Electric Car Debate

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dereckbc

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Plano, TX
OK, so this doesn?t have anything to do with the NEC, but another thread about DC motors and a heated debate between my Fathers-in-law got me thinking about it. Basically I take the stance a true electric car will never be practical unless there is a major leap, and I do mean a major leap in battery technology.

So here is the debate: What do you think it would take to make an electric car practical to replace an internal combustion engine. I have my list of objectives, and by today?s technology, it is not possible now or in the foreseeable future

Top speed: At least 90-mph
Range: 300 to 400 miles on a single charge.
Passengers: at least 4 with reasonable cargo capacity like a trunk.
Size: At least a compact on the lines of a Honda Civic.
Fuel cost per mile: Comparable to gas assuming $2.50 per gallon @ 20 MPG or $.125 per mile.

I won?t give all my thoughts away just yet, but if you crunch some numbers, see what you come up with and see if you think it is even remotely possible. Here is a short list of things to consider.
Horsepower to KW. My Honda Civic has a 4-cylinder 140-hp engine
Weight of the vehicle including the fuel source
Cost of electricity. Hint I used $.13 per KWH.
Battery capacity needed.
Weight of the batteries, use any technology you want. Hint; Lithium Ion has the highest density ratio.

So if you have nothing better to do, give it a try, and post back with your thoughts. Have fun, and keep it friendly and on subject. No politics, tree-hugers, or religion allowed in discussion.

Dereck
 

tallgirl

Senior Member
Location
Great White North
Occupation
Controls Systems firmware engineer
Some of your requirements, particularly horsepower, are off base. Internal combustion engines and electric motors aren't comparable when it comes to the exciting world of torque. And with internal combustion engines, torque is all about acceleration, not highway cruising.

So, you can get an electric motor which makes big, fat torque numbers at low RPMs (and remember that torque and horsepower are mathematically related by RPMs -- Torque x RPMs / 5252 = HP) where a gasoline engine is either stalled or struggling to overcome internal friction, but won't make the same horsepower, and still have a very peppy little car.

Top speed -- the last time I drove 90MPH was weeks ago. Acceleration is more important than (illegal) top speed, and as I showed a second ago, electric motors can get off the line just fine without all that horsepower.

Passengers -- how often do you have four of them? Or a trunk full of prized possessions? And how many miles do you drive with four of them? And a full trunk?

Range -- how often do you drive 300 miles in a day?

I think it will take a paradigm shift in car buyer's minds so that they consider owning as much car as they need most of the time, rather than as much car as they might need for impressing the neighbors or driving cross-country. I also think it will take a change in insurance laws so that DRIVERS are insured and not CARS. I own two cars and I pay more for insurance than a lot of drivers with far worse records -- because I'm paying twice as much as I should given that I can only drive one car at a time. Lastly, I think people will have to consider having commutermobiles for commutering and a family car for those rare occasions when the car is loaded to the gills with people and stuff.
 

Bob NH

Senior Member
People all over Sun City, AZ drive electric golf carts all over town and are happy with them. The point is to find a vehicle that will fit most of the needs, and then to find another way to meet occasional other needs.

I occasionally make long trips of as many as 800 miles in a day and a trip average of 300 miles per day. I am better off renting a car than owning one that I want to take on that trip.

A small electric car that is targeted for local use (maybe 100 miles round trip) would cover 95% of days that I need a car.

A large number of electric cars would require a lot more electric power generation. The only environmentally friendly and economical solution is nuclear power. Wind and solar exist only because we subsidize them with our taxes. And nuclear would help our balance of payments because the greatest cost is the labor to build the plants. It is hard to import that from China or India.

The real joke is the push for fuel cell cars using hydrogen. When you look at the cost of making and delivering hydrogen, and the thermodynamic losses in the process, it will never be competitive with other sources of storing energy. Some day people will realize that hydrogen is not a SOURCE of energy.

On the fuel side of things, the joke on the public is ethanol from corn. It also exists only because of government (congressional) fiat and subsidy. They give buyers a subsidy for buying E-85 vehicles that will burn 85% ethanol, and there are hardly any places that sell 85% ethanol. And no person in their right mind would buy 85% ethanol unless it costs at least 25% less than gasoline. It contains less energy and costs as much as gasoline. Mileage tests have confirmed that it is a real dog for fuel economy.

Ethanol will not be a viable fuel without subsidies until the farmers who grow the corn start using unsubsidized ethanol instead of diesel fuel.

All of the subsidies and forced fuel regulations are a tax as much as the income tax. People just don't realize it.
 

e57

Senior Member
Popping back in on this one.... Heres my wish list.

I want an Electric Full-sized van.... a 3/4 ton... :cool:
  • 2400w inverter for the microwave... (Lunch)
  • Boomin system - Gheto style bass...
  • Alarm/gps and video monitoring all 'round
  • shelves and racks - work stuff - gang-box - All chrome,,,
  • White with 'lectric blue racing stripes (Shelby style)
  • And a giant garage to put it in...
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
There are a few more requirements to add:

A heater that works without killing the range.
An air conditioner that works without killing the range.
And for some, a killer stereo that works without killing the range.

I agree that it needs to be able to carry 4 people and the occasional load of conduit, pipe, or 2x4's from the home center. Even if you don't do it every day, if you only need it a few times what do you do, especially if you can't plan in advance? This is the same reason I have a truck -- I need something to pull a heavy trailer with, but you pay for that all the time by having a heavy overpowered 4WD vehicle. I don't drive that vehicle as much because I can afford two, but it must be driven occasionally to keep it from deteriorating.

As others touched on, changing the way insurance and license plate costs work would be required to allow people to own a second smaller less capable vehicle. I'd definitely consider a small electric-only car with 80mi range if the recurring costs were greatly reduced.

To me, the hybrid technology seems an almost ideal compromise. The engine can be sized for the average power needs instead of maximum. An engine is a source of heat (if needed) and may not be a bad way to support the air conditioning and power for other accessories (steering, brakes, 12 VDC stuff). Not all of the produced electricity from the engine-generator needs to suffer through battery losses -- it can be used directly when it is needed.

I also agree, hydrogen and corn/alcohol are a joke. Perhaps we need better science education so the masses could tell the politicians to stop taking the corn and hydrogen bribe money and support more realistic research and solutions.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
12VDC systems are totally inadequate for the purpose, it is why the IEEE came up with a 48VDC vehicle system.

I don't see it being practical until someone can come up with a motor/drive combination for each of either 2 or 4 wheels. The electronics is not quite there but is close.

That way you get rid of the transmission and engine altogether. The brakes can be mostly eliminated by using motor regen, possibly with a mechanical brake used very sparingly for cases where the motor can't take all the energy, or in case of motor/drive failure. Does not have to work but once, so can be cheap. Would get rid of the separate ABS as well.

Will need fly-by-wire technology, which is readily available.

This technology is necessary to make electric cars practical regardless of the way the electricity is generated or stored.

I think the answer for heat is an auxiliary system powered by gasoline or diesel, or maybe LNG/propane, something like a small furnace. A/C could be handled the same way.

The real kicker is range and refueling time. Few people are going to accept a car that has such a limited range or long refueling time that it is impractical. One might argue about whether it needs to go 90 mph or not, but realistically, it needs to go as fast as the fastest speed limits with some headroom, and that is about 90 mph. it needs to refuel in maybe 5 minutes - that is the toughest part.

I agree that ethanol or hydrogen has limited potential, although fuel cells are almost there.

I think the technology for everything is there today except the battery. lead acid batteries are not the answer, and I am not convinced Li-ion is either. The biggest roadblock is recharge time. No battery technology has fast enough recharge time to be practical as of yet.

IMO, the best answer we have is NG. We already know how to handle it safely, and existing engines can be readily modified to burn it, and it is essentially non-polluting (unless you believe the CO2=global warming nonsense). It suffers from a single problem though that stops government from pushing it - how do you tax it???? It is already available in most peoples homes and they are not going to pay road taxes voluntarily for the NG coming off the same line that feeds their furnace.
 

bob

Senior Member
Location
Alabama
Bob NH said:
A large number of electric cars would require a lot more electric power generation. The only environmentally friendly and economical solution is nuclear power. Wind and solar exist only because we subsidize them with our taxes. And nuclear would help our balance of payments because the greatest cost is the labor to build the plants. It is hard to import that from China or India.
Most electric Utilities have a surplus of power at night that they would like to sell. A major shift to electric vehicles would be welcomed by the Electric Suppliers.
 

dereckbc

Moderator
Staff member
Location
Plano, TX
I knew this would get interesting and here are a few replies to various posters.

Robbie,
You stole some of my thunder. I am an advocate for bio-diesel; UK, Japan, and Germany are way ahead of the US as it is a major fuel supplement and/or replacement. Sad US auto manufactures do not offer diesel vehicles for the US market, and the ones they do offer use incompatible fuel delivery systems to allow bio-diesel fuels. FWIW it will not be WVO, not enough Taco Bells to go around; it will be something like palm or rape seed oil.

Julie,
I respect your opinion, but I disagree. It is true horsepower can be lower in electric motors, but you have to pick something because everything else depends on some sort of rating. Perhaps I should have used Kilo-Watts. So an equivalent 100-hp engine equates to a 75 KW electric motor. Point is you have to pick something because battery weight is crucial when an distance is required.

Passengers, speed, and cargo are especially important IMO if we are going to replace the internal combustion engine. The US market, soccer moms, etc are not going to buy into the idea of a Frenchie cracker box sized vehicle. Everyday task include shopping, highway travel with the ability to pass, and occasional trips are required to make it doable. Otherwise you are just talking a very limited niche market.

Bob NH,
Sun City residents is extremely niche, and golf carts are governed to 12-mph by law. Sorry not practical IMO. However I do agree with your assessment on Ethanol, and if we do go electric, the US is going to have to go nuclear in a big hurry to meet the demand, no way around it.

Roger,
Thanks for laugh. I have been to the website many times. Somehow I don’t think a we are talking about a drag-car with a max range of 10-miles in 3-minutes. Oops there is bedroom joke in there somewhere :)

Petersonna,
Most BEV (battery electric vehicles) operates at voltages of 160 to 500 volts. Newer generation BEV’s use a standard of 300 VDC and an inverter to convert the DC to 3-phase AC to drive the motors. You can toss 48-VDC out the window unless you are talking forklifts. Think about the current that would be needed at 48VDC to supply a 50 to 200 KW motor.

Bob,
While it is true today POCO’s have excess generation at night, that would fall way short if we convert to electric vehicles. We would have to have a mass build out or generation plants to supply the demand. Nuclear would be the only feasible way, and with the “NOT IN MT BACKYARD”mentality is a huge obstacle to overcome. Fossil fuel plants cannot do it.

All,
Today the motor, controls, and electronic technology already exist and are in place to make it happen. However battery technology, electrical generation, home delivery, and feasibility are decades away.

Even if you use the smallest of motors of say 36KW, you have to limit mileage to around 50 or so miles because of battery size and weight. The battery weight to supply a 36 KW motor by today’s technology is 1100 pounds @ 50-mile range. To get a range of say 300 pounds require 6600 pounds of batteries, and larger/heavier vehicle to hold the batteries. If you did that, then you need larger motors, which lead to larger batteries, which lead to an impenetrable wall of mass, weight, and power requirements. Now to another problem. How many homes are capable of delivering 100 to 300 KWH of power in a few hours to recharge? Who is willing to replace batteries every couple of years at enormous cost.

Just some food for thought.

Edited to correct some grammar.
 
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Bob NH

Senior Member
rr said:
Diesel. Specifically running with WVO. (Waste Vegetable Oil)

I win. :)
Using waste vegetable oil for diesel fuel is largely a symbolic gesture. If you think we have a fuel shortage now, just try to buy waste vegetable oil for all of the diesel engine vehicles in the US.

Up here in the Northeast where we use #2 fuel oil (same as diesel) for heating, the best way to use the BTUs in waste vegetable oil is to mix it in your oil tank. Up to about 3% in the tank is burned without any problem. The only processing required is to get the scraps of French fries and fish batter out of it. Small amounts of rendered animal fats (such as bacon grease and chicken fat) can also be used. The oil will dissolve it.
 

rr

Member
Location
Georgia
Bob NH said:
Using waste vegetable oil for diesel fuel is largely a symbolic gesture. If you think we have a fuel shortage now, just try to buy waste vegetable oil for all of the diesel engine vehicles in the US.
While it might be a symbolic gesture now, would it be if it caught on? Would folks realize that real WVO fuel can be used for pennies on the dollar compared to conventional fuel sources?

The new "common rail" diesels are still too new to determine if WVO will eventually harm them. There are people who are running WVO in these newer motors with no problems so far. I know the older VW and Mercedes diesels have racked up thousands of miles with WVO.

There are plenty of eating establishments that would provide the oil for free (They have to pay a fee to haul it away). I know http://www.greasecar.com has a mobile and stationary filtration unit to aquire WVO.

I mean who WOULDN'T want a car that smelled like french fries? :)
 
Well I live off grid and have a 35 mile round trip to go to work. I’m running a 48 volt system witch is 99% hydro; I’m make 60,000 watts a day off my hydro and about 11,500 off a good sunny day. With my inverters I have 60 amps (240) that I can use. Currently I’m only using 50,000 watts a day in power. Because there are no power lines where I live I can’t net meter, so I dump 20,000 watts a day.

I would love a golf cart if it would do 55 and run 100 miles between charges. I’m in my car for less than 10 minutes at a time so why have all the bells and whistles. A cheap CD deck and 2 6by9’s and I would be good to go.

Why not go back to the 2 meter system and use the “night meter” for charging your car. I have read about some companies in CA that only pull off the grid at night to charge a battery bank and PV and batteries to get through the day. I think there using the Vanadium technology.


**edit**
Thank you Bob, your right. I forgot witch form I was posting on.
Watt-hours are what I was meaning to say.
 
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Bob NH

Senior Member
got_nailed said:
Well I live off grid and have a 35 mile round trip to go to work. I?m running a 48 volt system witch is 99% hydro; I?m make 60,000 watts a day off my hydro and about 11,500 off a good sunny day. With my inverters I have 60 amps (240) that I can use. Currently I?m only using 50,000 watts a day in power. Because there are no power lines where I live I can?t net meter, so I dump 20,000 watts a day.
Could you clarify the units. Watts a day isn't a unit of energy. Is it Watt-hours per day?
 

tallgirl

Senior Member
Location
Great White North
Occupation
Controls Systems firmware engineer
dereckbc said:
Julie,
I respect your opinion, but I disagree. It is true horsepower can be lower in electric motors, but you have to pick something because everything else depends on some sort of rating. Perhaps I should have used Kilo-Watts. So an equivalent 100-hp engine equates to a 75 KW electric motor. Point is you have to pick something because battery weight is crucial when an distance is required.

Passengers, speed, and cargo are especially important IMO if we are going to replace the internal combustion engine. The US market, soccer moms, etc are not going to buy into the idea of a Frenchie cracker box sized vehicle. Everyday task include shopping, highway travel with the ability to pass, and occasional trips are required to make it doable. Otherwise you are just talking a very limited niche market.

Second paragraph first -- that's why I said a paradigm shift is needed. You're absolutely right -- no one is going to buy a commutermobile for their primary transportation, where "commutermobile" is defined as "only useful for driving to and from the office". Ain't going to happen.

Now for the first paragraph -- the reason horsepower in electric motors is so different is because they make torque at 0 RPMs and because they can be made to avoid all the driveline losses that go with gasoline.

The 5.7L motor in my 'vette makes about 365HP and 385 ft-lbs torque at the flywheel. Or at least GM says it does. By the time it makes it to the back wheels it's down to 260HP according to the dyno I had it plunked down on. And a LOT of that horsepower is because ... gasoline engines don't make torque at 0 RPMs.

If you can hookup the wheels of an electric car, they take off like a dragster if they have comparable horsepower to a gasoline powered car. They just do -- absolutely insane acceleration. And if you maintain the same torque on your gasoline powered car to get a reasonable launch, you'll soon find yourself violating the speed limit. Torque, which is what really matters (torque wins races, horsepower sells cars), is very different between the two types of motors. It's not commonly known, but the reason electric traction motors are used for locomotives is because diesels don't work in that application. The diesels are great for generating the electricity, but it's the electric motor that gets the job done.
 

drg

Senior Member
Bob NH said:
Using waste vegetable oil for diesel fuel is largely a symbolic gesture. If you think we have a fuel shortage now, just try to buy waste vegetable oil for all of the diesel engine vehicles in the US.

Up here in the Northeast where we use #2 fuel oil (same as diesel) for heating, the best way to use the BTUs in waste vegetable oil is to mix it in your oil tank. Up to about 3% in the tank is burned without any problem. The only processing required is to get the scraps of French fries and fish batter out of it. Small amounts of rendered animal fats (such as bacon grease and chicken fat) can also be used. The oil will dissolve it.

We use #2 here also for the same reasons as you , and we also power equipment with #2 in the warmer months. I like the thought of using WVO as a blend and I am sure willing to try , Looks like a filtering system will be required though .
Do you think there is anything you can do with waste motor oil along the same lines ???? We have barrels that need to be put to use , and can you incorparate this in with #2 also ? Assuming its has been filtered and mixed in at a low percentage with the #2 .
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
tallgirl said:
It's not commonly known, but the reason electric traction motors are used for locomotives is because diesels don't work in that application.
Yeah. Pressing that clutch pedal would be killer! :wink:
 
I drove a CNG full size van a few times. It didn?t have much range and zero degrees was a problem.

Never drove an electric car but my old boss did and I saw that it didn?t have any range and zero degrees made it all but useless. So I agree batteries need a miraculous breakthrough.

Could someone expound on the problems with the hydrogen fuel cell? I would have thought that was the only realistic option for electric cars.

Wish I could say ethanol was a joke?but considering the money that it is costing the consumer, it isn?t funny.
 
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