Autocar: Tesla Model S vs Aston Martin Rapide S
Discussion
Troubleatmill said:
The biggest problem is..
The UK is running at over 95% capacity of the electric power grid.
Successive governments are not investing heavily enough in generating more capacity.
The generating companies are holding fire until it is clear what the UK policy is.
In 2017, it is estimated that we will be at 100% of capacity.
So... how viable is the electric car, when we will be scrabbling to charge our smartphones.
Fully agree that Tesla is impressive. UK energy investment - not so much.
Is it? Even if it is this will obviously refer to peak demand, which is probabaly likely to be highest at the end of a major football game when everyone sticks the kettle on, not when people are charging their cars.The UK is running at over 95% capacity of the electric power grid.
Successive governments are not investing heavily enough in generating more capacity.
The generating companies are holding fire until it is clear what the UK policy is.
In 2017, it is estimated that we will be at 100% of capacity.
So... how viable is the electric car, when we will be scrabbling to charge our smartphones.
Fully agree that Tesla is impressive. UK energy investment - not so much.
Given that most people will charge their electric cars overnight when demand is low is this really going to be an issue?
I suspect not.
No mention of it being an issue here
http://www.nationalgrid.com/NR/rdonlyres/45D855F7-...
Troubleatmill said:
The UK is running at over 95% capacity of the electric power grid.
No it's not.Our average power draw is only about half capacity. Peak load is high but it's not beyond the wit of man to stop charging cars at peak times. We have absolutely massive over-capacity at night when most charging would happen.
If you look at the figures (very roughly)...
There are about 30m private cars in the UK covering an average of 10k miles each so that's 300 billion miles per year. An 85kwh electric car can do, say, 250 miles on a charge, so that's 250/85 miles per kwh. So that's 100 billion kwh (100 Twh) of electricity per year to power every private car in the UK.
The national grid's capacity is about 80Gw; 80 * 24 * 365 = 700 Twh per year, of which we use around 360Twh (almost exactly half). So if every private car in the UK was powered entirely by electricity (which will almost certainly never happen) it would only use about 15% of the current total grid capacity, or 30% of the spare capacity, to charge them. If you assume 10% of current private car miles being electric (probably a reasonable maximum in the foreseeable future) it would only use 3% of the current slack in the grid to charge them.
There are about 30m private cars in the UK covering an average of 10k miles each so that's 300 billion miles per year. An 85kwh electric car can do, say, 250 miles on a charge, so that's 250/85 miles per kwh. So that's 100 billion kwh (100 Twh) of electricity per year to power every private car in the UK.
The national grid's capacity is about 80Gw; 80 * 24 * 365 = 700 Twh per year, of which we use around 360Twh (almost exactly half). So if every private car in the UK was powered entirely by electricity (which will almost certainly never happen) it would only use about 15% of the current total grid capacity, or 30% of the spare capacity, to charge them. If you assume 10% of current private car miles being electric (probably a reasonable maximum in the foreseeable future) it would only use 3% of the current slack in the grid to charge them.
kambites said:
If you look at the figures (very roughly)...
There are about 30m private cars in the UK covering an average of 10k miles each so that's 300 billion miles per year. An 85kwh electric car can do, say, 250 miles on a charge, so that's 250/85 miles per kwh. So that's 100 billion kwh (100 Twh) of electricity per year to power every private car in the UK.
The national grid's capacity is about 80Gw; 80 * 24 * 365 = 700 Twh per year, of which we use around 360Twh (almost exactly half). So if every private car in the UK was powered entirely by electricity (which will almost certainly never happen) it would only use about 15% of the current total grid capacity, or 30% of the spare capacity, to charge them. If you assume 10% of current private car miles being electric (probably a reasonable maximum in the foreseeable future) it would only use 3% of the current slack in the grid to charge them.
More importantly, that would be 30m huge battery packs, most of which, will be connect to the grid for 90% of the time and will be able to supply as well as draw from the grid.There are about 30m private cars in the UK covering an average of 10k miles each so that's 300 billion miles per year. An 85kwh electric car can do, say, 250 miles on a charge, so that's 250/85 miles per kwh. So that's 100 billion kwh (100 Twh) of electricity per year to power every private car in the UK.
The national grid's capacity is about 80Gw; 80 * 24 * 365 = 700 Twh per year, of which we use around 360Twh (almost exactly half). So if every private car in the UK was powered entirely by electricity (which will almost certainly never happen) it would only use about 15% of the current total grid capacity, or 30% of the spare capacity, to charge them. If you assume 10% of current private car miles being electric (probably a reasonable maximum in the foreseeable future) it would only use 3% of the current slack in the grid to charge them.
The Vambo said:
More importantly, that would be 30m huge battery packs, most of which, will be connect to the grid for 90% of the time and will be able to supply as well as draw from the grid.
I don't think I can see that happening in domestic installations - it'd just be too expensive to install synchronised inverters into so many houses. I suppose it might be possible in bit car-parks, etc. The Vambo said:
More importantly, that would be 30m huge battery packs, most of which, will be connect to the grid for 90% of the time and will be able to supply as well as draw from the grid.
I don't think I can see that happening in domestic installations - it'd just be too expensive to install synchronised inverters into so many houses. I suppose it might be possible in bit car-parks, etc. Devil2575 said:
kambites said:
I don't think I can see that happening in domestic installations - it'd just be too expensive to install synchronised inverters into so many houses. I suppose it might be possible in bit car-parks, etc.
The national grid see it as a possibility.anoother said:
Anyone else unable to watch this due to bandwidth limitations?Some great insights into power usage here but it is the range of the car which would preclude me from buying it (apart from the fact I can't afford one!). About 5 times per year I do a return journey of 700 miles, almost always within one day and generally taking about 14 hours, the main stationary time being on the cross channel ferry. Based on the current figures that would require at least one 6 hour stop to get there which would essentially mean an overnight stop, almost doubling the effective journey time so until Tesla get their battery changing network in place across Europe it isn't going to be realistic for me. I think the battery swap is brilliant though, and the sort of thing needed to make the car acceptable but somehow I suspect it will cost more than £4 to swap for a fully charged battery.
The other thing I don't like is the touch-screen I saw the Tesla at the Geneva show this year, it is a great looking car but that screen in the dash is just too much for me, it does look like an overgrown iPad has been put in there after the rest of the dash was designed. It just doesn't look right, although the tech is very appropriate.
The other thing I don't like is the touch-screen I saw the Tesla at the Geneva show this year, it is a great looking car but that screen in the dash is just too much for me, it does look like an overgrown iPad has been put in there after the rest of the dash was designed. It just doesn't look right, although the tech is very appropriate.
I think you need to be a bit careful about the cost comparisons on a purely "fuel" basis, because so much of the price of road fuels in the UK is tax! Although it costs you say £65 to fill up your car with petrol, the fuel actually only costs something less than half of that. As such, comparing the price of non road use electricity is really a bit of a false picture. Yes, in the short term it will be cheaper, but at some point either the electricity used for road transport will attract the tax, or conventional fuels will loose there tax in favour of direct road charging etc!
kambites said:
AnotherClarkey said:
ISTRC that the orginal plan for the Tesla Roadster was to have a 2 speed box but they never got it quite right for production?
I seem to remember that first gear kept disintegrating. 
I would normally moan about such behaviour, but the mentality does seem to have got the job done for Tesla with this thing!
Max_Torque said:
I think you need to be a bit careful about the cost comparisons on a purely "fuel" basis, because so much of the price of road fuels in the UK is tax! Although it costs you say £65 to fill up your car with petrol, the fuel actually only costs something less than half of that. As such, comparing the price of non road use electricity is really a bit of a false picture. Yes, in the short term it will be cheaper, but at some point either the electricity used for road transport will attract the tax, or conventional fuels will loose there tax in favour of direct road charging etc!
Can you really see the government dropping road fuel duty if they start to introduce wide-spread road charging? My money is on petrol duty staying roughly as it is (around 50% of the street price) and road charging being introduced as well to cover the short-fall in revenue from falling fuel sales. The Wookie said:
kambites said:
AnotherClarkey said:
ISTRC that the orginal plan for the Tesla Roadster was to have a 2 speed box but they never got it quite right for production?
I seem to remember that first gear kept disintegrating. The thing is, at low volumes, the development cost of a proper gear box is just too much. It's better to just accept the higher BOM cost of the product instead. However, when volumes climb, you can amortise the dev costs more easily, and a gerabox becomes a good idea. The best EV (REEV actually) transmission i've seen so far is the GM Volt/ampera unit. It's an absolute work of genius tbh, the internal packaging optimisation is incredible, with the epicyclic geartrain fitted inside the Emachine rotor void!
Max_Torque said:
With an Emachine powertrain, shifts should not be an issue because you have a symetrical torque capability (ie same negative torque potential as positive torque, unlike an ICE, where it is skewed >85% towards positive torque) and as such you can use that capability for machine speed control during a shift event, even a very quick one. Cars like the P1 even use the Emachine to help accelerate/deccelerate the ICE during shifting due to the high bandwidth available from the Emachines torque control loop.
IIRC from what the chap I worked with told me they were using that sort of technique but were struggling to get it synced with the shift without making it clonk or busting the box at the sort of shift times they wanted.ETA - Strangely enough I came up with the idea of using the E-machine to speed up shifts with a single clutch AMT during my thesis 6 or 7 years ago. Someone had probably thought of it before but shame I did such a rubbish job or I'd feel smug that I was ahead of the curve!
Edited by The Wookie on Tuesday 10th September 11:34
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