IC is effectively dead weight - especially for a plug in series hybrid.

I believe their may be series hybrid busses on the market.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

Thanks moltenmetal and Kenat.  I hadn't digested the whole thread... missed the part about discussion of mass of the engine.  Makes sense that is another very important part of the equation.

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

RE: Is electric powered transpo the answer?

With the Prius there is a technique where the accelerator is pushed only slightly, resulting in the IC engine staying off and the car running on electric only. It's also possible to install a switch to turn off the IC when desired.

Although the capacity of the Prius batteries is small, very good efficiencies are attainable by using the electric only for acceleration, and the IC for cruising (where it'll run at a constant maximally efficient RPM).

My father did a home-brew EV conversion of a 1970 Citroen a few years back (a great car). He installed a small IC generator in the engine compartment which would top up the batteries for longer trips - it added about 15% to the range.

He started with lead-acid batteries but he recently bought a pack of lithium-ion for his Scion xB conversion, which will get double the range (100 miles) at half the weight.

RE: Is electric powered transpo the answer?

Should have said, in the Prius and similar vehicles at the moment I believe electric only will only get you to about 25-30mph, the electric motor isn't big enough for more (without wind/down hill etc)

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

For short range cars battery technology is most easy.  The only power source that I see after coal is outlawed (global warming) and natural gas runs out (nuke is already unpopular) is wind.
Prices are coming down and the only real problem is transmission.  Long haul transmission can overcome local calm problems.  Photovoltaic is too expensive.  The available wind energy in the US far exceeds its energy needs.  
Pumping energy into a car with magnetic fielsd might be easier than sliding contacts, if it comes to that. I already verified that it would be force free.

My friends are building battery powered cars and my next will be electric.
Has anyone made the riders pedal yet?  

RE: Is electric powered transpo the answer?


The Prius does modulate its engine speed so that for a given power output it always operates at its most efficient throttle opening. At any power output above idle its efficiency is greater than 30%, on this operating curve.

It does this by being able to run at /any/ effective gear ratio, and using the battery as a  buffer so that the engine can always sit on this operating curve.



 

Cheers

Greg Locock

SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.

RE: Is electric powered transpo the answer?

That is the same point I raised a couple of weeks ago.  Water use/waste is a really big and growing issue.  I worked on a project a few years ago to try to bring Oil & Gas produced water to a power plant to reduce their use of potable water.  The project looked good, but our short sighted legislators looked out their windows and saw it clouding up and killed the project.

To say that this country's energy policy is short sighted is like saying that the universe is kind of big.

David

RE: Is electric powered transpo the answer?

http://www.npr.org/templates/story/story.php?storyId=90042092

From article:
Designers envision something called a personal rapid transit (PRT) system.  "Really, all it is is a car," says Scott McGuigan of CH2M Hill, the construction firm that's building Masdar City. "It's a simple vehicle [for] six passengers. It's designed like a car, but obviously it's powered by solar energy with batteries."

These solar-powered cars would run under the city like a subway system. But McGuigan says the cars wouldn't run on fixed routes. Basically, they'dl take you anywhere you wanted to go.  McGuigan says PRTs represent an energy-efficient way of moving people among roughly 1,500 stations.  

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376: Eng-Tips.com Forum Policies to make the best use of Eng-Tips Forums?

RE: Is electric powered transpo the answer?

I hope the Masdar City project is successful. Oil wealth and energy has allowed population levels in the middle east to balloon to unprecedented levels (in one of the harshest environments on this planet), but sooner or later oil production will dwindle and they'll find it impossible to sustain their recently modernized civilization. Hopefully more middle eastern leaders will recognize the seriousness of their situation and come up with plans for a post-oil transition.

RE: Is electric powered transpo the answer?

Some communities have electric buses.
The UK had electric milk floats for decades which suggests that goods ought to be received in some peripheral transit area and carried into the community, to shops, factories etc by electric powered vehicles.

But the problem is the batteries. They are expensive, add weight and are themselves a major "end-of-life" problem.
The alternatives are electric trams, trolley buses etc.
Indeed, having pulled up all the tracks and overhead power lines for trams they are now being re-introduced in many cities. They are clean quite and efficient.

However, to be of real value I think some similar approach is needed for the car. Most people drive on paved roads almost all of the time.
If the major routes were provided with some form of power grid then hybrid cars could transition from petrol/diesel to electric and not have to carry batteries. If an all electric car was proposed then it would need small batteries to transition it from minor roads to major and from the driveway to the roads. Once on the gridded roads it could re-charge its batteries on the move. I would think that could significantly reduce the necessary battery size, weight and cost and perhaps avoid the need for special steels in the car construction and maybe extend battery life.

Think dodgem cars or think full scale Scalextrics (slot racers) and consider that anything that threatens to electrocute jay-walkers would have to be a good idea. Cyclists too, especially express messenger cyclists.

Bring back the C5 for pedestrian areas and city centres?

JMW
www.ViscoAnalyser.com
 

RE: Is electric powered transpo the answer?

Possibly a high current wire with an AC signal could be buried in the center of a lane, and a secondary winding could both power and guide the vehicle - off track, lose your power or set off a buzzer or turn off cruise control or something like that.  Too many drivers would probably fall asleep though - forget the "guide" idea...

RE: Is electric powered transpo the answer?

Will the US electric grid support the added load of electrified transport? Recent deregulation of the power industry has left the transmission infrastructure starved for investment. Brownouts and blackouts may occur more often even without electric vehicles.

http://www.theoildrum.com/node/3934

If solar becomes cheaper a personal solar charging station would become feasible.

RE: Is electric powered transpo the answer?

Maybe they could use the in-road power system as a transmission line too...

RE: Is electric powered transpo the answer?

Can't believe I forgot to repeat myself.  A while back (year or two?) similar discussion came up in another thread.

One idea I had is to make exchangeable battery packs.  Perhaps on the underside of the vehicle.  Drive to a 'battery' station, pull over a pit (with guides/cover etc. so you don't drive into the pit!).  A robot exchanges the battery pack for a fully charged one.  You get charged for the electrical energy in the pack.  The station recharges the packs....

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

KENAT, Got a patient on that idea?

...Seriously, awsome idea

RE: Is electric powered transpo the answer?

I'm very patient.winky smile

Oh you mean Patent.  No, maybe I should but it's in the open now and can't be patented if I recall correctly.

Maybe I could sell it to my brother in law, he works in the electric industry.  Then again his company wasn't fussed by my idea of integrated off shore power plants.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

Apparantly I'm a bit late again, darn.  If only I'd had this idea back when I was a teenager!

http://www.freepatentsonline.com/5301765.html

Quote:

If there was an exchangeable battery, an infrastructure of relatively ubiquitous charge spots and battery exchange stations, and a mobile operator that would own and operate the infrastructure as well as all of the batteries -- and if I could subscribe to this operator for miles, just as I now subscribe to AT&T for minutes -- under those circumstances I would love to own an electric car!
— Mike G., Tenafly, NJ
from http://community.nytimes.com/article/comments/2008/05/13/business/13auto.html?s=1&pg=2
http://www-formal.stanford.edu/jmc/progress/batteryswap.html

http://blogs.business2.com/greenwombat/2007/10/silicon-valle-1.html

http://www.electroauto.com/info/bat.shtml

http://earth2tech.com/2008/04/21/project-better-place-gives-details-gps-cell-phone-plans-and-speedy-battery-exchange/

http://www.patentstorm.us/patents/5301765/description.html
 

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

If I recall GM tried the pilot wire in the road idea, or more correctly magnets embedded in the road. (Now where did that disappear to)?

As far as power distribution over the power network, I recall that there is plenty of capacity for at least 8 to 12 hours a day (more correctly at night. Which happens to be the same time most of the wind power happens here.

Solar works fine until a nice hail storm. I guess you can park your car under something (can't get much sun that way).

The elecrtic industry is capacity limited by goverment regulations, but get rid of those and the capacity will show up.

How about parking meters attached to power outlets?
 

RE: Is electric powered transpo the answer?

How about parking meters attached to power outlets?

We have had those in Canada for a long time. We call them block heater outlets.

HAZOP at www.curryhydrocarbons.ca

RE: Is electric powered transpo the answer?

What does a block heater have to do with electric cars?

Unless you are talking about the block design of most batteries.

 

RE: Is electric powered transpo the answer?

cranky, in cold parts of the world I'm lead to believe that you plug your car in overnight so that the battery doesn't die.  I believe in some instances there's even some heating involved, perhaps of the engine block, not sure.

I guess north of the border these are available out on the street and are called 'block heater outlets'.

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

I won't exchange my nice new battery for someone else's rat eaten beast.   But I got solar and wind.   I drove only 25 miles this week.  So I need only a third of a battery.


The block heaters are 100 watts and they go in the dipstick hole to warm up the oil and block.

I came up with an old energy saving idea. I use a 10w "brown devil" resistor heated by stored photovoltaic (a pile of laptop batteries) as a hand warmer.  Now I can turn down the thermostat 2 degrees.  Also an electric blanket on the sofa works good.

RE: Is electric powered transpo the answer?

The replaceable battery on a pallet idea has been kicked around for ages.

My plan - lease the battery from the supplier. Each battery is fitted with condition monitoring etc.

When you exchange a discharged battery for a charged one at a service station (drive in, robot undoes 4 bolts, takes old one away, bolts in new one, from under the car).

You are billed for (a) total usage of battery (b) net difference in state of charge (c) any damaging currents.

You get credit for returning a battery that is more highly charged than it was when you borrowed it it in the first place.

Therefore your risk is limited to having to drop into a servo again to replace a poor battery, it won't actually cost you anything. The condition monitoring should stop that happening.

Your car will be fitted with the same monitoring gear - any discrepancy will be flagged to you.

Now that is all fine and dandy. There is however a bit of a problem. What does the servo do with all these dead batteries? It needs to be alongside a powerstation.

Note that this would allow you to charge it at home, or off the engine, and keep the same battery for as long as you like.


 

Cheers

Greg Locock

SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.

RE: Is electric powered transpo the answer?

The battery pallet could work in some places.
There is a streach of about 200 miles East of here where the only fuel is very high priced, if you find them open.
For traveling past there you need to take care. So how would that work with batterys?
There's the issue, the vast distance in parts of the US, and probally other countries to. Then the issue of cold on the batteries, and the reduced capacity.

The other side is the heat in some places that tends to reduce battery life.

Nothings perfect, but the energy density just dosen't seem to be there in batteries.

RE: Is electric powered transpo the answer?

My second thought on the battery is that...if a robot can take it off... some punk kid can take them off.

 

RE: Is electric powered transpo the answer?

Crazy idea that someone's probably already though of # 2 –Structural Batteries

Got the idea thinking about armored ships, vehicles, Aircraft etc.  Early armored craft typically had the armor as almost an after thought, added to a basic shell/frame or whatever.  As such massive weight penalty with little or no structural benefit from the armor.  Over time some designs started using the armor as part of the structure, leading to mass savings and/or structural improvements.  (Bad news was/is that structural armor designs tended to be harder to repair if the armor was/is damaged, so it's not universal even today I believe.)

So making the batteries structural could perhaps have the same benefit.  No idea yet how you'd achieve it, or if there's any way it's practical but I'm throwing it out there.

As to Crazy idea #1 that someone had already thought of...

wvphysicist sorry I didn't spend the time to address most of your concerns in my post.  Next time I'll put an entire business case.winky smile

Greg, I didn't spend the time to go into details but I'd thought of most of those points.  Simplistically it would be like swapping a propane tank but of course you'd want a rebate for any net charge like you said.  Also some kind of damage fee.  And like you say you'd still be able to recharge at home, the swap would be when you don't have time to do so or need longer range.

As to what to do with all the dead batteries, well most of the charging could be done off peak, if the station carries a big enough stock to get it through the peak electrical hours without recharging.  Not sure it would need to be next to a power station but probably near at least a sub station or however you get dedicated higher power lines.

Also to help power shaving in places like So Cal the power company would be able to stop the batteries from charging, maybe even drain some in emergencies though I'm not sure how good an idea that is.  The station could also install a bunch of solar panels, or out in the boondocks wind turbine or whatever, probably wouldn't meet full demand but as a marketing tool to make all the greenies happy might work well.

So long as the mechanical and electrical interfaces are the same you could have different levels of battery, bit like the grades of fuel.  Your basic lead Acid might only get you 50 miles but the lithium might get you 100, or whatever the energy densities work out at.  The higher energy batteries would have a slight premium to cover the increased cost of the pack.  

Gymmeh, while you probably can't make it impossible for a kid to take off you can make it difficult.  You can have some kind of lock, not just the structural 'bolts', which of course might not be bolts.  You can even arrange the geometry so that you need more clearance under the vehicle to remove the pack than you get in normal driving condition, I'd say your concern is one of the more easily addressed.

As to the limited range, you could still use these packs with some kind of plug in hybrid though the mass penalties might add up (unless idea # 2 is implemented winky smile).

My biggest concern would be getting ISO/ANSI/ASME/SAE or whoever to agree on the standard size/interface of the packs etc!


 

KENAT, probably the least qualified checker you'll ever meet...

RE: Is electric powered transpo the answer?

If you had power lines in or under the HMA you could inductively charge the batteries while you were driving, then use the batteries off-system...

RE: Is electric powered transpo the answer?

A couple of thoughts-

What kind of protection do you think would be needed in an accident to protect you from an exploding battery, and what does that protection do to the weight of the car?

Eventually the government will want an extra tax tacked onto your power bill for roads and such.  Does that mean dedicated meters and outlets in our home just for charging or just a flat tax?

The cars we drive now are relatively heavy for what they are. My boss's stream liner (race car) with two V8s in it is about the same weight of a Honda CRX. The auto manufacturers would need to retool with new robotic welders and it would add about $3000 to the cost of the car.

Once a viable electric solution is on the market, what do you think will happen to gas prices? Then how will these solutions look?

Just fun thoughts.
 

RE: Is electric powered transpo the answer?

To paraphrase, gasoline usage won't end with a bang but a whimper.  In fact, oil from coal will be around a lot longer than any of us.

RE: Is electric powered transpo the answer?

This idea of inductively charging your car fro overhead power lines has been tried by a few hacker(for lack of a better term). The problem is sence they were stealing power they were prosecuted.
So for this to work you would need an electric meter on your car, and someone to read the meter, and someone to verify you haven't tampered with the meter, and more.
Not that it's a bad idea, it just needs a bunch more thinking, and a big coil or copper.

 

RE: Is electric powered transpo the answer?

Metering won't be a problem.  I don't know if you are aware of OBDII - here's an excellent dedicated reader:
http://scangauge.com/

It will be nothing to include charging information on a future version.  

To feed all the paranoiacs out there, OBDIII will be wireless - combine that with GPS and when you drive by a cop car he'll know exactly where and when your car went somewhere (and if you deserve a speeding ticket).

RE: Is electric powered transpo the answer?

The day they use GPS for speed monitoring is the day they get dismounted from my car and onto the wife's, or the kids bike or something. Or a fuse dropped out, a wire came loose etc.
All those guys busy unlocking phones will have a new career relabelling the GPS identifier as Paul McCatneys new car.

But, the cost of GPS for speed monitoring is next to nothing. The concept has been there since GPS became available.

Government's love investing millions on useless computer systems for ambulance management, doctors jobs, and so on and each and every time they get a cost over-run, a time over-run and the things don't actually work. They also love the idea of congenstion charging and toll roads with computer systems.

But on the off-chance they did get it to work then that government would be out of office quicker than anything.

Extreme solutions have a habit not only of not working but producing some unintended consequences.

JMW
www.ViscoAnalyser.com
 

RE: Is electric powered transpo the answer?

Oh yes, some bloke in the UK was convicted of dangerous driving when they examined the black box in his air bags and found out his speed (at impact when the air bags deployed) was way above the limit.
Now I don't know that too many people would object to some maniac being caught by the technology, but .......

JMW
www.ViscoAnalyser.com
 

RE: Is electric powered transpo the answer?

The ones to gain (as ever) would be the insurance companies: "Ah, I see your GPS wasn't functioning at the time of the accident.  That invalidates your insurance sir."

- Steve

RE: Is electric powered transpo the answer?

The answer then is simple, drive an old car without all the new features, or just add the ones you want.

The gas millage of older cars can be up to 30 MPG which is better than the new cars.

As far as electric cars, convert an old car for electric. t will cost much less than the newer electric cars, and it makes a nice project to work on with your son.

However, your second car probally should be a gas or diesel car for now for those longer trips.

 

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