Electric Cars

[abc]

can someone explain to me how electric cars are more fuel efficient when they weigh more per cubic metre?

[Nort]

can someone explain to me how electric cars are more fuel efficient when they weigh more per cubic metre?

What do you mean by fuel efficient? Amount of petroleum burned? Energy used to get up to speed? Energy used per KM? Cost of the energy used for a particular journey?

[abc]

can someone explain to me how electric cars are more fuel efficient when they weigh more per cubic metre?

What do you mean by fuel efficient? Amount of petroleum burned? Energy used to get up to speed? Energy used per KM? Cost of the energy used for a particular journey?

energy required to go from point A to point B

[bits]

ICE all you want is the explosion pushing the piston, any energy wasted on heat, noise, pumps, cooling etc is lost. You may redirect some of that heat to the cabin for passenger comfort but that is a very small perk.

So ICE is apparently only about 20% efficient for the energy it consumes. Most of the energy is lost to heat in particular.

EV is about 87-91% efficient.

Source https://witricity.com/newsroom/blog/ev- ... fferences/


But also it is important the source of the energy.
EV can get its energy from different sources than available to fossil fuels.

[rev]

ICE all you want is the explosion pushing the piston, any energy wasted on heat, noise, pumps, cooling etc is lost. You may redirect some of that heat to the cabin for passenger comfort but that is a very small perk.

So ICE is apparently only about 20% efficient for the energy it consumes. Most of the energy is lost to heat in particular.

EV is about 87-91% efficient.

Source https://witricity.com/newsroom/blog/ev- ... fferences/


But also it is important the source of the energy.

I think a question just as important, is how much energy/resources/waste/etc is needed to produce each type of vehicle, from top to bottom, including the batteries for EV's.
What that then raises is what is the cost in those terms, environmental etc, to replace an EV's battery, or is it financially not worth it therefore a new EV is required and the old one scrapped.

EV can get its energy from different sources than available to fossil fuels.

You mean like the charging stations that are running on diesel generators?


Elon Musk has some interesting thoughts I believe, definitely from what I've heard/read he has a much more practical, sensible and logical approach to the whole matter as opposed to those in society who are hanging them selves bridges and blocking traffic or attacking the offices of energy companies.

[Nathan]

Elon Musk has some interesting thoughts I believe

That's definitely one way of putting it.

[bits]

You mean like the charging stations that are running on diesel generators?

I am sure there are examples of that. Even SA grid at times has diesel burning. But 0.06% in the last 25 years doesn't seem like it is a particularly serious concern.
0.09% in the last year while 70% of the SA grid power came from wind or solar. 30% came from gas or interstate which itself is a mixture of brown/black coal, gas, wind, solar etc.

EV cars can and do use wind and solar electricity, ICE cars cannot. How much wind and solar goes in can vary but the more wind and solar the cheaper the recharge will be.
Customers want to charge from their own solar/battery and/or the solar sponge time of 10am-3pm to get the best savings. Where that isn't possible they are at the mercy of the grid which in SA is heavily and ever increasing wind and solar.

Being able to find the worst case doesn't mean it is always the worst case.
Nor is that worst case certain to remain.
If a country town or rural homes sole electricity source is diesel generators, then EV probably isn't that great an idea yet.

[bits]

Also worth noting that public charging stations are likely a worst case scenario for the average EV owners.

You likely would much prefer to charge at home or work because it is more convenient and cheaper.

The reason ICE cars go to a for profit commerical petrol station is because you can't easily make the fuel at home or at work. If you had cheap and easy access to fuel at home or work, you would just do it there.

[abc]

ICE all you want is the explosion pushing the piston, any energy wasted on heat, noise, pumps, cooling etc is lost. You may redirect some of that heat to the cabin for passenger comfort but that is a very small perk.

So ICE is apparently only about 20% efficient for the energy it consumes. Most of the energy is lost to heat in particular.

EV is about 87-91% efficient.

Source https://witricity.com/newsroom/blog/ev- ... fferences/


But also it is important the source of the energy.
EV can get its energy from different sources than available to fossil fuels.

this doesn't answer my question, not even close

87-91% efficient sounds like a factoid not a fact

[bits]

You asked why and I answered why.
ICE wastes most of its energy on heat which does not move the car. It is a furnace on wheels where 80% of the energy is converted in to heat.
EV has to lug a heavy battery around but that doesn't cost more than the losses ICE has. Also that mass inertia I am sure then get used in regenerative braking giving back a little it took.

What do you want?
Examples numbers are:
EV - 38 megajoules per 100 km
ICE - 142 megajoules per 100 km


https://www.theguardian.com/football/ng ... ctric-cars

[rev]

You mean like the charging stations that are running on diesel generators?

I am sure there are examples of that. Even SA grid at times has diesel burning. But 0.06% in the last 25 years doesn't seem like it is a particularly serious concern.
0.09% in the last year while 70% of the SA grid power came from wind or solar. 30% came from gas or interstate which itself is a mixture of brown/black coal, gas, wind, solar etc.

EV cars can and do use wind and solar electricity, ICE cars cannot. How much wind and solar goes in can vary but the more wind and solar the cheaper the recharge will be.
Customers want to charge from their own solar/battery and/or the solar sponge time of 10am-3pm to get the best savings. Where that isn't possible they are at the mercy of the grid which in SA is heavily and ever increasing wind and solar.

Being able to find the worst case doesn't mean it is always the worst case.
Nor is that worst case certain to remain.
If a country town or rural homes sole electricity source is diesel generators, then EV probably isn't that great an idea yet.

This is specifically what I meant. The diesel generator is a backup. Elon Musk said recently that diesel and oil shouldn't be demonized in the mid term.
The aim should be to gradually move to fully sustainable sources, not a major rush where we trip over each other without thinking. As this diesel backed EV charging station demonstrates, we still have a long way to go.



What's planned is pretty much highway 1. And this is just the NRMA (SGIC).



As for charging them at home, the big obstacle there at the moment is the up front cost to get solar & a battery setup. You're looking at $20k~, not to mention the cost of the EV.
Buy an ICE vehicle, that's big up front cost.

[bits]

The guardian article I linked includes these words which is news to me. They include links to their sources.

"An EU study based on expected performance in 2020 found that an electric car using electricity generated solely by an oil-fired power station would use only two-thirds of the energy of a petrol car travelling the same distance."

So apparently if you charge an EV from 100% diesel generator you are still using less fuel than ICE.
This will be because a diesel generator is not as inefficient as the ICE car.
I am sure studies like the below were not based on 100% diesel generators and other factors will be worse for it.
I would still go with, don't use EV if you only have diesel generators. Unless you are a for profit company and can make a profit doing so.


"A report by the Ricardo consultancy estimated that production of an average petrol car will involve emissions amounting to the equivalent of 5.6 tonnes of CO2, while for an average electric car, the figure is 8.8tonnes. Of that, nearly half is incurred in producing the battery. Despite this, the same report estimated that over its whole lifecycle, the electric car would still be responsible for 80% of the emissions of the petrol car. "

[abc]

F = MA

EVs have much higher mass

as you were

[bits]

It has been explained.
If you know the science that disproves this explain it. I am no scientist perhaps you can school me.
However your post of F=MA seems very lacking and I lean to that you are simply still confused.
It seems you are confused with the energy spent to create the A vs the resulting output F.

EV's are not an ICE vehicle with a battery.
These 2 types of vehicles are carrying potential energy stored in different forms. How the energy is released is via different methods. How that energy is converted to torque is different.
Those differences are why one requires more energy than the other in regards to conversion of energy into torque/rotation force.

During the ICE conversion of energy to torque there are substantially higher losses to heat. The user rapidly changing rpm and needing gear ratios that can allow high torque at very short notice further increases the losses in the system.
Diesel generators with more predictable loads, slower changes in rpm, longer periods at ideal gear ratios and potential secondary capture and reuse of heat makes them more efficient.

EV is not an explosion in a box pushing piston/crank/transmission etc.
It is electricity creating magnetic fields.
EV is not ICE.

If you are still struggling perhaps consider a pot of water that you want to heat up.
You could heat it up via multiple different methods. A small wood fire, a microwave or a laser. There are so many options.
The resulting heat you put into the water can be the same, eg you heated it up 20C. That is a fixed amount of energy right?
That doesn't mean you spent the same amount of energy to get that increase. You may have burned down a forest to heat that pot of water. Maybe you only burned a house. Maybe you put it in the microwave for 15 seconds.
The energy in you spent is not directly linked to the energy out you wanted because energy was lost during the conversion to things that were not heating that particular pot of water. There are different losses.

[Nathan]

Speaking of wasting energy, don't spend yours here. abc is not interested in arguing in good faith.