Graham wrote:
Now, electric cars (as we have discussed previously) suffer a further weight-of-fuel penalty compared to ICE cars. The designers manage to absorb some of it but it’s still a factor – the electric cars available generally have a significantly-reduced range compared to the ICE equivalent. With modern diesel saloon cars we got used to 700-800 mile ranges, but the ICE versions don’t even get half that. Now consider that you need (at least) 7 times as much power to take this into a truck, and the trucks can’t deal with the compromised range – so probably a lot more. Hanging around charging (which takes longer, as the batteries are that much bigger) is a non-starter for trucks.
Right, so it works only for the depot→store distribution, but not for the depot<→depot (short distance, takes time to load/unload which could be use to recharge). Got it!
gallois wrote:
Do many wish to travel more than 600km in a day on a regular basis? Or is it like the true 4 seater aircraft that one buys but is only used to full capacity every few months or less?
Equipment and infrastructure is chosen/dimensioned/built for peak usage, not regular usage. E.g. everybody wants to send an SMS or other message precisely at 00:00 on 1st of January, so the network needs to handle that load, not only the regular load. The electrical grid handles the peak when everybody comes home from the office at the same time and turns on their home equipment. The water system handles peak flow when everybody takes a shower at the same time.
The same with cars and airplanes. Even if you use your car for more than 50km, or more than 1 or 2 persons aboard, only once or twice per year to go in vacation, that’s the car you are going to choose… at least for one car per household. Unless you have easy, convenient and cheap rentals available for these once or twice, but that will probably not be available. One factor is that everyone would want a “long distance multiple occupants car” at about the same time (in France, let’s say August) so the rental companies would need huge stock… that just sits unused for long stretches. This is going to be felt in the “peak time” rental price…
gallois wrote:
That’s true but then a central power station + grid system could be used to recharge electric vehicles every 200 to 300km. You wouldn’t need the cost of a garage pumps and reservoirs plus tanker delivery etc.
But they are still carrying the power source (batteries) – a huge disadvantage. That’s the key thing that an electric train or tram doesn’t do.
Trucks don’t want to stop at all – unless limited by driving time regulations, and even then reluctanctly. They aren’t going to stop for coffee at those sort of intervals, even if you could make the trucks go that far (you couldn’t). To recharge another 200-300km in coffee-drinking time takes a huge current, even for a car. For a truck it would be simply enormous, but again it’s this funny “stop for coffee, it’s no big deal” argument. There are a couple of odd fictions that circulate with EV evangelism, one is that petrol filling stations are now apparently the nightmare blighting all our lives that we’ll gladly pay a huge sum never to have to visit again, and the other is that stopping for coffee and hanging round a car park for half an hour every couple of hundred miles on a road trip is a really fun thing to do.
If there is a future in electric trucks, it lies in them picking up power from the road like a train picks it up from the rails or overhead cable.
Silvaire wrote:
For sure the weight increases rapidly too when more batteries are on board, which is the issue with scaling aircraft up – the wing area doesn’t grow as fast as the mass. But on a ground vehicle the energy to carry batteries with rolling friction supporting the load rises only in proportion to weight and is unaffected by speed. As a result the predominant use of energy at higher traveling speeds is aerodynamic and range is increased for a scaled up larger vehicle.
The problem is carrying the weight uphill – which you’ll have to do – while maintaining any sort of sensible speed. This is the problem they had with steam locomotives – all was fine on the flat and you could pull very heavy trains quite fast, but put in even a slight gradient and the power consumption went crazy. Trucks also don’t want to use their volume for carrying batteries – they want to carry cargo – and the tractor plus detachable trailer model (which is difficult if you put batteries in the cargo space) is key to flexibility.
Interesting discussion. But based on today’s situation and I find that short-sighted.
1) We all know that the energy density of EV batteries (both as regards volume and weight) is going to increase nicely over the next 5-10 years, or even before if some revolutionary stuff comes along, who knows.. The stakes are high, and therefore the investment level too.
2) While renewables as a whole may not be a significant part of energy generation yet (although varying dramatically per country) who here is doubting that there will be a serious acceleration within the next decade? As we all know, the EU has a 1.000 billion program in place for starters. And, yes, there will be significant investment needed in the grids of all countries, so it comes at a price. But after all that, should the price of energy not go down or remain stable?
@Graham, the downhills can/could cancel out the uphills if (1) there is enough power available to climb the uphills while towing a auxiliary battery trailer and (2) the EV has regenerative capacity adequate to completely absorb the energy of a given downhill grade. I’m not familiar enough with item (2) to know if that is true or not.
In any case driving the thing is not exactly going to be an exercise in pure pleasure 
I don’t think batteries will increase in power density by a huge amount over the next ten years unless something currently unforeseen occurs. It would be nice but I wouldn’t bet anything on it.
I don’t think renewable energy production will climb greatly as a source for becoming a much higher percentage of worldwide grid output over the next 10 years. The developing world will use increasing amounts of power and it won’t be sourced from renewables. In Europe specifically, the way that fossil fuel consumption will be reduced, if it is reduced under duress over the next 10 years will be by reduced consumption. Research to take on intractable problems without the basic technology already in existence is very inefficient – this is not the space race. The effect will be reduced living standards but it is the die that has already been cast. Countries with significant nuclear or hydro power will benefit in comparison from their foresight or luck.
aart wrote:
We all know that the energy density of EV batteries (both as regards volume and weight) is going to increase nicely over the next 5-10 years
No we don’t. There is absolutely no reason that should be the case. Development has been rapid in the last decade, and now things have plateaued.
@Silvaire they could, but it’s a big ‘if’ about there being enough power to climb the hills while maintaining a reasonable speed. It isn’t acceptable for trucks to slow to e.g. 40mph because of disruption to other traffic, which is why there are no steep hills on motorways. Also trucks don’t brake on motorways, so no regenerative braking. Perhaps regenerative coasting, but that just reduces the ‘free lunch’ you get from coasting downhill so it’s zero-sum in the end. Also no steep hills on motorways, so how much off-gas coasting to trucks actually get to do? Not much I suspect.
Trams (and electric trains) don’t carry their power source with them.
The newer trams in Nice run on batteries, and recharge at the termini (and maybe at some stops en route). There is also at least one all-electric bus route, which I presume does the same thing.
I’ve been avoiding contributing to this thread since I have little to add. Electric cars are great for short journeys. For longer journeys, they are only good if your satisfaction at being “good for the planet” exceeds the negative value of increased first cost, wasted time and angst to recharge en route. For some people, this is certainly true. For most people, it isn’t.
In fact electric cars have a lot in common with “flying to get somewhere” in Europe. It CAN be done, and for some people the satisfaction at doing it exceeds the challenges. But only for a small minority.
All the stuff about “charging at home” is fine if you live in the suburbs of LA, with a big driveway and a triple garage. But taking Nice again, nearly everyone lives in apartments – true in most of mainland Europe. Cars are parked just about anywhere there is room, legal or not. Putting in a charging infrastructure would be totally impossible.
Graham wrote:
No we don’t. There is absolutely no reason that should be the case. Development has been rapid in the last decade, and now things have plateaued.
Source?
Maybe I’m an optimist by nature and only seem to stumble on articles like:
https://newatlas.com/science/lithium-metal-ev-battery-benchmark-density-stability/
Graham wrote:
If there is a future in electric trucks, it lies in them picking up power from the road like a train picks it up from the rails or overhead cable.
Graham, what about batteries for the last mile and connecting lorry to an overhead (or on the side) wire on the motorways? Like a trolleybus.
