They're reasonably priced, considering (though still outside the average reach of course) and there's a 450km version too. Apparently 50 have arrived in the UK so go and test one for us, Pepperman!Pepperman wrote:emordnilap wrote:The latest Tesla promises 300km on a charge, which makes it a good car for most people in Ireland. In fact, it'd do for most people in these isles - that'd be a fair whack of driving without a break.Pepperman wrote:Fair enough. I've never thought that pure EVs are appropriate in all places (although I suspect they are appropriate in 99% of places).
Completely but there's always someone who wants more than that so they'll be catered for in some way. Tesla does achieve great range but it does that using a massive battery which puts it out of reach of most.
Are we on the brink of an electric car revolution?
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- emordnilap
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I experience pleasure and pains, and pursue goals in service of them, so I cannot reasonably deny the right of other sentient agents to do the same - Steven Pinker
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This is a good alternate viewpoint.Pepperman wrote:Looking at it another way, we have 32m (erk..!) cars on the road at the moment driving about 8000 miles each. Assume 0.3kWh/mile (taking into account charging efficiency) and you've got about 75TWh. For comparison, UK electricity demand is just over 300TWh so electrifying all cars is about 25% of final demand.
Using:
http://www.racfoundation.org/motoring-faqs/mobility
The figures I got for national usage almost certainly included all the cars (and probably some electrically powered trains).At the end of March 2017 there were 37.5 million vehicles licensed for use on the roads in Great Britain, of which 31.1 million were cars. In the year to March 2017 the stock of vehicles increased by 2.2 per cent. This is the sixth consecutive quarter that year-on-year increases have exceeded 2 per cent. This also occurred in two quarters of 2014 but had not previously been seen since 2005
Using a bottom up calculation, therefore, would point something over 100TWh.
Electric vehicles do have the potential to provide a material amount of smart storage which can cope with more unpredictable supply.
However, I think the 10% figure is low. It would be good to identify the discrepancy between the national figures and the aggregated bottom up figures. That may arise from a greater comparative efficiency in kWh per mile.
On the other hand it depends upon how many Wh per mile. Looking at the tesla forums it can be as high as 400.
At least we are in the right ballpark on this.
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The 10% figure is based on some % of the fleet being EV (70% of new cars by 2040). Its also based on electricity demand in 2040 which is expected to be higher due to increased electrification of heat. I like to compare it against the current grid as it makes more sense to me. I think both estimates are probably consistent.johnhemming2 wrote:However, I think the 10% figure is low. It would be good to identify the discrepancy between the national figures and the aggregated bottom up figures. That may arise from a greater comparative efficiency in kWh per mile.
On the other hand it depends upon how many Wh per mile. Looking at the tesla forums it can be as high as 400.
At least we are in the right ballpark on this.
Teslas aren't your average EV. There are three EVs (Zoe, i3 and Leaf) which outsell the Model S and all three of those have much lower consumption:
http://www.nextgreencar.com/electric-cars/statistics/
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It is still slightly surprising to me that electrifying road transport can be that "easy" (it's not easy, it's a huge amount of electricity, but I think it's considerably less than is generally perceived).
Here is road transport fuel consumption (million tonnes of fuel) in 2015:
Cars 22.40
LGV 5.76
HGV 6.23
Buses 1.18
Motorcycles 0.17
I'm pretty happy with my estimate of 25% of current demand for electrifying cars (I reckon to within +/- 5%), so the above figures suggest it might be another 5%-10% for vans and about the same again for trucks. Rail diesel demand is 1% of total transport demand so will be lost in the noise. I can't see how it can be much more than 50% of current demand.
Vehicle internal combustion engines are only 20% to 25% efficient so the actual energy needed to move the vehicle is only a fifth to a quarter of what is actually consumed. With electric vehicles there are some charging losses (say 10% to 15%) but any conversion losses from the battery to vehicle motion are wrapped up in the kWh/mile value already.
Note that I am obviously ignoring the primary energy inputs that go into the power station but that's ok because we're talking about electricity demand here, not primary energy demand.
Here is road transport fuel consumption (million tonnes of fuel) in 2015:
Cars 22.40
LGV 5.76
HGV 6.23
Buses 1.18
Motorcycles 0.17
I'm pretty happy with my estimate of 25% of current demand for electrifying cars (I reckon to within +/- 5%), so the above figures suggest it might be another 5%-10% for vans and about the same again for trucks. Rail diesel demand is 1% of total transport demand so will be lost in the noise. I can't see how it can be much more than 50% of current demand.
Vehicle internal combustion engines are only 20% to 25% efficient so the actual energy needed to move the vehicle is only a fifth to a quarter of what is actually consumed. With electric vehicles there are some charging losses (say 10% to 15%) but any conversion losses from the battery to vehicle motion are wrapped up in the kWh/mile value already.
Note that I am obviously ignoring the primary energy inputs that go into the power station but that's ok because we're talking about electricity demand here, not primary energy demand.
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- emordnilap
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So there you are. And Shell are getting out of tar sands and "into renewables" (and attempting to block the EU's moves to electric cars), though they're big into gas and biofuels.A Shell spokesman told Bloomberg the CEO will get a plug-in Mercedes-Benz S500e in September, while the Chief Financial Officer “already drives a BMW i3 electric car.�
Source
I experience pleasure and pains, and pursue goals in service of them, so I cannot reasonably deny the right of other sentient agents to do the same - Steven Pinker
A growing trend. My wife works at a bank, and of the 6 charging stations available for employees who drive electric, 5 are filled, day in and day out.emordnilap wrote:So there you are. And Shell are getting out of tar sands and "into renewables" (and attempting to block the EU's moves to electric cars), though they're big into gas and biofuels.A Shell spokesman told Bloomberg the CEO will get a plug-in Mercedes-Benz S500e in September, while the Chief Financial Officer “already drives a BMW i3 electric car.�
Source
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- Potemkin Villager
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Welcome Johnny, I wonder have you been lurking for long?johnny wrote: A growing trend. My wife works at a bank, and of the 6 charging stations available for employees who drive electric, 5 are filled, day in and day out.
I wonder how many folk at the bank drive to work rather than use public transport and why (I guess it is not in central London) ?
Overconfidence, not just expert overconfidence but general overconfidence,
is one of the most common illusions we experience. Stan Robinson
is one of the most common illusions we experience. Stan Robinson
- emordnilap
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So it's coming: convoys of lorries driven by one human being. Touted as 'cutting congestion' !!!
This is to divert attention from:
• making more money for haulage companies
• getting rid of up to two thirds pesky drivers, who need paying, the cheeky sods (truck driving was in the most common jobs in 28 US states in 2014)
• the taxpayer is paying for trials
• race to the bottom for remaining lorry drivers
• justification for motorway extension and upgrading (paid for by...)
• less freight by rail
• easy challenge for hackers
This is to divert attention from:
• making more money for haulage companies
• getting rid of up to two thirds pesky drivers, who need paying, the cheeky sods (truck driving was in the most common jobs in 28 US states in 2014)
• the taxpayer is paying for trials
• race to the bottom for remaining lorry drivers
• justification for motorway extension and upgrading (paid for by...)
• less freight by rail
• easy challenge for hackers
I experience pleasure and pains, and pursue goals in service of them, so I cannot reasonably deny the right of other sentient agents to do the same - Steven Pinker
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If I have understood correctly, each HGV will still have a driver to steer, and to take control in an emergency.
The first vehicle will be driven just like any other, but the second and third vehicles will have braking and acceleration under automatic control, controlled by both the lead vehicle and by a distance sensor that maintains a modest gap.
No savings in wages.
The gain is less fuel used, due to the second and third vehicles closely following the one in front, and less road space taken up.
Without any reliance on human reaction times, the following trucks can slow or stop more quickly and thus run much closer together.
If the human driver in the leading vehicle brakes, then the following vehicles brake within a small fraction of a second.
No matter how harsh or gentle the braking of the front vehicle is, the following ones should brake at the same rate and remain the same distance apart.
The main pitfalls are firstly what if the front vehicle makes an almost instant stop by colliding with something, a pile up seems unavoidable in that case.
And secondly, the drivers of the following vehicles have less to do and might have trouble staying alert.
OTOH, few if any human drivers leave enough room to stop if the vehicle in front makes an unexpected stop.
The first vehicle will be driven just like any other, but the second and third vehicles will have braking and acceleration under automatic control, controlled by both the lead vehicle and by a distance sensor that maintains a modest gap.
No savings in wages.
The gain is less fuel used, due to the second and third vehicles closely following the one in front, and less road space taken up.
Without any reliance on human reaction times, the following trucks can slow or stop more quickly and thus run much closer together.
If the human driver in the leading vehicle brakes, then the following vehicles brake within a small fraction of a second.
No matter how harsh or gentle the braking of the front vehicle is, the following ones should brake at the same rate and remain the same distance apart.
The main pitfalls are firstly what if the front vehicle makes an almost instant stop by colliding with something, a pile up seems unavoidable in that case.
And secondly, the drivers of the following vehicles have less to do and might have trouble staying alert.
OTOH, few if any human drivers leave enough room to stop if the vehicle in front makes an unexpected stop.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
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