Electric cars: What do you think?

Summary:

Are they really worth it?

Main Question or Discussion Point

I have been thinking about electric cars from an engineering point of view. I came to the conclusion that they are not worth it, for a number of reasons I will list below. What do you guys think?

1) Energy to charge the batteries must come from somewhere.
If the source of the energy is nuclear, fair enough, the energy source has no carbon footprint. But if the source of energy is from an gas/oil power plant, you are exchanging one fossil fuel engine for another one. The power plant is probably more efficient especially if it is a combined heat & power plant, but still.

2) Batteries age
Gas or diesel can sit happy in storage tanks for hundreds of years. Batteries age; any charge held in them is lost over time and furthermore, over time they lose their maximum charge level.

3) Safety of batteries
Batteries are basically sealed units with both the oxidizing + reducing agents mixed together in intimate contact. Which means the potential for a runaway reaction is there, waiting for a trigger. Gas or diesel tanks just contain fuel. Almost empty gas tanks contain fuel + oxidizer.

In any event, in an accident, the oxidizer for a gas/diesel powered car must come from the environment. For an electric vehicle, it is all there, pre- and well mixed. It will be very difficult to make the battery compartment of an electric vehicle immune to all sorts of damage which you might get in a conceivable lifetime - crushing damage, piercing, fires, etc.

4) Lifetime carbon footprint of producing batteries
Has anyone looked at whether the lifetime carbon footprint of mining lithium and producing the batteries is worth it?

IMHO the future fuel for cars is hydrogen.
 
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Answers and Replies

256bits
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How does hydrogen compare in your 4 points?
 
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1) To produce and store hydrogen also involves an energy investment.
2) Ageing of hydrogen storage - depends on how you store it. If in tanks, you will probably have a small % of leakage year on year, because hydrogen is such a small molecule. If stored as hydrides, the ageing will depend on the chemistry. Other storage methods will probably have their own losses as well.
3) Safety of hydrogen storage. Compressed H2 is explosive because of the pressurisation which would lead to rapid mixing with atmospheric oxygen upon container breach. Hydrides - depends again on chemistry.
4) Lifetime carbon footprint - if nuclear to electrolysis of water, then it is neutral.
 
russ_watters
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Summary: Are they really worth it?
I don't think their time is here yet, but it is coming in the next few decades. The basic issues I see are similar to what you said:
1. Electric cars are too expensive when measured fairly.
2. Not enough/too slow chargers/range issues.
3. Gas is too cheap.
4. Our power grid burns too much fossil fuel (though this does not affect consumer choices much).

As evidenced by the fact that hybrid car sales dropped significantly over the past few years, I don't think consumers will switch on their own, without a significant change in the landscape.
4) Lifetime carbon footprint of producing batteries
Has anyone looked at whether the lifetime carbon footprint of mining lithium and producing the batteries is worth it?
I'm not sure, but usually the question can be answered in large part by following the money: mining is fossil fuel intensive, so a significant fraction of the cost of mined minerals spent on fuel. A typical car will burn around 5,000 gal of gas over 10 years. A Tesla battery pack is around $5,000, so if half that cost is the energy needed to produce it (it's probably less), that would be about 1,700 gal at today's fuel prices.
 
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Link about assumed lifetime CO2 emission for different car types by country (EU only, see fig. 2 on page 6)

I would say it does not really cut it right now.
Based on Germany, I would say on wind alone it will never be able to cut it.
But I think it worth to keep around, since there are some country already where it is not just for show.
 
BWV
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Electric cars are a more efficient way to deliver energy to the wheels than internal combustion engines where most of the energy is lost through heat, this is the differentiator that more than makes up for issues with power generation and battery manufacturing.

Union of Concerned Scientists (Nealer, Reichmuth, and Anair, 2015) presented a comprehensive “well-to-wheels” analysis of the greenhouse-gas emissions from driving BEVs compared with those from gasoline-powered vehicles:

Energy source Fuel-economy equivalent (MPGghg)
Coal 29
Oil 29
Natural gas 58
Geothermal 310
Solar 350
Nuclear 2,300
Wind 2,500
Hydro 5,100

so an EV charging from 100% coal generated power has the same CO2 footprint as a 29MPG gasoline-powered car.

Rounding this https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
gives an approximate average US electricity generation mix of 30% coal (plus oil), 35% natgas, 20% nuke, 6.5% wind, 7% hydro, 1.5% solar, so (after fixing an error) an EV on average is equivalent to a gasoline car that gets roughly 60 MPG.


http://www.umich.edu/~umtriswt/PDF/SWT-2017-18.pdf
No one that I am aware of takes Hydrogen seriously as a solution for transportation anymore
 
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BWV
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All of the major automakers have now abandoned their H fuel cell programs and embraced EVs, the reason is simple - Hydrogen is a dumb idea:

The entire process of electrolysis, transportation, pumping and fuel-cell conversion would leave only about 20 to 25 percent of the original zerocarbon electricity to drive the motor. In a plug-in hybrid, the process of electricity transmission, charging an onboard battery and discharging that battery would leave 75 to 80 percent of the original electricity to drive the motor. Thus, a plug-in should be able to travel three to four times farther on a kilowatt-hour of renewable electricity than a hydrogen fuelcell vehicle could.
a pure EV is similar to a plug-in hybrid, it just lacks the internal gas generator

http://www.calcars.org/sci-am-romm-frank-apr06.pdf
 
russ_watters
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A couple of bits of caution there:
1. The second study doesn't include the battery manufacture, which is what the OP asked about.

2. Focusing on the energy mix may be misleading in that it doesn't necessarily accurately reflect the marginal impact on the grid of adding a bunch of cars. E.G, nuclear and hydro are fixed (at best) in the West. If you add a bunch of EV's, the power required to be added to the grid to supply them will come primarily from natural gas, and to a lesser extent wind and solar. I think in the US over the past few years it has been 2/3 or 3/4 natural gas. Though the upside for the US is a lot of that new capacity was replacing coal. Over the next few years though, a lot will replace nuclear, which takes us in the wrong direction.
 
BWV
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A couple of bits of caution there:
1. The second study doesn't include the battery manufacture, which is what the OP asked about.

2. Focusing on the energy mix may be misleading in that it doesn't necessarily accurately reflect the marginal impact on the grid of adding a bunch of cars. E.G, nuclear and hydro are fixed (at best) in the West. If you add a bunch of EV's, the power required to be added to the grid to supply them will come primarily from natural gas, and to a lesser extent wind and solar. I think in the US over the past few years it has been 2/3 or 3/4 natural gas. Though the upside for the US is a lot of that new capacity was replacing coal. Over the next few years though, a lot will replace nuclear, which takes us in the wrong direction.
Sure, the Union of Concerned Scientist numbers do include battery manufacture but the SciAM does not, but hard to believe it makes a dent in the 50 percentage point efficency differential

But as no new coal plants will be built and renewables are 40-50% of new capacity, it wont change the conclusion that EVs are more efficient and CO2-friendly than gasoline
 
russ_watters
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Sure, the Union of Concerned Scientist numbers do include battery manufacture but the SciAM does not...
Actually I was referring to the study linked by Rive. You didn't link the UCS study so I didn't read it.
...but hard to believe it makes a dent in the 50 percentage point efficency differential
In the study linked by Rive it accounts for about 10-30% of the lifetime emissions depending on the power mix.
...renewables are 40-50% of new capacity, it wont change the conclusion that EVs are more efficient and CO2-friendly than gasoline
Yes, I just want to make sure we answer the question asked and present an accurate picture.
 
russ_watters
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Energy source Fuel-economy equivalent (MPGghg)
Coal 29
Oil 29
Natural gas 58
Geothermal 310
Solar 350
Nuclear 2,300
Wind 2,500
Hydro 5,100

so an EV charging from 100% coal generated power has the same CO2 footprint as a 29MPG gasoline-powered car.

Rounding this https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
gives an approximate average US electricity generation mix of 30% coal (plus oil), 35% natgas, 20% nuke, 6.5% wind, 7% hydro, 1.5% solar, so an EV on average is equivalent to a gasoline car that gets roughly 1000 MPG
This math is wrong. It implies that a zero carbon source mixed in any proportion with any carbon producing source yields infinite fuel economy - it's because mpg is an upside-down unit you have to add like a fraction. You have to flip over the mpg to get a pound per mile(or whatever the actual unit is), then add them together, then flip it back over again. The answer is roughly 60 mpgghg, which puts it in line with the other sources.
 
BWV
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This math is wrong. It implies that a zero carbon source mixed in any proportion with any carbon producing source yields infinite fuel economy - it's because mpg is an upside-down unit you have to add like a fraction. You have to flip over the mpg to get a pound per mile(or whatever the actual unit is), then add them together, then flip it back over again. The answer is roughly 60 mpgghg, which puts it in line with the other sources.
OK, good catch.
 
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In the study linked by Rive it accounts for about 10-30% of the lifetime emissions depending on the power mix.
The energy mix part makes the whole picture quite a voodoo, actually. The very same car (or battery) manufactured/used on the Germany side of a border or on the France side, and the difference would make it green or not: like I would buy that...
It is good just enough to back up a 'not yet, but maybe it'll make it with time' opinion.
At least, by my humble opinion o0)
 
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Gas or diesel cars do not spontaneously catch fire like this.

Batteries already have the oxidizing and reducing agents pre-mixed and in intimate contact (by design). If cellphone batteries and cars can spontaneously catch fire without any apparent direct insult, imagine EV in accidents where the battery packs sustain direct damage. Even worse is if passengers get knocked unconscious due to the accident and then the car catches fire.
 
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Fires are an important point. If the next generation of batteries actually does deliver 2x or 4x the energy density of lithium batteries, the energy releases after malfunction or accident may be even more drastic.

Of course, gasoline and diesel fuels can explode when gasified, but we have more than 100 years experience handling them, and handling fuel fires.
 
OmCheeto
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Gas or diesel cars do not spontaneously catch fire like this.

...
Um..... Yes they do. All the cars in this video are gasoline powered. They recalled affected vehicles with defective PCV systems. I am not aware of any all electric vehicles with "crankcases".
 
BWV
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EVs currently are luxury goods, allowing consumers to signal both virtue and socio-economic status.

Not sure why plug-in hybrids are not more popular - I have been driving a Honda Clarity for about a year now and cant imagine either going back to gasoline-only or giving up the flexibility of being able to fill my 7 gallon tank if needed. I can do my daily commute on 100% battery, with 17kwh (about $1.35 of electricity charging at home) giving a 45 mile range (about equal to a gallon of gas). The electric drive train is a superior technology, with less moving parts and a smoother, quieter ride.
 
Um..... Yes they do. All the cars in this video are gasoline powered. They recalled affected vehicles with defective PCV systems. I am not aware of any all electric vehicles with "crankcases".
Gasoline powered only or hybrids that caught fire?

Some of the cars in the news clip are specifically described as cars not affected by the recall.

In any case if we talk chemistry here, if a gasoline/diesel only car spontaneously catches fire, there is a defective part and probably an unfortunate set of circumstances such as a near-empty tank. Gasoline or diesel by themselves don't burn without oxygen. A lithium battery will "burn" (or undergo thermal runaway) by itself without oxygen.
 
BWV
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Gasoline powered only or hybrids that caught fire?

Some of the cars in the news clip are specifically described as cars not affected by the recall.

In any case if we talk chemistry here, if a gasoline/diesel only car spontaneously catches fire, there is a defective part and probably an unfortunate set of circumstances such as a near-empty tank. Gasoline or diesel by themselves don't burn without oxygen. A lithium battery will "burn" (or undergo thermal runaway) by itself without oxygen.
Looks to be gas-only cars in this story

s.go.com/US/bmw-recalls-million-vehicles-fire-risk/story?id=50922136
 
OmCheeto
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Gasoline powered only or hybrids that caught fire?

Some of the cars in the news clip are specifically described as cars not affected by the recall.
The video is 2½ years old. My brief googling found that they've expanded the recall even this year.
 
JBA
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The above ignores two items relative to metropolitan (which is about 80% of our USA population) BEV usage.
First; there is the reduction of concentrated ICE pollution from commuters within those areas. The conversion from ICE to electric is a 100% reduction for every ICE vehicle replaced by a BEV. At the same time, the total energy consumption is also reduced by the higher efficiency BEV's, no more thousands of vehicles consuming energy while idling at intersections or parked on over crowded freeways.
Second, alternative energy sources are growing without the equal necessity for corresponding increased crude based pollution. For every additional amount of fuel required there is an additional amount of pollution and energy consumption associated with drilling and completing the required producing wells, crude transportation, refining of crude into usable fuels and and distribution of those fuels; none of which are required for alternative energy sources (I have intentionally not included the effects of distribution facility expansion because that is required in either case).

As to available BEV charging facilities, there are, at latest count, over 20,000 charging stations supplying 68,800 charging points across the US.

Additionally, I think the grid load issue maybe a bit overstated, (at least for the present) because the majority of BEV users have home chargers that are used during the low overnight peak power consumption period and with the current expansion of BEV mileages do not require any added daytime or evening additional charging.

Most importantly, converting to BEV's is also about dealing with the ever increasing amount of transportation and energy that is going to be required as our global population continues to expand exponentially. More energy demand is going to inevitably be required and the last thing this world needs is for crude to be the required or selected source.

As for any bias on my part, I spent my 40 year engineering career in the petroleum energy industry including involvement in its every stage, from E&C of international production and tanker loading facilities to crude well drilling and production to refining, so I am well aware of the issues associated with crude based energy.
 
russ_watters
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The energy mix part makes the whole picture quite a voodoo, actually. The very same car (or battery) manufactured/used on the Germany side of a border or on the France side, and the difference would make it green or not: like I would buy that...
It is good just enough to back up a 'not yet, but maybe it'll make it with time' opinion.
At least, by my humble opinion o0)
EVs currently are luxury goods, allowing consumers to signal both virtue and socio-economic status.
I was literally writing this before seeing those:

I read an op-ed recently, where the opinion was presented that focusing so heavily on individual carbon reduction is a bad thing (even calling it essentially a form of denialism, which is a bit much...). We carbon-shame the royals and rich people and virtue-signal with the buying of EVs, but these things are largely inconsequential or cart-before-the-horse.

So far essentially none of the carbon reduction effort has been shouldered by industry/government (with the minor exception of California), which is where almost all of it is needed. Even things like subsidizing EVs and residential rooftop solar are missing the mark. Without a clean grid, electric cars don't help much, so while it feels nice to encourage them, applying direct money to direct carbon reduction gives a much bigger bang for the buck, and avoids the problems on the backside that are currently ignored because they are inconsequential.

So I share your opinion and while I think it is nice to buy an electric car, I probably give the impression of downplaying it because compared to industrial carbon reduction because I do indeed think it is far less important and counterproductive if it serves as a delay/distraction. Yes, it's voodoo, and the question of whether I'd save 10% or 60% in carbon footprint by buying an electric car is just too complicated and indicative that it's not a great solution. By contrast if we replace a 1 GW, 90% capacity factor coal plant with a 1GW, 90% capacity factor nuclear plant, it is crystal clear how much we save.
 
russ_watters
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The above ignores two items relative to metropolitan (which is about 80% of our USA population) BEV usage.
First; there is the reduction of concentrated ICE pollution from commuters within those areas. The conversion from ICE to electric is a 100% reduction for every ICE vehicle replaced by a BEV.
I cringed a little at reading that, and I hope you didn't mean it to sound like you want to export pollution from cities to rural areas....which is of course how it already works.

I'm not sure I see a clear goal here except to make life better for people in cities by reducing in-city pollution. Isn't the larger goal to combat climate change?
At the same time, the total energy consumption is also reduced by the higher efficiency BEV's, no more thousands of vehicles consuming energy while idling at intersections or parked on over crowded freeways.
Yes, that's a viable goal, but almost all of it can be achieved with a hybrid car. EVs may be a nice to have there, but their benefit vs a hybrid is pretty insignificant.
Additionally, I think the grid load issue maybe a bit overstated, (at least for the present) because the majority of BEV users have home chargers that are used during the low overnight peak power consumption period and with the current expansion of BEV mileages do not require any added daytime or evening additional charging.
Well, sure, the downsides of an insignificant thing tend to be insignificant. But isn't the goal here to make the impact of EVs significant? If that's the case, then you have to take the significant downside along with the significant upside -- you can't have one without the other. Converting a significant fraction of cars to EVs without increasing pollution will require a significant increase in the number of power plants capable of providing clean energy, with flexibility to provide a significant amount of it day or night, in good weather or bad.

Many municipalities in California are aiming to go a step further by banning natural gas for new construction, with the eventual goal of phasing it out (it will take maybe 30 years). If that happens, then the grid will peak at night, during the winter, maximizing the collective downsides of EVs and intermittent renewable energy. That's a big, big problem that they are planning to cause, with no plan to solve it. Then we'll be arguing if 3.0 COP heat pumps powered by natural 45% efficient natural gas power plants are better or worse than 95% efficient natural gas furnaces and nothing will have actually changed emissions-wise.

That's why it is so important to address the grid first.
 
Here's why I have problems believing any car that spontaneously starts burning when off are not 100% gas or diesel powered (not hybrids):

1) Gas or diesel tanks by themselves don't burn. If you puncture them, they are semi-empty and bring an ignition source to them, gas will burn easily but diesel with great difficulty.
2) If either start burning with insufficient air, you get a (yellow - if you can see it) sooty flame. Such flames are usually not seen in spontaneous burning of vehicle videos, until after other components like interiors have started burning.
3) If your car is only gas or diesel powered, and shut off, and something with aerated fuel catches fire - how does more fuel get conveyed to the burning site? Capillary action? Is a pump still running? Why is the pump still running when the car is off?
4) If you get thermal runaway in a lithium battery, you get white smoke first and then (maybe) flames.
5) Many of the "burning" events you see in the linked video, and others on Youtube begin with white smoke being produced, and then a fire.
6) The flame test for lithium is red. In some videos of e-bikes/cars spontaneously burning you even see that the flames have a reddish hue.
7) What is the ignition source? If the car has just been turned off then maybe a hot engine (if it is a gas/diesel only-powered car spontaneously catching fire). But some of the cars had been off for some time. In which case the ignition source can only be electrical.

IMV I cannot reconcile the above line of thinking with cars spontaneously catching fire while off for some time. For a gas/diesel only-powered car to spontaneously catch fire, there are a number of factors which must be met:
1) Oxygenation of the fuel
2a) Initial transport of fuel to the burning site
2b) Continuous transport of the fuel to the burning site, while it is burning
3) Ignition of the fuel/air mixture

OTOH for an e-vehicle or hybrids' battery pack to catch fire, you only need a short circuit, e.g. physical damage to the battery causing an internal short circuit, an external one that bypasses any overcurrent protection system, etc.
 
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Not sure why plug-in hybrids are not more popular
I too tend to wonder on that, and the best answer I could come up was, that it is seen as a compromise, so it is just not accepted as declaration of greenness: while on the other side it is seen as a traitor.

Would be nice to nice to see a bunch of PHEVs, powered from a 80% CO2 neutral grid and backed up with 50% renewable fuel (recovered from bio- and plastic waste or byproducts).
Such sweet dreams...

I read an op-ed recently, where the opinion was presented that focusing so heavily on individual carbon reduction is a bad thing (even calling it essentially a form of denialism, which is a bit much...).
I do not think that individual carbon reduction/awareness is a bad thing in itself, but it indeed has a part what makes the notion vulnerable to hijacking (just as it works for any ideal at the point when it becomes a public movement with a people to direct it). I still struggle to understand the whole 'save the planet' thing - not ruining it seems to be far more effective, no? Like that waste-gathering from the oceans with all that effort and so.

EVs may be a nice to have there, but their benefit vs a hybrid is pretty insignificant.
Link, fig. 6. around 3/4 of the page

If that happens, then the grid will peak at night, during the winter, maximizing the collective downsides of EVs and intermittent renewable energy.
Correct. And with that, all the benefit what could come with PV, will be thrown away too.

Then we'll be arguing if 3.0 COP heat pumps powered by natural 45% efficient natural gas power plants are better or worse than 95% efficient natural gas furnaces and nothing will have actually changed emissions-wise.
Still prefer to power the heat pump with a simple, 35% efficient gas engine and add all the waste heat to the COP o0)
 

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