Tesla Model S, Third Fire

[mamalala]

sorry - my bad - it was 3 x 16's amps when I left europe 10 years ago - for small 3bd villa's plus a single 380v. In our UK 3 bd villa we have 4 phases - no 380v - but gas stove.

Hmm, that doesn't make sense (at least as far as Germany is concerned, but i guess for most of Europe as well): over here, 3 phase power gives you 230V between any phase an neutral, and 400V between any two phases (used to be 220V and 380V).

There are very old installations that have lesser power capacity, but those are mostly modernized nowdays, so it would be rare to see such an installation nowdays. And if, they are mostly in very old appartement buildings with multiple flats per building.

And how is 4 phase supposed to be delivered? My guess is that what you had was really single phase and then just split up into different circuits, or a two phase supply split up to give 4 circuits. Never saw any real 4 phase supply in any installation, heck, even the grids are 3 phase only.

Greetings,

Chris

[dr.diesel]

Not an in-depth comparison, but since I'm in the power industry I'll make a quick post concerning available generation.

Already here in the Midwest, just this past summer (July and August are the big hitters) for example, we end up running our (4) 3MW diesel (20 cylinder GM 2-stoke) generators to maintain voltage levels in our area.

Duke/Progress energy (largest US utility) is closing several GWs of generation in the next few years due to the increased environmental mandates.  Some of these plants are actually already shutdown.

I agree with Corp, this problem is not a show stopper as the uptake in EVs is pretty slow, but be must be careful by closely monitoring making accurate predictions of the future.  A new Coal/Combine gas plant if agreed on today would take 5-7 years to hit line, nuclear would take 10-15.  GM/Ford/Toyota bringing a $30k no frills EV to marked with 300+ mile range before we are ready could crush the grid in certain areas in hot summer months.

[dr.diesel]

Because refining petrol to drive one mile in a typical ICE car uses more energy than a typical EV requires to drive one mile electricity consumption will actually fall when we change over.

That's why electricity companies are no desperate to get more EVs on the road, and why there will be no crisis due to a rapid change over.

Interesting, I've not read any evidence to support that, not discrediting you, just not seen it.  Have a study for me to read up on?

However, as EVs grow and the demand on dino fuel eases, prices will go down and the more fuel is burned.  Now you have the lots of refining and lots of electrical load via EVs.

[NiHaoMike]

However, as EVs grow and the demand on dino fuel eases, prices will go down and the more fuel is burned.  Now you have the lots of refining and lots of electrical load via EVs.

Increase gasoline taxes to keep prices about the same.

[dr.diesel]

Increase gasoline taxes to keep prices about the same.

Hey, double bonus, they could fund ObamaCare.

I'd prefer the government do something intelligent for a change.

[zapta]

Increase gasoline taxes to keep prices about the same.

Taking more of people' money, the socialist ideal.

[Rufus]

Well back then it was mostly lead acid batteries, so around 400:1. So not practical beyond about 30 miles.
Nowadays it is less than 50:1 so the engineering solution is to put a massive battery in the vehicle.

Back then IC engine efficiency would also be rather crap evening it out a bit.

Again, from an engineering perspective, what is wrong with putting a large battery in a vehicle, if it works well, like in the Tesla's case?

Massive batteries are massively expensive and heavy and wear out. Tesla have to make something like 40% of the weight of the car batteries to get moderately acceptable range. Lugging 1500lb of battery around with you doesn't help make it an efficient car does it?

It is expensive, doesn't perform that well unless you are close to home and free of range angst, marginally green at best until electricity generation is more green so what is the point?

And that is a car, what are trucks that want to drive 8 hours a day going to do? will a 40 ton truck carrying 10 tons of battery be practical or affordable? Ships need to run for days, are we going to have ships with thousands of tons of batteries? We are not going to be flying anywhere on batteries either.

Batteries can't compete with the energy storage density of chemical fuels - not even close and I don't believe they ever will. Supply of dead dino chemical fuel is limited so we need to be synthesizing our own. Nuke aircraft carriers already synthesize aviation fuel to avoid the cost of carrying it around or having it delivered - it is possible - you hear hardly anything about it so I don't know how efficient or practical it
currently is.

It would be a good use of intermittent solar and wind generation and the capacity of nukes when demand is low, you could probably combine it with (likely silly) CO2 sequestration schemes.

To me storing the intermittent energy from renewable generation in high density chemical fuels makes a lot of sense because they are so valuable for portable energy requirements. Unless there is some very significant break through in battery or fuel cell technology I predict that is the way the world will eventually go and that EVs will be seen as a technological dead end that a lot of money and effort was wasted on.

I don't see bio fuels doing much except as a bi-product. Too much energy is required to harvest and extract the small amounts plants collect from the sun. Maybe some algae growing scheme which couild be massive and harvested mostly by just pumping stuff around could be practical.

[JoeyP]

If climatology goes with any ism. it's Thatcherism. It was Margaret Thatcher who first started to throw money at any one who could show in any way form or fashion that CO2 was bad for the environment, especially if that CO2 was produced by burning coal.....
...

Thank you G7PSK. That may literally be the most interesting bit of information I've ever read in this forum (I am not being sarcastic). I had no idea that Maggie was behind the beast under which we all now suffer. Ironic example of extreme unintended consequences. She won the battle, but created a new and much larger war. I did notice years ago that (at that time) Brits seemed to be the most staunch believers in global warming, but I had no idea why. So many things make sense now.

Hilarious!   I never would have thought that an engineering forum would also have some of those types so blinded by ideology or political agenda so as to deny basic scientific facts....

Perhaps that's because you spend too much time with your palm over your face to see what really goes on in the world. Believe or not, there is a world beyond engineering. One in which politics plays the dominant role - its called the real world. get in touch with it some time.

[nctnico]

Because refining petrol to drive one mile in a typical ICE car uses more energy than a typical EV requires to drive one mile electricity consumption will actually fall when we change over.

I'm not quite following what you try to say here. Losses during refining fuel are around 12% (don't forget that crude oil is distilled into numerous producs). Besides that gas and coal need to be mined and refined as well which isn't very efficient either.

[Rufus]

From: http://www.businessinsider.com/elon-musk-and-chris-paine-explain-how-the-electric-car-got-its-revenge-2011-10

Funny, you write off a Spiegel article with "LOL, newspapers trying to sell a few copies." and quote this dip-shit who is absolutely trying to sell a few EVs.

If you divide the electrical energy consumed by oil refiners by the amount of gasoline they produce the figure is nearer 0.2kWh/gallon.  So about as accurate as the superchargers are 100% solar powered bullshit you posted the other day.

[mtdoc]

Believe or not, there is a world beyond engineering. One in which politics plays the dominant role - its called the real world. get in touch with it some time.

We'll I'm not an engineer - but a scientist and a clinician. On my clinic days I see and talk to about 20 patients a  day who come from all walks of life and political ideologies.  So you really have no idea what  you are talking about.  Electronics  is a hobby.

The thing is, I expect anti-science dumbassery from the uneducated, far right and Fox news indoctrinated types - just didn't expect to find them here.

Anywhoo - carry on - I know there is no convincing the climate change deniers with facts - it's religion with them.

[JoeyP]

Anywhoo - carry on - I know there is no convincing the climate change deniers with facts - it's religion with them.

Who said anything about denying climate change? The climate has been changing since the beginning of time.

[AG6QR]

Because refining petrol to drive one mile in a typical ICE car uses more energy than a typical EV requires to drive one mile electricity consumption will actually fall when we change over.

That's why electricity companies are no desperate to get more EVs on the road, and why there will be no crisis due to a rapid change over.

Interesting, I've not read any evidence to support that, not discrediting you, just not seen it.  Have a study for me to read up on?

However, as EVs grow and the demand on dino fuel eases, prices will go down and the more fuel is burned.  Now you have the lots of refining and lots of electrical load via EVs.

It comes from an Elon Musk quote.

http://www.plugincars.com/refining-oil-requires-more-electricity-evs.html

Distillation of petroleum does use a significant amount of heat.  The vast majority of that heat is produced by burning petroleum, not by electricity.

The only support I've seen for such a statement comes from a calculation of the total efficiency of the refining process (somewhere around 85%), and then making the false assumption that the energy used in refining was all provided by electricity.

In fact, it takes around 100kJ of electricity to refine 1 kg of crude oil, producing 2200 kJ of energy output.  The way that gets allocated among various petroleum products is tricky and subject to debate, but clearly the difference between electric energy consumption and energy output is well more than an order of magnitude.  Details are here:

http://greet.es.anl.gov/files/1c49xpjg

The statement "Refining petrol to drive one mile in a typical ICE car uses more energy than a typical EV requires to drive one mile" can be true according to some sources, but of course most of the refining energy is not delivered to the refinery in the form of electricity.  The slightly modified statement, "Refining petrol to drive one mile in a typical ICE car uses more electricity than a typical EV requires to drive one mile" is not true.  And this revised statement is what would be required to support the assertion that electricity use will go down with adoption of EVs.

[tom66]

Well back then it was mostly lead acid batteries, so around 400:1. So not practical beyond about 30 miles.
Nowadays it is less than 50:1 so the engineering solution is to put a massive battery in the vehicle.

Back then IC engine efficiency would also be rather crap evening it out a bit.

I forgot to consider this: the drivetrain in most electric cars is close to 90% efficient, if not more: the Model S can achieve 86% average, and the Prius can achieve 98% maximum (I don't know if there's a maximum efficiency for the Model S provided anywhere.) That's battery-to-wheel.

Your typical gas car does about 30 to 35% tank-to-wheel, less for a bigger engine.  The general rule is 33% to wheels, 33% out of exhaust, 33% into heat.  So your electric car has a head start in that it needs about a third the energy to go the same distance.  (Diesel engines are more efficient, apparently upwards of 45%, but compare like-for-like: a diesel is not going in a performance luxury car.) The gap is now 17:1 battery:fuel density.

Is it really considered that an order of magnitude improvement is impossible? Even a 2:1 ratio would make electric cars a lot more practical.

As far as inefficiencies go, let's look at the energy usage of a car like the Model S, versus say an Audi A8 luxury car, which does about 37 mpg (3 litre petrol engine, ~310 bhp). One gallon of petrol contains ~34kWH. So the Audi uses approx 0.92kWh per mile. The Tesla uses about 0.33kWh per mile. The efficiency of the Tesla is approximately 3 times that of the Audi, despite the fact that it contains a massively heavy lithium ion battery, costs less and has greater power output.

[mtdoc]

Who said anything about denying climate change? The climate has been changing since the beginning of time.

I did notice years ago that (at that time) Brits seemed to be the most staunch believers in global warming, but I had no idea why. So many things make sense now.

OK here's a fix:   I know there is no convincing the global warming deniers with facts - it's religion with them.

Your statement:  "Brits seemed to be the most staunch believers in global warming" says it all.  Global warming is not a matter of belief - it is a scientific fact.  So carry on with your religion. Of course you're free to believe whatever you want - no point in arguing about religion.

[JoeyP]

Who said anything about denying climate change? The climate has been changing since the beginning of time.

I did notice years ago that (at that time) Brits seemed to be the most staunch believers in global warming, but I had no idea why. So many things make sense now.

OK here's a fix:   I know there is no convincing the global warming deniers with facts - it's religion with them.

Your statement:  "Brits seemed to be the most staunch believers in global warming" says it all.  Global warming is not a matter of belief - it is a scientific fact.  So carry on with your religion. Of course you're free to believe whatever you want - not point in arguing about religion.

Religion is by definition, for believers. So carry on with your beliefs. I'll continue to pay attention to the facts, and leave the religion to you.

[tom66]

The climate is warming: fact. There is data.

Are humans causing it? Most likely: for one, the warming period lines up very nicely with the start of the Industrial Revolution. Calculated emissions of CO2 from cars and power plants provide significant contributions to the total CO2. And CO2 is a greenhouse gas, which can cause warming.

Will the models of "5°C hotter in 2050" hold up? Probably -NOT- in my opinion: given the average certainty of a temperature on a weather forecast is around 2 degrees either way, I find it hard to believe we can state that the climate will have risen by X degrees after X time with any reasonable level of accuracy.

[JoeyP]

The climate is warming: fact. There is data.

Are humans causing it? Most likely: for one, the warming period lines up very nicely with the start of the Industrial Revolution. Calculated emissions of CO2 from cars and power plants provide significant contributions to the total CO2. And CO2 is a greenhouse gas, which can cause warming.

Will the models of "5°C hotter in 2050" hold up? Probably -NOT- in my opinion: given the average certainty of a temperature on a weather forecast is around 2 degrees either way, I find it hard to believe we can state that the climate will have risen by X degrees after X time with any reasonable level of accuracy.

No one disputed that the climate is warming.

Also fact: The climate has warmed and cooled and warmed and cooled many times over history.

Not a fact: "Most Likely" doesn't sound like fact, and therein lies the dispute. Whether and to what degree warming is the result of human activity relative to naturally occurring changes.

If you guys want to have a debate about global warming (gee, I don't think it's ever been discussed here before), start your own thread and I'll join you there. Some people can probably still remember the original subject of this thread.

[G7PSK]

If climatology goes with any ism. it's Thatcherism. It was Margaret Thatcher who first started to throw money at any one who could show in any way form or fashion that CO2 was bad for the environment, especially if that CO2 was produced by burning coal.....
...

Thank you G7PSK. That may literally be the most interesting bit of information I've ever read in this forum (I am not being sarcastic). I had no idea that Maggie was behind the beast under which we all now suffer. Ironic example of extreme unintended consequences. She won the battle, but created a new and much larger war. I did notice years ago that (at that time) Brits seemed to be the most staunch believers in global warming, but I had no idea why. So many things make sense now.

Hilarious!   I never would have thought that an engineering forum would also have some of those types so blinded by ideology or political agenda so as to deny basic scientific facts....

Perhaps that's because you spend too much time with your palm over your face to see what really goes on in the world. Believe or not, there is a world beyond engineering. One in which politics plays the dominant role - its called the real world. get in touch with it some time.

I was not denying any basic facts scientific or otherwise. Its a fact that Mrs Thatcher needed to break up the power the miners union had held for so long and its also a fact that she was the one that started the heavy funding on climate change in the UK. By the by I largely supported what she was doing at that time now I am not so sure.
In the UK most houses are supplied with a 100 amps per phase usually just one phase + neutral and earth but where 3 phase  is supplied its 3 phases + neutral + earth commonly on the poles you will see just 4 wires though. 

[mamalala]

In the UK most houses are supplied with a 100 amps per phase usually just one phase + neutral and earth but where 3 phase  is supplied its 3 phases + neutral + earth commonly on the poles you will see just 4 wires though.

Thanks, didn't know that. It's different here, at least from what i have seen throughout my life.

Yes, it's normal that you only have 4 wires for three phases, it's the classic TN-C system, where you have three phases and PEN, the latter one being split up into PE and N either in the distribution/fuse box or at the main connection point of the house (if the latter, the following cabling to the fuse/distribution box is the 5 wires).

So, at least we here in Germany should have mostly no problems with EV's and their charging needs, should they become popular.

Greetings,

Chris

[johansen]

Well back then it was mostly lead acid batteries, so around 400:1. So not practical beyond about 30 miles.
Nowadays it is less than 50:1 so the engineering solution is to put a massive battery in the vehicle.

Back then IC engine efficiency would also be rather crap evening it out a bit.

I forgot to consider this: the drivetrain in most electric cars is close to 90% efficient, if not more: the Model S can achieve 86% average, and the Prius can achieve 98% maximum (I don't know if there's a maximum efficiency for the Model S provided anywhere.) That's battery-to-wheel.

Your typical gas car does about 30 to 35% tank-to-wheel, less for a bigger engine.  The general rule is 33% to wheels, 33% out of exhaust, 33% into heat.  So your electric car has a head start in that it needs about a third the energy to go the same distance.  (Diesel engines are more efficient, apparently upwards of 45%, but compare like-for-like: a diesel is not going in a performance luxury car.) The gap is now 17:1 battery:fuel density.

Is it really considered that an order of magnitude improvement is impossible? Even a 2:1 ratio would make electric cars a lot more practical.

As far as inefficiencies go, let's look at the energy usage of a car like the Model S, versus say an Audi A8 luxury car, which does about 37 mpg (3 litre petrol engine, ~310 bhp). One gallon of petrol contains ~34kWH. So the Audi uses approx 0.92kWh per mile. The Tesla uses about 0.33kWh per mile. The efficiency of the Tesla is approximately 3 times that of the Audi, despite the fact that it contains a massively heavy lithium ion battery, costs less and has greater power output.

I have a single data point to suggest that small diesel engines can achieve 30% efficiency diesel to 120vac in the form of a well tuned 3KW generator.. yes, you read that correctly. so i don't know why there are no small diesel electric hybrids. the too much weight argument doesn't pass the smell test for me.
If i had money i would build one, 30C rated lithium iron phosphate cells, diesel electric transmission, with two clutches to enable the electrical system to be bypassed when it is more efficient not to use it.

regarding battery to wheel efficiency, 80% would be really good.
let me break this down for bare minimums:
for the 200-300 volt battery boosted to 500 volts:
2 volts lost in the boost switches, 1 volt in the boost diode.
.5 volts lost in the inductor.
.5 volts lost for switching losses.
4/200 is 2%, so that's 98% right there.. yes, that's why it is water cooled.

for the inverter:
two IGBT conduction losses minimum, so that's 4 volts out of 500, or 99% which also explains why its water cooled.

motor losses vary with HP of course, but lets say it reaches peak efficiency of 96% at 30 percent full load, and it runs at 90% efficient full load, 90% efficient at 15% load. which also explains why its water cooled.
keeping it cold also reduces the resistance. copper at 140C is about 30% more ohms.

say the transmission is 99.5% efficient per spur gear.
that's 99% for a single planetary gear set.
99% for the spiral bevel gear mating with the differential.
lets say you need two gear sets.

multiply all these together (motor at 96%) and you get 90%

[tom66]

The Model S does not use a boost topology. The motor is driven directly off the unregulated 375V DC bus.
A motor can hit 99% efficiency, 95% is probably realistic.

[nctnico]

In the Prius the drive train (battery to wheels) achieves 77% to (IIRC) 96% efficiency. The 96% efficiency is only achieved in a very small operating area. At low speeds the efficiency is the worst although the power output is also lower so in absolute numbers it may not be so bad. The problem is that an EV can't change gears and keep the engine + drive electronics in an area with a high efficiency.

[Corporate666]

CNG allows to use the huge gas reserves of the US which will provide us independent energy for the next 100 years.

We can also use those CNG reserves to power electric plants - and when we "run out" of CNG, we don't really have to do anything other than switch those plants to a new fuel.  Whereas if we were to attempt a build-out of infrastructure to support 250 million cars, not to mention changing the cars themselves to CNG, that is infinitely harder.

CNG works as a fuel - for powering electric plants.  For cars, it just doesn't work.  The other thing people often forget is that user experience is a big part of all this.  It's the reason diesels never caught on in the USA... you have to find specific gas stations that sell diesel, and the cars were louder/clunkier/noisier, smelled bad, had a different driving feel, etc.  People just didn't want that.

EV's suffer much of that now.  People don't want to get stuck in a discharged vehicle nor do they want to have to charge up for hours per week.  The driving feel of EV's is fantastic... they are much quieter than ICE cars, and have less vibration and are naturally torquey down low, which is what makes a car feel "peppy".  CNG doesn't have the advantages over gasoline cars that EV's have... and they have many disadvantages.  They just won't ever catch on.

[tom66]

In the Prius the drive train (battery to wheels) achieves 77% to (IIRC) 96% efficiency. The 96% efficiency is only achieved in a very small operating area. At low speeds the efficiency is the worst although the power output is also lower so in absolute numbers it may not be so bad. The problem is that an EV can't change gears and keep the engine + drive electronics in an area with a high efficiency.

An EV can change gears -- but there's no need.

The low 77% efficiency at low end is more likely due to losses in the inverter such as drive control, coolant pump, battery management, etc. Drive train losses can also become more significant at slower speeds.

This is why all cars have lower efficiency at low speeds, because the static power usage remains pretty much the same throughout. It's rarely an issue though. At 55mph, the Tesla pulls approx 16kW from the battery, so a few hundred watts for headlamps, pumps, computers, etc is mostly insignificant.