EVs and chargers

I’m going to guess something in the ballpark of 2-3kW.

Low level mathematics: 16 × 250 = 4,000 (good old VA)

Yup. People who I know don’t have a big family (lots of children) turn up to work in urban tanks. It’s ridiculous. And there’s a woman in the village that takes her car to visit her sister in law. That’s across the road and about 100m down.

I live next door to the school turn around, Moet the cat (RIP) used to lie in the muck and dust in the road in summer safe as houses, school days the mummies and daddies (and grans/gramps) deliver the kids in cars from all parts of the village “because it’s dangerous with all the cars” – well, Dur!!
Then there’s the “weight watchers” evenings with cars delivering kids that need to lose weight that they could lose quite easily if they walked to and from school, etc.

We’re not supposed to think where the electricity comes from

Well, I suppose there’s a good chance that someone in a currently oil rich country will realise that production of synthetic fuel like H₂ is energy intensive and if you had a resource above the sand (like sunshine) you could dominate the synth fuel market.

Chopped up maise is usually put into a clamp – making silage around here.

I’m going to guess something in the ballpark of 2-3kW.

Low level mathematics: 16 × 250 = 4,000 (good old VA)

I wasn’t talking about the capacity of the plug (3680W here, 230V!), I was talking about the draw of the car when plugged in. You can probably work out from the rating of the battery and how long it takes for a full charge, but I don’t feel like trying to track down all the specs. There’s just something strange when it’s easy to find out the rating of a washing machine (2400W max) or a fridge (135W) but that of an electric car seems rather harder to determine.

Let’s assume it’s 2.5kW. Well, I currently pay €0,38/kWh (total cost to me). Which means charging the car for an hour would cost €0,95. A full seven hour charge would be €6,65. If I had to do that every other day, then it would potentially cost me €46,55 for a fortnight. Which is about TWICE what I just paid (this evening) to fill my tank with diesel, even at today’s prices.
If 2kW, that’s €0,76/h and €37,24.

Granted, I would be driving ~50ish km rather than 65, so it won’t need a full charge, and obviously my price per unit including taxes and supply costs would go down the more units I use, but I still not sure if there is any economic benefit to me to have an EV, especially given the price and the finite life of the battery. I don’t think it’s useful to save money each month in order that, after 3-4 years I would have enough to buy a new battery in order to go to work to save money to buy a new battery in order to go to work to [repeat until dead].

These are off-the-top-of-my-head calculations, but to be honest I can much better budget fuel. It’s twenty euros into the tank as and when it needs it, not the electricity company saying “you owe us two hundred and we want it within two weeks”.

Anyway… I could make better calculations if I wasn’t guessing so much.

Anyway… I could make better calculations if I wasn’t guessing so much.

The ballpark figure for electric cars is “something between 12kWh and 20kWh per 100km” – during summer, winter is a bit (or a lot, highly dependant on temperature outside and inside) worse. For comparison, my car needs 5-6l/100km, which translates to 40 to 50 kWh. Which nicely illustrates Carnot.

Charging efficiency is quite good when operating with a proper wallbox providing 11kW or 22kW, but gets a lot worse (lower than 80% IIRC) when using your average 2.4kW plug.

I wasn’t talking about the capacity of the plug (3680W here, 230V!), I was talking about the draw of the car when plugged in

Not much point in fitting a 16A plug on something that doesn’t even draw 13A

The ballpark figure for electric cars is “something between 12kWh and 20kWh per 100km” – during summer, winter is a bit (or a lot, highly dependant on temperature outside and inside) worse.

A colleague was quite alarmed when he noted how much the just barely sub-zero temperatures affected the start of journey charge level.
I’m thinking that it might take much more extreme weather to affect things if it was an H₂ fuelled car.

I’m thinking that it might take much more extreme weather to affect things if it was an H₂ fuelled car.

If the hydrogen feeds a fuel cell, the situation is no different from batteries because there’s no significant waste heat to recover to heat the car in cold weather.

If the hydrogen feeds a heat engine, it will be much less efficient to start with.

The thing that makes it better is to have a heat pump in your car to heat efficiently in winter. My car has one. It also cools in summer of course.

A colleague was quite alarmed when he noted how much the just barely sub-zero temperatures affected the start of journey charge level.

It’s usual for an electric car to pre-heat itself if necessary, timed for your departure, powered by mains if you leave it plugged in.

I’m fortunate to have a garage, so the car will never start quite that cold.

Rapid charging is lousy for the battery.

You might think so, but if you do a few calculations, you will notice that even with today’s fastest chargers (for Germany, that’s currently the 300kW ones), the energy that flows into every cell is actually not what we know as “rapid charging”, but actually “normal charging”. The secret of today’s high capacity car batteries is the insane number of cells they are built of.

And if your battery is good for a 600km range, the limited rapid charging cycle numbers for today’s batteries shouldn’t frighten you in any case – 1000 cycles is easy-going, and I doubt that the rest of the car will survive those 600,000km.

So rapid charging is only a problem for plug-in hybrids or very cheap micro cars with their small capacity batteries. Consequently they won’t go over 50kW, some don’t even allow more than 11kW.

Not much point in fitting a 16A plug on something that doesn’t even draw 13A

Our regular plugs are rated 16A – this thing: https://www.amazon.fr/dp/B00GWP9X6O/

when operating with a proper wallbox providing 11kW or 22kW

Uh-huh. You know my tariff maxes out at 9kW right? ;)

For comparison, my car needs 5-6l/100km

Mine just did 355km and I put in 12.50 litres, which cost €21,24.
So what is that, 3.5l/100km or something? 30kWh?

Bear in mind, also, that I’m talking small EVs as well, like this: https://www.aixam.com/en/aixam-configurator?gamme=2&vehicule=9&moteur=4&modele=38&coloris=208 (don’t look at the price, that’s the other primary reason why I’m not especially interested)

The problem with hydrogen is that the only way we know of generating it cleanly is electrolysis of water, but, when you put in real numbers for power consumed versus power delivered to the wheel, it’s very inefficient – you have to compress it and distribute it.

So there’s no visible way to make it cost competitive with battery storage of the same electricity.

I doubt that the rest of the car will survive those 600,000km.

The general wisdom is that batteries will outlast the car these days. This surprises many people whose knowledge hasn’t progressed since the earliest days of battery-powered cars (and the FUD put about by many).

In America, the expectation is that batteries from end-of-life cars will be used for grid-scale storage.

the only way we know of generating it cleanly is electrolysis of water

Brilliant. Something else we’ll bugger up.

The water on this planet isn’t new. That glistening glass of Evian? It’s been through thousands of people, millions of animals, and the odd diplodocus or two.
The water on this planet has been here from near enough the start, in a continual cycle that is both oceans and weather and fundamental in most life on this planet.

One doesn’t just create water. You can’t bash a couple of hydrogen atoms into an oxygen one and say job done, so it’s worth considering that if we start extracting hydrogen from water, then that’s pretty much an irreplaceable resource. It’s not like a vanishing lake that evaporates into the sky and falls as rain someplace else, this is gone. As in nearly 4.5 billion years of being a part of damn near everything, until some twat decides they want to burn it away to make a school run that their kids could easily walk.

Yeah. Bye bye frying pan, hello red embers.

if we start extracting hydrogen from water, then that’s pretty much an irreplaceable resource. It’s not like a vanishing lake that evaporates into the sky and falls as rain someplace else, this is gone.

Come on, now, Rick. When the hydrogen is used in a fuel cell or in an ICE, the reaction that occurs is the oxidation of the molecular hydrogen to water. You have a closed cycle.

In America, the expectation is that batteries from end-of-life cars will be used for grid-scale storage.

Which means that Americans cannot use a calculator, because the capacity will not be enough for meaningful storage capacity.

For Germany, the calculation was that at least 100 TWh of storage will be needed when “Energiewende” shall succeed (i.e. 100% CO2 neutral electricity – NOT 100% CO2 neutral society!). Now how many big 100kWh car battery packages will you need for the US…

But of course it depends on what you really mean by “grid-scale”. If you only want to have some stabilization of your grid to keep some of your traditional power generation in a more efficient operation window, and you want to avoid throwing away too much of your PV generation, the capacity you need is a lot less than for full CO2 neutrality without nuclear.

The water on this planet isn’t new.

Even ignoring that the H2 will end up as H2O after the cycle as Chris rightly stated…just do the calculation: how much water is there on planet earth, and how much H2 would be needed to store the whole energy need for say a year? You will find out that the amount of H2O needed for all that H2 would really be only the “drop in the ocean”.

So what is that, 3.5l/100km or something? 30kWh?

Your car is Diesel powered, so more like 35kWh. You know, there is more C in Diesel than in Gasoline, which means that Diesel energy density is higher (and CO2 emissions per litre is consequently higher).

Are electric vehicles batteries going to last longer that Laptops?

Is 5 years the length of time a USA vehicle lasts :-)

You have a closed cycle.

So… we take water, split it off into hydrogen and oxygen, burn it, and it makes water, suggesting that the loop remains closed as you say.

Okay, so where does the energy come from?

would really be only the “drop in the ocean”.

Indeed it would be merely a drop in the ocean. However, I wouldn’t put it past companies to do something stupid like process fresh water because it’s cheaper / less corrosive.

Salty water we have in abundance. Fresh water is already suffering from the effects of industry.

Okay, so where does the energy come from?

Electrical power derived from sunlight (solar cells), solar heating (plain old water warming/boiling on dark surfaces)…
Clean, renewable energy source.

However, I wouldn’t put it past companies to do something stupid like process fresh water because it’s cheaper / less corrosive.

I would suggest that the largest user of the hydrogen would be industry, who for the first time in history would suddenly be a source of sizable volumes of clean water. Gasp!
The desalination by product might well be an alternative to digging salt out of the ground.

I think Rick was saying that you don’t get something from nothing.

You burn Hydrogen – heat is generated – and you get a small amount of water as a bi-product.

The German Air ships were a big user of Hydrogen (weren’t able to obtain a safer gas from USA)

Note big fires when Airships burnt.

Down here the Water party are telling about building a De Sal plant at Par – Hmm

Rains a bit down here :-))

Power to do it from ??

Power from Sun Nuclear – long way off.

Build windmills in Cities – they can listen to the Womp Womp Womp – as the Giant blades turn!

I think Rick was saying that you don’t get something from nothing.

That’s what I was saying. You can’t get the same water out as is put in, because if you were, you’re extracting the energy for combustion from….?

they can listen to the Womp Womp Womp – as the Giant blades turn!

When you’re close enough to hear the blades, you’re close enough to hear the fweeeeeee of the turbine. That, to me, is a much more annoying noise.

I think Rick was saying that you don’t get something from nothing.

There’s this really big nuclear furnace about 93 million miles away, chucking heat and light in all directions, including here.

Harnessing some of it is an activity that life on Earth has been doing with varying degrees of efficiency for millions of years.
Using a bit to split water temporarily is just another facet of that capture and use.

Rains a bit down here :-))

Power to do it from ??

Rainwater running downhill through a turbine ??

You can’t get the same water out as is put in, because if you were, you’re extracting the energy for combustion from….?

Same hydrogen, different (but equivalent amount) Oxygen
and the energy is from that big nuclear furnace, sitting at a safe(ish) distance

You could use Arcimedes screw (lower power output) in the bottom of rivers – perhaps making use of tidal effect.

Could be made quite discreet.

No giant pit dug – filled with concrete – to support wind towers – some of which are huge.

[Edit]

Years ago down here water was used as a power source – saw mills flour mills etc.

Some tried wind – but it wasn’t too popular.

Piles of windmills being built – but not much use of water power.

Power from Sun Nuclear – long way off.

You should note that, in effect, using hydro-electric facilities is essentially utilising solar energy at one remove.

The rain, that falls on higher reaches, was evaporated to become clouds, that rained, by solar heating

Edit Hydro power even cheats a little and gets gravity in on the power generation