Electric cars

zeupater

Joe_Horner wrote: »

Not at all, but the same basic physics applies. If there are 8 charging ports then you still the same total cross section to (safely) carry the total current. So that's still nearly a quarter ton of conductor for 4 metre leads, and by splitting into more cables the insulation and sheathing requirements will be even greater. It doesn't matter how clever Mr Musk may be, he's not allowed to re-write basic physics.

As for "mechanical charging", that might conceivably be viable if manufacturers standardise all aspects of the charging ports - size, configuration, position on the vehicle and so on. Even you have to admit that doesn't appear likely. Any time soon. And without that any automated connection is going to be manufacturer, or even vehicle, specific and will have to be duplicated, at least in part, for other marques.

Hi

So you're effectively saying that the existing network of Tesla Superchargers don't exist and wouldn't work even is they did ... take for example the 12x120kW ones on the M1 at Newport Pagnell ...

12 superchargers, available 24/7, up to 120kW

<Newport Pagnell Tesla Superchargers>

Now last time I looked 12 vehicles charging at 120kW = 1.44MW ... okay, so the 12 120kW ports are physically separated by a little over the width of a car being charged and there's a current infrastructure limitation of 145kW between two adjacent ports, but what happens if (say) the limitation was overcome by laying in better power delivery infrastructure and 8 of the ports were combined into a single automated connection interface, or simply 8 manual ones for charging? .. that's 960kW, not far from the 1.2MW which was claimed impossible a few posts back - simply uplift the power from 120kW/port to 150kW then you have 1.2MW over 8 ports.

Okay, to your 1/4 tonne for 4metre suggests that the current Tesla supercharger leads weigh approx 32kg ... that's about 1/3 more than a sack of potatoes, yet misses the point that it's not necessary to lift the entire free weight if the cable ... other points to consider are automated port connectivity & cable cooling technologies (a potential 'basic physics' myth-buster!) which are known to be in the pipeline (forgive the pun!)

Regarding 'standardisation' of port configuration ... simple - RS232, USB, SVGA, the list is endless - standardisation in the automotive industry is widespread and totally understood ... it's likely that international standards are being worked on on a collaborative basis right now, but if not they'd almost certainly be based on the first entry to the mass market as that's how the automotive sector tends to work ...

HTH
Z

Martyn1981

Joe_Horner wrote: »

It doesn't matter how clever Mr Musk may be, he's not allowed to re-write basic physics.

So, are you stating that it's not possible? Are you stating that Tesla can't do it?

Joe_Horner wrote: »

As for "mechanical charging", that might conceivably be viable if manufacturers standardise all aspects of the charging ports - size, configuration, position on the vehicle and so on. Even you have to admit that doesn't appear likely. Any time soon. And without that any automated connection is going to be manufacturer, or even vehicle, specific and will have to be duplicated, at least in part, for other marques.

So, just to be clear, the Tesla Mega-chargers, won't be able to use mechanical charging, because the Tesla trucks won't have standardised charging ports on them? Oh boy!


BTW, any reason why the cables have to be 4m long, can't the lorries park closer? Also do you remember when fuel hoses were suspended off an arm so you didn't have to hold them up ...... just saying.

It seems that your earlier claim

Joe_Horner wrote: »

The only way to reduce that

is in tatters, as, as well as higher voltage, we could have multiple cables, mechanical charging, cables suspended/counterweighted, and shorter cables ..... or a combination of one and all.


This thread is now full of 'experts' explaining how what is being done, can't be done. What's the point? In a few years this will all have happened, so why waste time 'explaining' why it can't / won't, and especially by so many people who don't seem to know any of the specifics, or even to have bothered to have researched what they are saying.

[Edit - I should probably explain the above rudeness - I've already heard the exact same 'expert' conclusions, 10yrs ago for on-shore wind, 5yrs ago for PV, 2yrs ago for off-shore wind ..... so perhaps my patience is wearing thin for the negative naysayers who always deny what is happening via a thin veneer of pseudo science, whilst failing to stay up to date on the facts. A 'thicko' like me, with access to Google should not be better informed than those claiming to be supported by the laws of physics (time after time after time). M.]

Joe_Horner

zeupater wrote: »

Hi

So you're effectively saying that the existing network of Tesla Superchargers don't exist and wouldn't work even is they did ... take for example the 12x120kW ones on the M1 at Newport Pagnell ...
<Newport Pagnell Tesla Superchargers>

Now last time I looked 12 vehicles charging at 120kW = 1.44MW ... okay, so the 12 120kW ports are physically separated by a little over the width of a car being charged and there's a current infrastructure limitation of 145kW between two adjacent ports, but what happens if (say) the limitation was overcome by laying in better power delivery infrastructure and 8 of the ports were combined into a single automated connection interface, or simply 8 manual ones for charging? .. that's 960kW, not far from the 1.2MW which was claimed impossible a few posts back - simply uplift the power from 120kW/port to 150kW then you have 1.2MW over 8 ports.

Okay, to your 1/4 tonne for 4metre suggests that the current Tesla supercharger leads weigh approx 32kg ... that's about 1/3 more than a sack of potatoes, yet misses the point that it's not necessary to lift the entire free weight if the cable ... other points to consider are automated port connectivity & cable cooling technologies (a potential 'basic physics' myth-buster!) which are known to be in the pipeline (forgive the pun!)

Regarding 'standardisation' of port configuration ... simple - RS232, USB, SVGA, the list is endless - standardisation in the automotive industry is widespread and totally understood ... it's likely that international standards are being worked on on a collaborative basis right now, but if not they'd almost certainly be based on the first entry to the mass market as that's how the automotive sector tends to work ...

HTH
Z

Not going to pick through all the glib assumptions in your post cos I'm on a phone @ the moment whivh makes formatting tricky, but thete's one glaring problem right at the start.

Nowhere have I suggested it's impractical to deliver a megawatt or more to a site - of course it is, many factories use more than that.

But you're suggesting that converting 2/3 of an entite showcade supercharging station to charge a single HGV every 30 minutes shows it's scalable to practical levels.

Think about it. UK HGV traffic in 2016 was estimated at 16.6 billion miles. If we're generois and allow 400 miles per charge that equates to 41.5 million charging cycles, each lasting 30 minutes, which is 20.75 million charging hours.

With 8766 hours in a year (averaging leap years out), and allowing for using ALL tjeir capacity, with none left over for cars, that would require just short of 1600 charging points like the showcase special you suggested in operation, without fail, 24/7/365.25.. And they'd better be in exactly the right places because anyone nabbing a part recharge "early" is going to throw the whole schedule out.

Even if we accept that only 1/10th of the current mileage will go electric, someone's still got to bud another 159 Newport Pagnells - in exactly the right places, remember...

People tend to have difficulty understanding, and so underesti.ate, the difficulties involvex in dcaling "simple" ideas to the vast numbers that an entire country operates by. It's why "£350 million for the NHS" sounds so persuasive. It's a huge number. But it's lityle more than a drop in a national budget.

Similarly, 12 x 140kW vhargers (but limited in pairs) sounds like oodles of power. It is, but it isn't even the residue from a sneeze in the power provided daily by fossil fuels.

When proponents of electric vehicles stat acknowledging the difficulty of scale then i promise I'll start taking the vehicles seriously as more than a remedy for feelimg of eco-guilt.

Martyn1981

Joe_Horner wrote: »

Not going to pick through all the glib assumptions in your post cos I'm on a phone @ the moment whivh makes formatting tricky, but thete's one glaring problem right at the start.

Nowhere have I suggested it's impractical to deliver a megawatt or more to a site - of course it is, many factories use more than that.

But you're suggesting that converting 2/3 of an entite showcade supercharging station to charge a single HGV every 30 minutes shows it's scalable to practical levels.

Think about it. UK HGV traffic in 2016 was estimated at 16.6 billion miles. If we're generois and allow 400 miles per charge that equates to 41.5 million charging cycles, each lasting 30 minutes, which is 20.75 million charging hours.

With 8766 hours in a year (averaging leap years out), and allowing for using ALL tjeir capacity, with none left over for cars, that would require just short of 1600 charging points like the showcase special you suggested in operation, without fail, 24/7/365.25.. And they'd better be in exactly the right places because anyone nabbing a part recharge "early" is going to throw the whole schedule out.

Even if we accept that only 1/10th of the current mileage will go electric, someone's still got to bud another 159 Newport Pagnells - in exactly the right places, remember...

People tend to have difficulty understanding, and so underesti.ate, the difficulties involvex in dcaling "simple" ideas to the vast numbers that an entire country operates by. It's why "£350 million for the NHS" sounds so persuasive. It's a huge number. But it's lityle more than a drop in a national budget.

Similarly, 12 x 140kW vhargers (but limited in pairs) sounds like oodles of power. It is, but it isn't even the residue from a sneeze in the power provided daily by fossil fuels.

When proponents of electric vehicles stat acknowledging the difficulty of scale then i promise I'll start taking the vehicles seriously as more than a remedy for feelimg of eco-guilt.

Diesel is far less efficient than leccy, so a much greater amount of raw energy is currently be transported around the UK to keep the diesel trucks going, and that infrastructure appears to work fine.

So not sure why you think less total energy from leccy, transported directly by cable is less possible.

Martyn1981

Joe_Horner wrote: »

Think about it. UK HGV traffic in 2016 was estimated at 16.6 billion miles. If we're generois and allow 400 miles per charge that equates to 41.5 million charging cycles, each lasting 30 minutes, which is 20.75 million charging hours.

Whilst we're thinking about it (as you suggest), can you confirm that all EV trucks, will be charged all of the time at Mega-charger stations?

Is there any possibility that, I don't know, they may also be charged at base overnight, or during loading and unloading?

If only Tesla had said something about this at the launch, perhaps a statement like '80% of US routes are less than 250 miles', so a 500 mile truck could get there and back without recharging on route, and then be recharged overnight.

Just a thought, or perhaps something to 'think about'.

PS I can't wait for the day that we see fuel tankers being pulled by an EV tractor, the irony will be incredible.

Joe_Horner

Martyn1981 wrote: »

Diesel is far less efficient than leccy, so a much greater amount of raw energy is currently be transported around the UK to keep the diesel trucks going, and that infrastructure appears to work fine.

So not sure why you think less total energy from leccy, transported directly by cable is less possible.

It's all because of the immense energy density of hydrocarbon fuels.

One litre of diesel contains about 38MJ of energy.

A typical forecourt HGV pump can dispense around 90 littes per minute, or 1.5 litres per second. That's a flow of 57MJ of energy every second.

A good diesel engine can convert fuel to power with around 45% efficiency, so let's say 30% to be really hard on them. That gives a flow of 17.5 "useable" megajoules per second out of a rubber hose.

Now, one kWh is 3.6MJ of energy. So the fuel pump delivers 4.8kWh of energy (that's a 4.8kW load running for an hour) every second. To deliver the same energy through cables, at the same rate, would need a 17 Megawatt supply. That's assuming 100% efficiency through the entire supply, storage and use cycle. Charge 20 or so lorries at once, that's the entire output from a large windfarm all used up.

And that's why it's feasible to transport far more energy in liquid fuel than by cable, even when rigging the efficiency estimates heavily in favour of electric.

Martyn1981

Joe_Horner wrote: »

A good diesel engine can convert fuel to power with around 45% efficiency, so let's say 30% to be really hard on them. That gives a flow of 17.5 "useable" megajoules per second out of a rubber hose.

So at 30-45% efficiency, a nationwide network of energy supply that has to be physically transported is possible, but at around 80% efficiency and via the electrical network, it's not?


I recall a US share 'expert' explaining a year ago that Tesla would shortly collapse, as the number of charging stations was far less than the number of fuel stations in the US.

It created great hilarity from the EV world who went on to point out that 100's of millions of 'fueling stations' already exist in the US for EV's.

zeupater

Martyn1981 wrote: »

Diesel is far less efficient than leccy, so a much greater amount of raw energy is currently be transported around the UK to keep the diesel trucks going, and that infrastructure appears to work fine.

So not sure why you think less total energy from leccy, transported directly by cable is less possible.

Hi

It's not really the energy expended in transport etc that makes a difference ... the embedded energy expended in the refining process combined with the traction conversion inefficiency is the major component of the energy being transported, not the small fraction which actually moves the vehicle - this is what most don't factor into their calculation within any such debate ...

HTH
Z

Joe_Horner

Martyn1981 wrote: »

So at 30-45% efficiency, a nationwide network of energy supply that has to be physically transported is possible, but at around 80% efficiency and via the electrical network, it's not?

You don't gt this whole "energy density" bit, do you?

If a tanker leaves Stanlow and heads to us here on Anglesey, it might take a full 8 hour driving day to finish deliveries. In that 8 hours it can deliver about 35000 litres of diesel. That's enough for around 3 small fuel stations or 1-2 big ones.

That diesel represents 1.33 TJ of energy - that's 1.3 million million joules, or 369444 kWh.

To deliver the same energy by overhead line, in the same 8 hours, at 137kV would require a continuous current of 370 amps.

When it hits the local distribution at 11kV that current will increase to 4618 amps.

By the time it hits the 415v 3 phase supplied to service stations, the 3 small ones would be receiving 12 240 amps each, or the bigger ones over 20000 amps.

Even if we allow for the fact that they can take all day & night, the current required over a full 24 hours to deliver the same energy as one tanker of diesel would be 582 amps.

But the tank of fuel lasts more than a day so lets give them a continuous week to receive the same energy. Over 7 days they'd still need to draw a continuous 83 amps. That's almost the capacity of one phase to deliver a third of a tanker's worth of energy.

So a single tanker, in an 8 hour day, can deliver the same energy as a standard industrial electrical supply would take a full 24/7 week to deliver running at full capacity on all 3 phases.

Of course, that's not taking into account the fact that the station would need local storage for all that energy because people don't turn up to refuel in a nice steady line evened out over the day and night. So that's another HUGE set of batteries, with their own construction, installation, maintenance, operating losses and disposal problems to contend with.

Remember, that tanker contains about 365000 kWh of energy, and we're sharing it between 3 stations. That's 100000kWh for each. Even if we only have storage for half that amount, on the basis some will be used while more is coming in, that's 50000kWh of storage. Which is 500 of Tesla's 100kWh batteries, ignoring any losses.

Obviously usage patterns could be changed to help mitigate the problems but the above is simply an illustration of why transporting and storing "inefficient" liquids is, and will remain for a long time, far more practical than transmitting the same energy electrically.

zeupater

Joe_Horner wrote: »

Not going to pick through all the glib assumptions in your post cos I'm on a phone @ the moment whivh makes formatting tricky, but thete's one glaring problem right at the start.

Nowhere have I suggested it's impractical to deliver a megawatt or more to a site - of course it is, many factories use more than that.

But you're suggesting that converting 2/3 of an entite showcade supercharging station to charge a single HGV every 30 minutes shows it's scalable to practical levels.

Think about it. UK HGV traffic in 2016 was estimated at 16.6 billion miles. If we're generois and allow 400 miles per charge that equates to 41.5 million charging cycles, each lasting 30 minutes, which is 20.75 million charging hours.

With 8766 hours in a year (averaging leap years out), and allowing for using ALL tjeir capacity, with none left over for cars, that would require just short of 1600 charging points like the showcase special you suggested in operation, without fail, 24/7/365.25.. And they'd better be in exactly the right places because anyone nabbing a part recharge "early" is going to throw the whole schedule out.

Even if we accept that only 1/10th of the current mileage will go electric, someone's still got to bud another 159 Newport Pagnells - in exactly the right places, remember...

People tend to have difficulty understanding, and so underesti.ate, the difficulties involvex in dcaling "simple" ideas to the vast numbers that an entire country operates by. It's why "£350 million for the NHS" sounds so persuasive. It's a huge number. But it's lityle more than a drop in a national budget.

Similarly, 12 x 140kW vhargers (but limited in pairs) sounds like oodles of power. It is, but it isn't even the residue from a sneeze in the power provided daily by fossil fuels.

When proponents of electric vehicles stat acknowledging the difficulty of scale then i promise I'll start taking the vehicles seriously as more than a remedy for feelimg of eco-guilt.

Hi

In order ...

'Glaring problem' ... odd to mention that in passing when running EV charging down, then not supporting the statement -

'Nowhere have I suggested it's impractical' ... then it's agreed that installing EV charging infrastructure is practical, all that's needed is work on the current network, which is eminently possible without major NG investment through utilising the distributed generation which is being installed, including solar & battery storage at charging stations by Tesla themselves.

'But you're suggesting that converting 2/3' .. absolutely not. You're obviously taking an example made & assuming that the 12 charging points at the Newport Pagnell site will be the only ones needed ... when there's 24 it'll be 1/3, when 240: 1/30, when 2400:1/300 add induction charging to parking spaces and it becomes an everyday consumer expectation ...

'.. 41.5 million charging cycles, each lasting 30 minutes' .. rather large & obviously convenient 'error' here ... Firstly, that's per year, so 114k/day, with many of the vehicles able to be charged at slower rates whilst parked-up for long periods, many in home depots etc, so possibly not using the fastest charging technologies other than on the odd-occasion.

' .. require just short of 1600 charging points like the showcase special you suggested in operation' .. a convenient expansion of the above convenient 'error' on logic ... so, what happens when just changing the viewpoint a little & assuming that only 10% of the vehicle fleet need to take a fast charge at such points, does it not, by your own logic reduce to just 160 points? ...

'Even if we accept that only 1/10th of the current mileage will go electric, someone's still got to bud another 159 Newport Pagnells - in exactly the right places' ... isn't that the same flawed logic again - following that logic then with 1/10th of the mileage on electric and 90% of the charging not on the fastest chargers then the answer is 15.9? ... totally ridiculous exercise because it's not logical, along the same lines as saying that there's only a need for a certain limited number of 100% utilised petroleum filling stations in the country and that transport/haulage operators only use motorway services to provide fuel ..

'Similarly, 12 x 140kW' ... correct it is a drop in the ocean of the total energy requirements, but the proportion of the energy sector linked to fossil fuels is reducing, however, the argument used seems to be contradicted in your later post by saying " Charge 20 or so lorries at once, that's the entire output from a large windfarm all used up." ... odd really, it's either insignificant, or significant - by the way 1.2MW charging for 20 lorries is 24MW, the equivalent of about 7 modern individual turbines (not even the largest) at nameplate capacity, or 18 at a reasonable capacity factor of 40% ... the UK at this moment is generating enough electricity by wind alone to simultaneously charge 8250 vehicles on 1.2MW 30 minute chargers ... using your own capacity logic that's about 60billion miles (8250*2*24*400*365) of road transport/year, so roughly around 4x the 16.6 billion miles you raised earlier, and we've only just scratched the surface 1/1000th of the total UK area low altitude offshore wind capacity, even then, don't worry too much, because there's plenty of other energy generation sources, including displacing the petroleum industry embedded refining energy .. it's just a solution to a distribution issue we're looking at and that's about it ...

So it's not impossible, it's not even impractical & it certainly looks to be coming down the line pretty quickly, it's just a matter of scalability & economies of scale taking hold, then it's just another everyday happening ...

HTH
Z