RE: Motor Show: Lightning

[skwdenyer]

Stealth-wagon said:

Tesla Motors state that their car needs 3.5 hrs at 70amps and 110v (US mains votlage) which roughly speaking means the car needs a 27 KWh of charge. The charging solution needs a very fat cable feeding off the equivalent of 2 or 3 domestic mains.

70A @ 110V (single phase) would equate to 35A @ 220V - that's similar to the draw from a large electric cooker or a large electric hot water cylinder. I don't see why you think that's a problem in a domestic setting? Most UK properties will have at least a 100A single-phase PME supply. Larger properties will quite commonly have more (see below).

Stealth-wagon said:

In order to get 27kwh charge into the car from a standard 13a UK mains socket, you'll need to leave it charging for about 9 hours. They might resort to a dual plug solution or a domestic 3 phase installation in order to bring that charge time down - I do not know what they intend to do.

You wouldn't want to try to draw an extra 35A out of a UK domestic ring main. Anyone who wants to shell out on a Tesla can afford £100 for an electrician to wire up a ceeform socket in the garage for charging on a separate MCB. It might need an interruptor to make sure that the total board load didn't go too high, but that's not a big deal.

Returning to charging times, what we don't know are the characteristics of the load and, in particular, what power factors to use in the calculations. My house has a 100A, 3-phase supply. So do those of a lot of people I know in rural areas who don't have gas for heating and use electricity as well as / instead of oil. It is pretty common, and can be specified easily enough from the electricity companies.

If we assume that we have a power factor of 0.8, and if the Lightning needs 27kWh for a full charge, and if we have a normal 3-phase supply available, then that's just a 40A 3-phase load for a 1-hour charge, which is good enough for me

To get to 10 minutes will require a 240 Amp, 3-phase supply. This is very feasible on a semi-industrial scale. And, if you really could save £20k per year on the car, you could very easily get your house supply upgraded to, say, 300A per phase and still save a lot of money in the first year (obviously, ah-hem, ignoring the £200k vehicle cost).

[skwdenyer]

Angilion said:

Merging the HVDC line with existing national grids would be a problem, but not an insurmountable one.

The UK interconnect ("import line") to the French grid is an HVDC line. The "conversion" station is in Kent. I don't see any problem in repeating this somewhere else.

ETA: for details of desert solar - EU grids, have a look at the Trans-Mediterranean Renewable Energy Cooperation

Edited by skwdenyer on Saturday 2nd August 22:15

[skwdenyer]

Angilion said:

30 million cars in the UK.
Average 10000 miles per year per car.
So 300 billion miles total.

OK so far.

Angilion said:

Claimed milage for this car is 200 miles on 36KWh, or 5.56 miles per KWh. Probably true if you drive it like a milk float.

Then there's charging efficiency, which isn't stated. It's usually very high for charging a modern battery, so I'll be generous and pretend it's 100%.

So...the total power requirement per year if everyone used one of these cars is 53,956,834,532KWh.

Hmm, rounding error? 3x10^11 miles per year. So 3x10^11 / 200 x 36 kWh = 5.4x10^10 or 54 billion kWh.

Angilion said:

For domestic car use only. Assuming 100% charging efficiency and constant carefully economic driving by everyone all the time and assuming that the manufacturer's claims are completely true.

Hmm, the economy argument is moot, but then we'll assume that efficiency will get better over time which will make the calculation "kinder".

You ignore transmission losses as well as charging efficiency and power factor on the grid.

If we assume power factor is 0.95 (poor, but probably not far off that in many parts of the grid), and transmission / grid losses of around 10% then, broadly, we need to increase the calculated figure by about 15%.

Angilion said:

There are 8767 hours in a year.

There are actually 8765.81277 hours in a year (365 days, 5 hours, 48 minutes, and 46 seconds to be precise...). Usually rounded to 8766.

Angilion said:

Therefore the average required power output would be (53,956,834,532/8767) = 6154538KW, or 6155MW.

So corrected to 6160MW + 15% for PF/losses = 7084MW = 7GW.

Angilion said:

That's about an extra 10% over current capacity.

So, yes, the end result is very similar in overall terms. Installed UK generating capacity is around 75GW, plus we import from France already. So the numbers would suggest, indeed, that the total demand was only around 10% of total installed capacity, and less than 10% of overall UK capacity.

Now, assuming the majority of these vehicles were charged at night (which could be incentivised or even mandated) then the net result would actually be an increase in utilisation, and in particular base-load utilisation (which suits nuclear, coal, wind and wave over, say, gas for generation). So it is conceivable that, coupled with the trend towards more energy efficiency in the home and workplace, the whole thing could be accommodated without any significant expansion of generation capacity.

Angilion said:

It's 04:30 and I am tired, so I'm not confident in my numbers. Everyone feel free to check them.

Your numbers were an excellent ballpark figure, thank you!

[Pilky]

Not sure anyones mentioned this but...
Not every electric car would end its daily journey by dragging itself up the drive on the last spark of energy in its empty cells...
Very few cars would require total charging every night..true there would be a spike of charging time in the evening when comuters come home from a hard 20 mile crawl through suburban traffic or getting out of a major town or city.....
Further..those of us who would be taking their fully charged steeds into work say some 20 or 30 miles...wouldnt we take the chance to trickle charge the vehicle at work using corperately supplied solar/wind/ green chargers? or indeed would most wait and just charge when neeeded possibly every 2 0r 3 days???
Anyone seen magnetic engines??

[skwdenyer]

Pilky said:

Further..those of us who would be taking their fully charged steeds into work say some 20 or 30 miles...wouldnt we take the chance to trickle charge the vehicle at work using corperately supplied solar/wind/ green chargers? or indeed would most wait and just charge when neeeded possibly every 2 0r 3 days???
Anyone seen magnetic engines??

Emphasis added. One of the great mistakes many make - most notably central government - is misunderstanding the nature of employment in the UK. The vast majority of people in the UK work for small, very small or (possibly) medium-sized businesses. Most people do not work for a company for whom it would be economically feasible to invest in this sort of localised charging infrastructure.

[groomi]

skwdenyer said:

Pilky said:

Further..those of us who would be taking their fully charged steeds into work say some 20 or 30 miles...wouldnt we take the chance to trickle charge the vehicle at work using corperately supplied solar/wind/ green chargers? or indeed would most wait and just charge when neeeded possibly every 2 0r 3 days???
Anyone seen magnetic engines??

Emphasis added. One of the great mistakes many make - most notably central government - is misunderstanding the nature of employment in the UK. The vast majority of people in the UK work for small, very small or (possibly) medium-sized businesses. Most people do not work for a company for whom it would be economically feasible to invest in this sort of localised charging infrastructure.

Indeed. Anybody showing up at my office expecting to charge their car off my electricity will swiftly be shown the door with their P45. We have an image to uphold FFS...

[Spunagain]

I kept thinking about the LigHtning'S range so went back to my EV model. The Lightning has about half the battery capacity of the Telsa (36kWh vs 70kWh). Tesla quotes its range at 220 miles using the US mixed driving test cycle so I would expect the lighTning range to be much lower by the same measure. However as long as you go slow the range of both cars is actually a lot higher. The range for the Lightning would be about 200 miles if you kept to about 40 mph. Perversly the Lightning's urban range will be it's best as there is very little wind resistance at lower speeds and all of the braking energy is fed back to the battery due to the high carge capacity of the Altair Nano batteries.

So when a car company quotes range you need to know what it means (same as mpg, is it urban, mixed or cruising mpg). If you are on a motorway the Tesla with a fresh battery will always give a much longer range, if you are urban driving it could be a dfferent story!

I guess this is my way of back tracking and saying that the quoted range of the lightning is not necessarily untrue but could be construed as misleading as a measure of real world performance. Would you drive a car that does 0-60 inunder 4s in the town all day long?

Regards
Spunagain

[FlossyThePig]

PML Website said:

PML Flightlink Limited - in Administration
EM Shires and RW Birchall were appointed as Joint Administrators of PML Flightlink Limited on 28th November 2008 to manage its affairs, business and property. EM Shires and RW Birchall contract as agents of the Company without personal liability. EM Shires and RW Birchall are licensed to act as insolvency practitioners by the Institute of Chartered Accountants in England and Wales

PML make and supply the HiPa Drive hub motors used in the Lightning GT.

[V8 GRF]

FlossyThePig said:

PML Website said:

PML Flightlink Limited - in Administration
EM Shires and RW Birchall were appointed as Joint Administrators of PML Flightlink Limited on 28th November 2008 to manage its affairs, business and property. EM Shires and RW Birchall contract as agents of the Company without personal liability. EM Shires and RW Birchall are licensed to act as insolvency practitioners by the Institute of Chartered Accountants in England and Wales

PML make and supply the HiPa Drive hub motors used in the Lightning GT.

Might be a cheap way for the company building the Lightning to aquire the technology?

[skwdenyer]

V8 GRF said:

FlossyThePig said:

PML Website said:

PML Flightlink Limited - in Administration
EM Shires and RW Birchall were appointed as Joint Administrators of PML Flightlink Limited on 28th November 2008 to manage its affairs, business and property. EM Shires and RW Birchall contract as agents of the Company without personal liability. EM Shires and RW Birchall are licensed to act as insolvency practitioners by the Institute of Chartered Accountants in England and Wales

PML make and supply the HiPa Drive hub motors used in the Lightning GT.

Might be a cheap way for the company building the Lightning to aquire the technology?

PML Flightlink are a bit large for that, I think - they supply the motors for the Electric Mini, for instance, and have some very large customers.

It is a huge shame that, despite the rhetoric, HMG hasn't been able to help fund this world-leading business with enormous future earnings potential. If we can't save our world-class "green-related" industries, what chance the rest of us?

[Spunagain]

Hi
AC propulsion in USA supplied the entire Mini drievtrain for the recent 500 trial cars. (Same boys who licensed their technology to Tesla...)

PML did make a 1 off technology demo which was a hybrid with a similar architecture to the Fisker Karma.

Hopefully one of their customers such as Volvo will buy them up and use the Lightning as a shakedown proving ground for the technology. Otherwise I suspect Lightning will have to tear up their drive train plans and beat a path to AC propulsion's door... or follow PMLs lead into insolvency.

I hope they succeed cos that is a beautiful car.

Here's a nice example of what one man can do with an AC propulsion drivetrain - not finished yet!

http://www.attackforums.com/showthread.php?t=2419

Regards
Spunagain

Edited by Spunagain on Thursday 8th January 22:13

[crofty1984]

If it CAN charge in 10 minutes it'll be over one of the major stubling blocks. Pull up at a MOTO, plug in, go and have a coffee and a bagel, drive off.

Edited to add: the FAQ on their website said:
full charge. (Back)

Q. How long does it take to charge the Lightning?

A. There are likely to be three options: Overnight using a domestic power supply, a couple of hours using a 3 phase power supply and just 10 minutes using a fast charge unit.

Edited by crofty1984 on Thursday 8th January 17:22