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[Viral_Jim]

Energy released isn’t really a useful measure though is it? It’s about energy that’s used. You are actually helping to demonstrate the case for an EV, 750kw to travel <500miles is monstrously inefficient when an ev will do the same distance on circa 20-25% of that.

The argument “you have to burn it somewhere” is also far too simplistic. You need to consider the “well to wheel” pollution and emissions to decide which is better in terms of emissions. Wheel to well, a leaf emits around 40-50g/km, a golf blue motion, around 150, if you start comparing performance cars, the difference is laughable.

The Convenience question is also subjective. Today I spent nearly 20mins  at Tesco to get my 35l of unleaded. Why? Because every pump had 4 morons who all wanted 5l of petrol plus a newspaper and whatever other cr@p the shop sells. Had I had an ev, I would have got home, turned the engine off, pushed a button on the dash to open the charge flap (same as filling fossil car) got out, plugged in a cable and gone in the house. Additional time, maybe 10-15s, or 70-105s per week.

It comes back again to a question of what is actually required. The ability to take on 750kwh energy in 5mins is all nice n impressive, just totally unnecessary for 99% of the time, or 100% with a bit of casual thought.

[LC0112G]

I can load 75 litres of petrol into my car in 5 minutes Each litre on combustion releases 10kWh of energy, so I download 75 X 10 = 750 kWh in 5 minutes.

30 amps at 250 volts is 7.5 kilowatts, so charging off the 250 volt mains at 30 amps downloads 7.5 kilowatts; in an hour it downloads 7.5 kWh.

So to download the energy I pop into my Omega in 5 minutes I could charge into my electric car in 100 hours.

I suspect special domestic charging points charge at a higher rate, but at 100 amps it only comes down to 30 hours. 100 amps necessitate rewiring to house and garage, possibly the street and grid if we all do it, and building more power stations.

Think about it, check my sums. Or conside: instead of burning all that petrol in cars, you have to burn it at the power stations, and transmit the power to all the charging points.

Whist I agree with the jist of the post, the numbers need amending a bit.

Yes you can fill your Meega with 75L in 5 minutes, and yes at 10Kw/l ish that's 750Kw. But, a good internal combustion engine can only extract about 15% of the available energy and convert it into work. So of that 750Kw, only about 112Kw actually moves you forward. The rest goes in heat, noise and un-burnt fuel.

On the other hand, electric motors are much more efficient - up around 80%. So to match the 112Kw extracted from the petrol, your battery would have to discharge about 140Kw. Therefore assuming a 100% charging efficiency (unlikely) charging from a 7.5Kw source will take about 19 hours, not the 100 you state. Still far too long though.

Electricity produced in power stations from fossil fuels is about 30% efficient. Therefore to generate 140Kw of mains power you need to burn 470Kw of fuel - which is around a 40% saving in fuel burnt per mile travelled (ignoring power distribution and charging losses).

[Nick W]

In 2018, both Kia and Hyundai will release models with a real world range of 260-300miles in the uk (weather dependent). So it’s hardly stuff of the distant future.

One of our directors is a NED at Dyson and their stated aim is a 1000 mile range ev by 2022. In a relatively short period of time evs will be quicker, more reliable and equally/more convenient than fossil powered cars.

I think there is a great temptation to confuse noise with excitement and unreliability with character when it comes to motor vehicles.

They're already quicker, more reliable and economical than IC cars. The charging technology and infrastructure doesn't measure up to the (already paid for) network of filling stations. But before WW1 when there was nothing to choose between IC and electric, you bought petrol in cans from a pharmacy. The war led to a massive improvement in engines, but not in batteries. And they're still the problem; there isn't yet an effective way of making a battery with a large capacity that's small in size, lightweight and quick to charge - let alone one that's affordable and ecologically sound. The recent improvement in electric vehicles came partly from LiOn batteries, and mostly from electronic control of them and the motors they power. Those are Tesla's real business, the cars are just a means to an end.


Generating energy remotely has got to be more efficient(and therefore with fewer emissions) than releasing it locally. And fuel has a whole supply chain that never gets mentioned; we dig it out of the ground, ship it around the world, change its form in refineries, store it, ship it, store it again before it's sold to the end user. Who just burns it to use about 20% of the energy released! That's an appalling waste of precious resources that have better uses, especially as we don't have to generate electricity like that.


And as mentioned, the frequently mentioned 'character' of IC engines are the waste products that we ought to be eliminating. And as car enthusiasts, we're weird - most car users consider them only as an expensive appliance. I've written this before, but altering the way we power vehicles is just papering over the cracks - changing the way we use them is the real answer. But that's a social change, and forcing those never ends well.

[terry paget]

Let's not confuse kilowatts with kilowatt hours, chaps. A kilowatt (kW) is a rate of power, and a kilowatt hour (kWh) is a quantity of energy, a kilowatt for an hour.

Sure, burning fuel in a car is only about 15% efficient, but a coal or oil powered power station is only about 30% efficient  Electrical power distribution incurs losses too.

I wonder why we spend vast sums converting our railways from diesel to electric haulage. We should burn the oil in the locomotive, not in a remote power station.
.

[Marks DTM Calib]

As the consultant injected anaesthetic into my head before digging out a biopsy, she enquired how I had collected the strange  pattern of head injuries. By bashing me head while working under my six Omegas, I told her.

She replied she had never heard of such a car, was it very old? Not very, I said.

She went on to tell me that a colleague is buying an electric car with a 250 mile range. I told her there was no such car, nor ever will be. All electric cars are basically mik floats, and should not stray far from their bases. They are fashion items, bought by rich fools who believe they are saving the environment by not emitting noxious gases, unaware that the electricity they use is generated by a nearby fossil fuel power station also emitting noxious gases into the atmosphere.

She sent me on my way with written instructions on how to treat the wound she had just created, and to consult my GP if it turned nasty.

Most of the Tesla Range will do that

On paper, in reality, far from it (sadly)

[LC0112G]

The war led to a massive improvement in engines, but not in batteries. And they're still the problem; there isn't yet an effective way of making a battery with a large capacity that's small in size, lightweight and quick to charge - let alone one that's affordable and ecologically sound. The recent improvement in electric vehicles came partly from LiOn batteries, and mostly from electronic control of them and the motors they power.

That's because the required improvements to batteries cannot and will not happen. The physics is well understood. It's just as likely that IC engines will double in efficiency as it is that batteries will double in capacity, (although dividing a 0% chance by a different 0% chance is always iffey). You might be able to squeeze another few percent out of either technology, but there is zero chance of them doubling or more.

Generating energy remotely has got to be more efficient(and therefore with fewer emissions) than releasing it locally. And fuel has a whole supply chain that never gets mentioned; we dig it out of the ground, ship it around the world, change its form in refineries, store it, ship it, store it again before it's sold to the end user. Who just burns it to use about 20% of the energy released! That's an appalling waste of precious resources that have better uses, especially as we don't have to generate electricity like that.

The distribution losses of electricity aren't negligible either. In a small country like the UK losses are about 8%. In a large country like the US they're up around 15%. And battery charging isn't perfect either. Tesla claim 92% efficiency - users report more like 80%. So for every 100Kw generated at the power station (in the UK), 92Kw reaches your house, and (at most) 85Kw ends up charged into your battery. If the motors in a Tesla are 80% efficient, then 68Kw ends up being converted into work moving you forwards. The total efficiency from power station to destination is therefore at best 68%.

The supply chain for fossil fuels is basically the same whether you burn it in a remote power station or in your local IC engine. We don't burn much oil (8%) or coal (8.5%) anymore, but about 40% is gas. Much of this is imported in super tankers from the middle east, so has similar transport costs to petrol burnt in cars. Gas has a 20% higher (mass) energy density than petrol so you can extract more useable energy from it than from the equivalent mass of oil/coal. But petrol has a better volumetric density - more bang per litre and so is better suited to mobile applications where you have to move the fuel with the consuming device. The only real difference is in the transport of the fuel from the refinery to the petrol station

We could generate the electricity by Nuclear, but for various reasons that's currently only about 20% of UK generation. Renewables make up the remaining 25% or so and won't be in any position to displace gas in the foreseeable future.

And as mentioned, the frequently mentioned 'character' of IC engines are the waste products that we ought to be eliminating. And as car enthusiasts, we're weird - most car users consider them only as an expensive appliance. I've written this before, but altering the way we power vehicles is just papering over the cracks - changing the way we use them is the real answer. But that's a social change, and forcing those never ends well.

Yes - and won't happen.

[Field Marshal Dr. Opti]

In 2018, both Kia and Hyundai will release models with a real world range of 260-300miles in the uk (weather dependent). So it’s hardly stuff of the distant future.

One of our directors is a NED at Dyson and their stated aim is a 1000 mile range ev by 2022. In a relatively short period of time evs will be quicker, more reliable and equally/more convenient than fossil powered cars.

I think there is a great temptation to confuse noise with excitement and unreliability with character when it comes to motor vehicles.

 Jimmy.....Noise is an essential part of the excitement.

 Are you seriously telling me that a Ferrari Daytona or AC Cobra with a 7 litre  lump of Detroit V8 up front would be just as exciting if it made the same noise as one of those little light blue spaz chariots from the seventies?......

[Viral_Jim]

That's because the required improvements to batteries cannot and will not happen. The physics is well understood. It's just as likely that IC engines will double in efficiency as it is that batteries will double in capacity, (although dividing a 0% chance by a different 0% chance is always iffey). You might be able to squeeze another few percent out of either technology, but there is zero chance of them doubling or more.

Seems quite a bold statement. Particularly given the current promising research into Nanowire batteries at Uni of California and the various big companies' (BMW, Dyson & others) research into solid state batteries. The current lithium ion tech isn't much developed from its original 1989 guise, largely because no one had an application that required it to be better than it is. That's now changing and battery technology will inevitably move forward with it.

[Field Marshal Dr. Opti]

In 2018, both Kia and Hyundai will release models with a real world range of 260-300miles in the uk (weather dependent). So it’s hardly stuff of the distant future.

One of our directors is a NED at Dyson and their stated aim is a 1000 mile range ev by 2022. In a relatively short period of time evs will be quicker, more reliable and equally/more convenient than fossil powered cars.

I think there is a great temptation to confuse noise with excitement and unreliability with character when it comes to motor vehicles.

What could be more character building than to fix an old MGB or TR6 by the side of the road in pissing pain with no more than a spanner and a set of feelers?

 

[Nick W]

LC0112G:


We're agreeing with each other! I would have said that it's chemistry not physics that prevents any radical improvements to batteries, delivery of electricity and IC engines(I strongly suspect the big improvement that full management gave 30 years ago is the last one we'll see), but the point is the same: any improvements to either will be hard won and incremental at best.


What I really resent is that we're constantly assured that extremely complex  problems have easy magic-bullet solutions: renewables for electricity, 'zero emission' electric cars, Brexit, wars in the middle-east, privatisation, build a wall, etc etc. And they'll ALL be affordable. Hurrah!!! Unfortunately, there are plenty of stupid and/or ignorant people to encourage such mendacity. Many of them are the politicians we select to govern us.


I do see a change in vehicle usage(energy usage really) happening but it's not going to be the worst change, as it will  caused by something disastrous. Hopefully not in the next 30odd years.

[LC0112G]

I wonder why we spend vast sums converting our railways from diesel to electric haulage. We should burn the oil in the locomotive, not in a remote power station.

Most Diesel locomotives are actually Diesel-Electric. They burn the Diesel in an engine which powers a generator which generates electricity and powers electric motors connected to the wheels. They are in effect huge HEV's. It's difficult to produce a mobile system that is cheap, efficient, reliable, relatively light and capable of propelling a train at much more than 100 miles an hour. 

Once you decide you want a system that can go at 150+ mph the only option is to remove the engine and generator from the train, generate the electricity remotely, and then wire up the tracks/catenaries.

[Nick W]

I wonder why we spend vast sums converting our railways from diesel to electric haulage. We should burn the oil in the locomotive, not in a remote power station.
.

Two things:


As trains run on fixed tracks, they can be plugged into the mains all the time. Hybrids are a bodge.


There's only a limited supply of oil and multiple uses for it, so we should only be burning oil when there isn't a better way of achieving the same result. That hasn't happened for road vehicles yet, but did sometime ago for generating electricity. We've decided that we don't like it as a solution, and so are stuck with the half-arsed ones.

[LC0112G]

Seems quite a bold statement. Particularly given the current promising research into Nanowire batteries at Uni of California and the various big companies' (BMW, Dyson & others) research into solid state batteries. The current lithium ion tech isn't much developed from its original 1989 guise, largely because no one had an application that required it to be better than it is. That's now changing and battery technology will inevitably move forward with it.

No. The energy storage capacity of virtually all substances has been known for years :

https://en.wikipedia.org/wiki/Energy_density

The only known substances with better energy capacity per mass/volume than chemical/burnable fuels are nuclear. Any battery tech you come up with will always be at least an order of magnitude worse than fossil, meaning it has to be much heavier and much larger to be capable of storing the same amount of useable energy. Useable energy from (charged) batteries is 5 ish times better than fossil (15% vs 80%), but with energy densities 40-50 times worse you've got a net 10 fold difference to make up.

So until someone produced the first Dilithium crystal powered engine I stand by my statement.

[Viral_Jim]

No. The energy storage capacity of virtually all substances has been known for years

But again, that's only the negative half of the story.

If you solve the charging issue, the energy density available is more than sufficient. Hypothetically, if you could input say 10% of a battery's capacity per second of charge (not currently possible or likely, but illustrative) you could recharge a 250mile battery while sat at the traffic lights, so energy density would then become a non-issue. 

[LC0112G]

LC0112G:


We're agreeing with each other! I would have said that it's chemistry not physics that prevents any radical improvements to batteries, delivery of electricity and IC engines(I strongly suspect the big improvement that full management gave 30 years ago is the last one we'll see), but the point is the same: any improvements to either will be hard won and incremental at best.


What I really resent is that we're constantly assured that extremely complex  problems have easy magic-bullet solutions: renewables for electricity, 'zero emission' electric cars, Brexit, wars in the middle-east, privatisation, build a wall, etc etc. And they'll ALL be affordable. Hurrah!!! Unfortunately, there are plenty of stupid and/or ignorant people to encourage such mendacity. Many of them are the politicians we select to govern us.


I do see a change in vehicle usage(energy usage really) happening but it's not going to be the worst change, as it will  caused by something disastrous. Hopefully not in the next 30odd years.

Ahh Ok - I misread your meaning. Chemists and Physicists only differ by orders of magnitude. Chemists work out how to blow up buildings, factories etc. Physicists work out how to blow up the world/universe.