Friday, February 10, 2023

The Problems With Electric Vehicles (continued)

from Quora:

I’ve heard people worry about charging them, and they are quite right to worry about that. The usual counter argument is that “I can always find a place to charge and they’re putting in more”.

Well yes, possibly you can always find a place to charge whilst electric cars make up three per cent of those on the roads, but as soon as electric cars become the norm and not the exception, it’s going to be problematic.

Seen from a logistical point of view the problem is in the transportation of the fuel. Liquid fuels can be placed in a tanker and distributed that way. You can’t do that with electricity. It needs to be transported down wires. If all thirty-two and a half million cars on UK roads became electric, and only one per cent want charging, that’s 325,000. That’s smaller than the number of electric cars on the roads today for sure, since it’s about 1,000,000 (give or take) but again if the number wanting charging is only one per cent, that’s only ten thousand. There are in fact about 42,000 charging points across the UK but not all cars can use all points (some are private, some need adaptors) and so just to get to one per cent of all charging needs we need another 273,000 charging points. All of them need to tap from a live grid fed by a generating station.

Well, logistically, I suppose it can be done if you are determined enough but now we run into a technical problem. Because of this:

I total is the sum of currents for those nodes. Put simply, the wires between nodes 1&2 and 7&8 have to cope with the currents of R1, R2, and R3. Between 2&3 and 6&7 they only have to cope with R2&R3 and between 3&4 and 5&6 only that of R3.

That’s the sort of idea. Multiply that several times for several nodes and much lower resistances and you’ll see that some pretty big wires are going to be needed there if you don’t want them to melt. Having both worked with and made big wires, the adjectival phrase there is “not cheap”.

Plus we’ve got a finite current source. It might be nice to think that magic electric fairies will provide us with enough current to satiate our every need, but I’ve been in electrical and mechanical since 1982 one way or another and I’ve never laid eyes on such a creature yet. The Set-on-Fire fairy though, she turns up regularly if you aren’t careful. At some point whatever’s feeding the current will be topped. There are a number of ways you can do this but the easiest is a bangy fuse.

Then we’ve got the problem of what’s generating it. Wind and solar won’t cut it. The Germans are finding that out at the moment because the Energiewendepolitik they’re pursuing has managed to shove up the cost of the electricity and the carbon footprint. Krass. Danke, Tante Angela.

This means that we are either going to have lots of nukes (Greta says no) or lots of burny/bangy things (Greta says no again) making steam to rotate some big spinnies to get some electron-juice out. More than we have now. This means that we may have cleared up local pollution by running cars with no emmisions, but we’ve transferred it to central locations instead. The only other alternative is to use our cars for essential journeys and public transport for getting about and to and from work. Which is what I do now; hey, how bloody green am I without knowing it? Well, what’s a boy to do once he’s found that out? I’ve got a day off and so down to Next it is to get my ethnic skirt and sandals.

Then we come to the battery itself. I’m having this argument that the battery materials may have changed but the technology has not. Any battery you care to name provides a flow of charge that needs a couple of plates separated by an electrolyte. The technological equivalence of the Cruickshank battery of 1802 and the shiniest newest one coming out of a factory in China is therefore so close to 1 in the working principle that arguments are moot. The fact that we can stuff a microprocessor into the Foo-Qingbig battery is neither here nor there; the principle of charge and discharge is just the same as Cruickshank used in 1802 and Planté used in 1859.

One thing that is moving the equivalence to <1 is one of the reasons the microprocessor is there. Car makers are building grace capacities into their batteries. You can do this by linking together discrete lithium cells some of which don’t get used until others deteriorate. This means for years the battery won’t have any noticeable degradations. However, once the grace is used you’ll start to see this:

which is a graph of some Cadex played about with in their labs and is pretty much what we’d expect to see from a normal test. What you’re doing when you recharge a battery is shoving a current through it backwards; the anode becomes the cathode and vice-versa. Every time you do this you cause a tiny bit of irreversible damage to the battery. Tiny bits sum up to honking great bits. What we normally find is a gentle slope to 80% capacity, then a knee, where the rate of degradation becomes sharper. Shall I tell you that there isn’t a full understanding of the complete chain of chemical reactions in how a battery operates? We know how to work the materials, but we don’t fully understand why it does what it does in the reaction process. Sometimes we get surprises. Sometimes they’re bad ones.

The act of building in grace capacities is good as far as longevity is concerned but bad as far as battery mass is concerned because it means bigger, heavier batteries and adding more mass to a vehicle means more inertia to overcome from rest. It also increases the costs of the batteries.

So it’s not that we think they’re a scam. What we do think is that the Tesla Fanboys are hyping it up too much and they aren’t looking at how vehicles are used and the logistical and technical problems if instead of ten cars on the street being electric, a hundred are.

Now, people think I’m anti-electric vehicle. I’m not. I’ve made and repaired hundreds since 1982. Electric vehicles are great for certain jobs; can’t have a reach truck in a warehouse on any other power. Trams are quick and unobtrusive and a much better ride than busses (and I’m currently having the argument about whether it’s busses or buses too, you buses-nazis can all knob off because it’s either and busses was the way I did it at school and nobody red-penned that in a grammar, so stuff it up your arses without Vaseline) with their horrible Diesel knock, and all-electric trains you can hardly tell when you’re moving, unlike Diesel-electric when you certainly know when they’re setting off.

If you are a housewife who drops the kids off at school, then does an hour or so of poncing about in Lidl and seeing to your elderly granny, an electric car (providing you can charge it at home) is great for you. You’ll have less maintenance to do on it and it may well be cheaper than petrol. If you are somebody that depends on their car for getting round multiple sites though, spread far and wide, knocking up lots of miles per day, it’s not. You are going to need to fill it with six gallons of bangy hydrocarbons to get through your day and back home.

That latter isn’t what we’re being told, though. We’re being told that electric cars are the cure for all our transport evils, and they aren’t. That’s where the objections are coming from.



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