Electric cars

zeupater

Joe_Horner wrote: »

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.

Hi

Or in simplistic terms, the 365000kWh tanker load delivers traction at around 30% efficiency, therefore around 110MWh, which less than 2.5minutes of generation from the proposed Wylfa plant ..or.. less than 7 minutes from either of the proposed new 1GW offshore wind developments to be connected to the grid on Anglesey ... or 1minute 22seconds to deliver from all 3 ... alternatively, 110MWh requirement over a week is 0.013% of the load of those three proposed developments ... and there'll be more developments, so what's the need to take 8hours to transport carbon intensive fuel from Stanlow to Anglesey when there's already so much low-carbon energy available on the doorstep ...

Same logic applied, just a different perspective ...

HTH
Z

Joe_Horner

zeupater wrote: »

Hi

Or in simplistic terms, the 365000kWh tanker load delivers traction at around 30% efficiency, therefore around 110MWh, which less than 2.5minutes of generation from the proposed Wylfa plant ..or.. less than 7 minutes from either of the proposed new 1GW offshore wind developments to be connected to the grid on Anglesey ... or 1minute 22seconds to deliver from all 3 ... alternatively, 110MWh requirement over a week is 0.013% of the load of those three proposed developments ... and there'll be more developments, so what's the need to take 8hours to transport carbon intensive fuel from Stanlow to Anglesey when there's already so much low-carbon energy available on the doorstep ...

Same logic applied, just a different perspective ...

HTH
Z

Because the currents involved and the infrastructure to deliver amd store all those joules locally are the same pretty well regardless of how close the generation is. Unless you're suggesting we all go and charge up directly from 25kV at Wylfa?

Have you seen the roads to that place???


eta:

Incidentally, even if the above wasn't true, i happened to pick Anglesey for absolutely no other reason than that's where I am.

Are you seriously suggesting that we build a new nuclear plant and 2 x Gw wind farms within 20-odd mile radius of every population in the Uk? In the name of saving the planet??? Because that's plain swivel-eyed bat-crazy!

Martyn1981

Joe_Horner wrote: »

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

That's quite funny, because you go on to compare the diesel at 100% to leccy, whereas of course it's not, it's more like 30% efficient.

I also liked the bit where you try to deliver the leccy in that same 8hr period, rather than the time that that diesel supply actually provides fuel.

Then you mention batteries for local storage as a negative, but did you consider the large 'batteries' for diesel storage at the refinery, the tanker trailer, and the fuel depot storage tanks ..... so three large batteries ...... if you want to use fair, reasonable and rational comparisons.


Later on you shoot yourself down completely!

Joe_Horner wrote: »

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.

Remember, that tanker contains about 365000 kWh of energy, and we're sharing it between 3 stations.

So, in case you didn't realise what you've done here, you've said that the capacity needed to use leccy is three times single phase (which domestic properties have), so 3 phase then, what commercial properties have.

So a single 3 phase commercial connection could carry that load. You've just destroyed your own argument.

Then we have the fact that only around 1/3 of the diesel energy is used, so in effect single phase would do it (I have single phase in my house with a 100A supply).

Then you decide to completely destroy your argument and say that the tanker supplies 3 fueling stations, each of which will have a leccy supply.

So taking fuel efficiency into account, the fuel stations on single or 3 phase will be able to handle 3 to 9 times as much leccy energy.


Please, please, please think about this, I'm not destroying your argument, you are, with reality.

Martyn1981

Joe_Horner wrote: »

Are you seriously suggesting that we build a new nuclear plant and 2 x Gw wind farms within 20-odd mile radius of every population in the Uk?

Hiya, the generation source doesn't have to be within 20 miles. Unlike the tankers which have to drive 8hrs (for example), leccy can be transported around the UK via the national grid, with less losses than the fuel consumption of the diesel tanker hauling the diesel from from one battery to another, via it's own battery.

Joe_Horner wrote: »

In the name of saving the planet??? Because that's plain swivel-eyed bat-crazy!

Actually CO2 emissions from transport are huge, and without tackling them (and emissions from space heating) AGW can not be dealt with.

Transport could be seen as a huge problem, and of course is, but the EV's that have now hit the road for ICE car replacement are now capable, we just need a ramp up of production, and the continued cost reduction.

For HGV's the saving are even greater, as I explained earlier, with paybacks of 2yrs or less.

Many folk think that the amount of leccy needed is impossible for such a switch, but simple analysis of cars, based on 30m and an average of 7,900 miles pa, shows that we'd only need to increase leccy generation by 20%. We already have that capacity spare at night from gas plants, and this can steadily be changed over to RE generation as the rollout continues.

In fact the impact on the UK is closer to 10%, not 20%, as refining petrol/diesel takes about 6kWh per gallon, or approx 50% of that extra leccy.

Joe_Horner

Martyn1981 wrote: »

That's quite funny, because you go on to compare the diesel at 100% to leccy, whereas of course it's not, it's more like 30% efficient.

I also liked the bit where you try to deliver the leccy in that same 8hr period, rather than the time that that diesel supply actually provides fuel.

Then you mention batteries for local storage as a negative, but did you consider the large 'batteries' for diesel storage at the refinery, the tanker trailer, and the fuel depot storage tanks ..... so three large batteries ...... if you want to use fair, reasonable and rational comparisons.


Later on you shoot yourself down completely!



So, in case you didn't realise what you've done here, you've said that the capacity needed to use leccy is three times single phase (which domestic properties have), so 3 phase then, what commercial properties have.

So a single 3 phase commercial connection could carry that load. You've just destroyed your own argument.

Then we have the fact that only around 1/3 of the diesel energy is used, so in effect single phase would do it (I have single phase in my house with a 100A supply).

Then you decide to completely destroy your argument and say that the tanker supplies 3 fueling stations, each of which will have a leccy supply.

So taking fuel efficiency into account, the fuel stations on single or 3 phase will be able to handle 3 to 9 times as much leccy energy.


Please, please, please think about this, I'm not destroying your argument, you are, with reality.

You didn't read very well, did you? I made the point about 3 phase myself. maybe this makes it clearer?

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.

...

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.

It's then also correct to say that the whole tanker (delivering to 3 stations) delivers the same energy as a full 3 phase supply.

In your last paragraph you've then made a schoolboy maths error and applied the "divide by 3" twice - once on the supply phases and again on the number of deliveries. Big numbers are hard, I know, but do try to do the sums right :beer:

Martyn1981

Joe_Horner wrote: »

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.

Apologies, I missed this little nugget earlier.

Taking domestic EV's as an example, it's already far more efficient to run an EV and charge it from home via the electrical infrastructure, than to run it on diesel or petrol. So reality seems to trump your belief/claims yet again.

I'm not sure why you believe this isn't practical, it's already happening ..... a bit like Tesla model 3 deliveries and the ramp up of production that have earlier been denied, repeatedly.

Martyn1981

Joe_Horner wrote: »

In your last paragraph you've then made a schoolboy maths error and applied the "divide by 3" twice - once on the supply phases and again on the number of deliveries. Big numbers are hard, I know, but do try to do the sums right :beer:

Hiya, I appreciate you changed the story later on, that's why I dealt with it in order.

Nope, no mistake on the maths, if the diesel has 1/3 the efficiency of leccy, then it can be matched by single phase, so 3 stations will be 3x. If on 3 phase, then you have 9x.

AnotherJoe

I run an EV. 100% (within statistical error) of my charging is at home. So I dont need any additional charging points built, and neither will most drivers once the range of most EVs gets to around 250 miles, which is maybe only 5 years off. (If i go somewhere more than 250 miles I'll get a train or fly anyway).

Sure there will need to be more charge points built but its not a simple maths equation that if X cars need Y charging points, 10x cars need 10Y charging points because as range increases, then there is a step change drop in the need to recharge away from home, and at some point, that goes to zero instead of a fraction.

Which is the Tesla truck issue, naysayers panicabout how long it takes to charge, but if its being used on routes that are under 500 miles, then its not being charged enroute at all. Its not aimed at 2,000 miles long haul. Or maybe Pepsi, Walmart, UPS, Anheiser, Ryder, etc etc are run by complete idiots who dont understand that and will run out in the middle of some US highway?

And, getting more parochial, currently (ha ha see what i did there) much UK wind power generation is actually turned off at night since there's literally nowhere for it to go whereas if people are charging on cheap electricity at night, thats a win win win (better utilisation of wind, less peak load, cheaper charging). So all the guff about transporting so many megajoules in one journey becomes an irrelevance because instead of more infrequent but larger fill ups, its more frequent and slower fill ups which because they are overnight, doesn't matter.

I'm sure many people here would be quite happy to have a car that took petrol at 25p a litre but only at a trickle so it could only refuel overnight, as long as the range they had in the morning was sufficient. Thats what most EV owners experience now. Thats likely less than 5 years away for 80% of the population taking into account occasional longer journeys, (since for most journeys most people could do it right now)

All thats needed to settle these arguments now is a little time, because all the ridiculous scaremongering /misinformed guff we see about x zillion charging stations needed or the nation shutting down at 6pm when everyone plugs their car in will be shown to be bunk in a very short order.

IanMSpencer

We were discussing this at home. The idea of an infrastructure being required to support EV on the move is a nonsense. The cost of designing cars that have a range of 250 miles or so which will cover 99% or more of all user requirements is trivial compared with the logistical nightmare of creating fast charging hubs around the country.

For the remainder of car users, the alternatives are hybrids, especially super-hybrids which are really EVs with range extenders. I would have thought that small, super-clean generators that can run at peak generating efficiency would make little difference in terms of pollution than a conventional power station.

I also think, fast charging at home will be a no-no in the long term. I would assume the grid can withstand the extra load of a 3 bar heater in most houses at night with only minor tweaks here and there - there may be a problem with early evening peak power as people plug in straight away on returning home and probably don't worry about timing unless they are on Economy 7. However, the thought of people using fast charging in most homes would lead to a need to bolster the home network.

Of course the generation issue is still to be resolved. I am entirely unclear what the impact will be on the demand for generation, given that we apparently need significant nuclear investment to meet current requirements and it is not clear to me whether the transfer of energy requirements onto the national grid has been accounted for in the future growth of UK generation. I fear that the government may have decided it did not need the experts when it made its declaration for future EV use.

Martyn1981

AnotherJoe wrote: »

I run an EV. 100% (within statistical error) of my charging is at home.

Hiya, I can't recall the percentage exactly, but I think Tesla owners in the States get about 3%-5% of their leccy from superchargers. Most is as you say home charging, and perhaps in future more will be at destination chargers (shops, car parks etc). The Tesla figures may be skewed higher due to free charging for S & X models.

For a comparison of fuel efficiency, the average driver needs less than 1kW draw through the night (say 5.5kWh) to charge the car for a days driving, so no need to drive to the petrol station, no need for the petrol station, and no need for the tanker fleet for the petrol stations .... in an ideal world.

That seems much more efficient to me.