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The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 6:12 pm
by lpm
bjn wrote:
Sun Jan 09, 2022 3:36 pm
It was a proof of concept.

You would cover some proportion of annual miles in a vehicle with a few square meters of solar panels on the roof. Whether that’s the best use of the solar panels or the money is the pertinent question.

Given sufficiently cheap solar panels it might be a thing. Something like perovskite panels, which in theory should be much cheaper, but are less durable than silicon cells, might be useful. Cars get junked well before a static solar panel does.
Surely solar panels can't cope with weather like modern car paintwork?

It has to travel at 70 mph in rain and hail, deal with bird droppings and falling twigs, and will get salty spray this time of year.

It must be so much cheaper and easier to put that solar area on a roof. Or as canopies on the recharge zone of the motorway services, which is already happening. We should concentrate on solutions already working.



* I've self split this from "Death of..." as there's enough EV volume of posts to sustain separate threads.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 6:18 pm
by WFJ
lpm wrote:
Sun Jan 09, 2022 6:12 pm
bjn wrote:
Sun Jan 09, 2022 3:36 pm
It was a proof of concept.

You would cover some proportion of annual miles in a vehicle with a few square meters of solar panels on the roof. Whether that’s the best use of the solar panels or the money is the pertinent question.

Given sufficiently cheap solar panels it might be a thing. Something like perovskite panels, which in theory should be much cheaper, but are less durable than silicon cells, might be useful. Cars get junked well before a static solar panel does.
Surely solar panels can't cope with weather like modern car paintwork?

It has to travel at 70 mph in rain and hail, deal with bird droppings and falling twigs, and will get salty spray this time of year.

It must be so much cheaper and easier to put that solar area on a roof. Or as canopies on the recharge zone of the motorway services, which is already happening. We should concentrate on solutions already working.



* I've self split this from "Death of..." as there's enough EV volume of posts to sustain separate threads.
It would also be a totally useless waste of money for anyone who keeps their car in a garage, covered car park or on the street surrounded by high buildings. Most cars spend most of their time not being driven.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 6:47 pm
by dyqik
WFJ wrote:
Sun Jan 09, 2022 6:18 pm
lpm wrote:
Sun Jan 09, 2022 6:12 pm
bjn wrote:
Sun Jan 09, 2022 3:36 pm
It was a proof of concept.

You would cover some proportion of annual miles in a vehicle with a few square meters of solar panels on the roof. Whether that’s the best use of the solar panels or the money is the pertinent question.

Given sufficiently cheap solar panels it might be a thing. Something like perovskite panels, which in theory should be much cheaper, but are less durable than silicon cells, might be useful. Cars get junked well before a static solar panel does.
Surely solar panels can't cope with weather like modern car paintwork?

It has to travel at 70 mph in rain and hail, deal with bird droppings and falling twigs, and will get salty spray this time of year.

It must be so much cheaper and easier to put that solar area on a roof. Or as canopies on the recharge zone of the motorway services, which is already happening. We should concentrate on solutions already working.



* I've self split this from "Death of..." as there's enough EV volume of posts to sustain separate threads.
It would also be a totally useless waste of money for anyone who keeps their car in a garage, covered car park or on the street surrounded by high buildings. Most cars spend most of their time not being driven.
Or even has trees shading their driveway.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 6:56 pm
by bjn
As I said, might not be the best use of a solar panel, unless they were stupidly cheap. I used to park a car on the street in suburban Sydney, which would be a better proposition thank parked on a street in urban London.

Solar panels do need to be just as robust as a car roof, being put on roofs and left in the rain and all. Current panels have a lifetime of 25 years or so, which means they are more likely robust than a car roof.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 7:04 pm
by lpm
Fundamentally electricity is dead easy to transport. No need for thousands of tankers. Easier than for water and turning on a tap.

So no real need to transport electricity ourselves. We don't take much water with us when travelling, we just get it from taps on the way and at our destination.

Generating power on the move feels like it comes from the current temporary obsession with range and lack of chargers. It will look silly in a decade. A single minute's worth of recharging.

My guess is most people will pick a car with 200 miles range and very fast recharging, rather than pay more for bigger batteries and gimmicks.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 7:16 pm
by shpalman
Is there any particular reason why a car with less range would charge faster in terms of km range per minute of charge? Smaller battery with less internal resistance or less of a problem with heat dissipation? Or just less of a heavy battery to drag around? (You get the work done to accelerate back when you brake so it's rolling resistance which is the issue rather than mass.)

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 7:18 pm
by bjn
This is a silly conversation, I’m not invested in the idea of solar powered cars. I made a passing observations that 25km/day would do me fine for most of the year.

The infrastructure argument is the same that works against H2 for ground transportation, among many others.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 7:21 pm
by jimbob
Roof solar panels make some sense to me in providing a trickle charge to keep auxiliary electrics charged and possibly fans/aircon for keeping the car less uncomfortably hot if parked in the sun in hot weather.

But as you say, little use in most time

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 8:10 pm
by sTeamTraen
jimbob wrote:
Sun Jan 09, 2022 7:21 pm
Roof solar panels make some sense to me in providing a trickle charge to keep auxiliary electrics charged and possibly fans/aircon for keeping the car less uncomfortably hot if parked in the sun in hot weather.
Thirty or so years ago, Mazda sold exactly that as an option on the 929, so you could leave the car parked in the sun and come back to find it nice and cool. I don't think there was any extra battery involved; the solar power just ran the A/C compressor directly.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 8:25 pm
by jimbob
sTeamTraen wrote:
Sun Jan 09, 2022 8:10 pm
jimbob wrote:
Sun Jan 09, 2022 7:21 pm
Roof solar panels make some sense to me in providing a trickle charge to keep auxiliary electrics charged and possibly fans/aircon for keeping the car less uncomfortably hot if parked in the sun in hot weather.
Thirty or so years ago, Mazda sold exactly that as an option on the 929, so you could leave the car parked in the sun and come back to find it nice and cool. I don't think there was any extra battery involved; the solar power just ran the A/C compressor directly.
Exactly - something that over a day, or maybe weekend parking would be quite a drain on the battery in an ICE or EV range

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 8:38 pm
by lpm
bjn wrote:
Sun Jan 09, 2022 7:18 pm
This is a silly conversation, I’m not invested in the idea of solar powered cars. I made a passing observations that 25km/day would do me fine for most of the year.
Nobody said you were.

But obviously some people are invested in the idea. Literally. And they're surely wrong.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 8:42 pm
by dyqik
jimbob wrote:
Sun Jan 09, 2022 8:25 pm
sTeamTraen wrote:
Sun Jan 09, 2022 8:10 pm
jimbob wrote:
Sun Jan 09, 2022 7:21 pm
Roof solar panels make some sense to me in providing a trickle charge to keep auxiliary electrics charged and possibly fans/aircon for keeping the car less uncomfortably hot if parked in the sun in hot weather.
Thirty or so years ago, Mazda sold exactly that as an option on the 929, so you could leave the car parked in the sun and come back to find it nice and cool. I don't think there was any extra battery involved; the solar power just ran the A/C compressor directly.
Exactly - something that over a day, or maybe weekend parking would be quite a drain on the battery in an ICE or EV range
Here it could also help provide preheating to the battery in winter (our coldest days are usually sunny) or precooling in summer.

It's cold enough here that people install remote starters to cars so that they can let the ICE warm the car up for 20 minutes before they leave the house.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 8:52 pm
by jimbob
dyqik wrote:
Sun Jan 09, 2022 8:42 pm
jimbob wrote:
Sun Jan 09, 2022 8:25 pm
sTeamTraen wrote:
Sun Jan 09, 2022 8:10 pm


Thirty or so years ago, Mazda sold exactly that as an option on the 929, so you could leave the car parked in the sun and come back to find it nice and cool. I don't think there was any extra battery involved; the solar power just ran the A/C compressor directly.
Exactly - something that over a day, or maybe weekend parking would be quite a drain on the battery in an ICE or EV range
Here it could also help provide preheating to the battery in winter (our coldest days are usually sunny) or precooling in summer.

It's cold enough here that people install remote starters to cars so that they can let the ICE warm the car up for 20 minutes before they leave the house.
Yes, but I suspect that the sun mightn't have enough power to do much for that - especially in dark mornings

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 8:57 pm
by dyqik
jimbob wrote:
Sun Jan 09, 2022 8:52 pm
dyqik wrote:
Sun Jan 09, 2022 8:42 pm
jimbob wrote:
Sun Jan 09, 2022 8:25 pm


Exactly - something that over a day, or maybe weekend parking would be quite a drain on the battery in an ICE or EV range
Here it could also help provide preheating to the battery in winter (our coldest days are usually sunny) or precooling in summer.

It's cold enough here that people install remote starters to cars so that they can let the ICE warm the car up for 20 minutes before they leave the house.
Yes, but I suspect that the sun mightn't have enough power to do much for that - especially in dark mornings
Not in dark mornings, but we get more sunshine in winter here than most of England gets in the summer. And the latest sunrise is 7:12 or so, so there's some opportunity.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 9:33 pm
by Bird on a Fire
dyqik lives in Philadelphia.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 9:33 pm
by Bird on a Fire
Not the cheese.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 10:01 pm
by dyqik
Bird on a Fire wrote:
Sun Jan 09, 2022 9:33 pm
Not the cheese.
I've only been to Philadelphia airport once. I had a cheesesteak (sandwich).

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 10:06 pm
by lpm
dyqik wrote:
Sun Jan 09, 2022 8:42 pm
Here it could also help provide preheating to the battery in winter (our coldest days are usually sunny) or precooling in summer.

It's cold enough here that people install remote starters to cars so that they can let the ICE warm the car up for 20 minutes before they leave the house.
Why not just do that from the mains or battery? EVs already do that.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 10:15 pm
by dyqik
lpm wrote:
Sun Jan 09, 2022 10:06 pm
dyqik wrote:
Sun Jan 09, 2022 8:42 pm
Here it could also help provide preheating to the battery in winter (our coldest days are usually sunny) or precooling in summer.

It's cold enough here that people install remote starters to cars so that they can let the ICE warm the car up for 20 minutes before they leave the house.
Why not just do that from the mains or battery? EVs already do that.
You can only use the mains if it's plugged in. And from the battery drains the battery.

For an ICE car, people want to warm both the cabin and the engine and transmission (auto, obvs). You can only warm the cabin, engine and transmission electrically if you install cabin, block and transmission heaters. Not that that's really necessary in New England.

None of this means it's a good idea on it's own, but there are some uses that could make sense.

Re: The Age of Electric Vehicles

Posted: Sun Jan 09, 2022 10:24 pm
by lpm
There's no problem with plugged in. Or on a charging pad thing.

But the key point is it doesn't matter if it drains the battery. They're meant to drain and recharge.

Re: The Age of Electric Vehicles

Posted: Mon Jan 10, 2022 1:17 am
by Millennie Al
lpm wrote:
Sun Jan 09, 2022 10:24 pm
There's no problem with plugged in. Or on a charging pad thing.
That requies proximity to charging facilities. For places like England, that's probably easy to arrange, but many countries have far less densely populated areas with correspondingly less densely situated charging points. Though, of course, that also means that the small amount of energy obtained from the car's panels will not likely get you a useful distance.

[quute]
But the key point is it doesn't matter if it drains the battery. They're meant to drain and recharge.
[/quote]

Draining the battery is usually used to refer to a level of discharge beyond which is recoverable without external assistance. For an EV that would be the point where the range is no longer enough to reach the nearest charging facility. Or for ICE vehicles to the point where the battery is no longer enough to start the engine.

Re: The Age of Electric Vehicles

Posted: Mon Jan 10, 2022 10:51 am
by IvanV
lpm wrote:
Sun Jan 09, 2022 6:12 pm
It has to travel at 70 mph in rain and hail, deal with bird droppings and falling twigs, and will get salty spray this time of year.
Presumably it has some sizable batteries. Because I don't think roof panels are likely to produce anywhere near enough power to drive the vehicle in normal traffic in real time, even in conditions of perfect insolation.

We can charge the batteries on a typical EV from a domestic 7kW charger in about 12 hours, some longer-range ones take longer. But that doesn't provide 12 hours of driving. We are usually talking about range of around 250-350km on that - some of them go up to 500km range, but that would be long charging. So even that 7kW isn't enough power actually drive the vehicle in normal traffic.

I presume this is a small campervan, because a big one will be heavy and need a lot more power than a normal EV. So maybe you can squeeze about 5sq m of panels on the roof. Top quality panels, in perfect conditions you'll get up to 5kW from that, but most of the time rather less. Even in southern Spain the average capacity factor of solar panels is like 25-30%. Britain it's around 11%. And that's for ones that are suitably angled and directed. So we are talking about a number of days to charge what you'd get overnight on a domestic charger. It doesn't matter whether you are moving or not when you charge, though presumably if you are parked up you can try and arrange the panels for best charging. So slow driving, in the sense of a lot of time laid up to recharge the batteries. Which is perhaps fair enough if you are spending a lot of time not moving very far. But it will make the journey from the Netherlands to Southern Spain, if that is where you are headed, take quite a lot of days.

Re: The Age of Electric Vehicles

Posted: Mon Jan 10, 2022 12:05 pm
by lpm
I think people in general have very little idea how much energy it takes to shift 1.5 tons of car around. And very little idea on the amount of energy stored in a litre of petrol.

EVs battery packs are huge, for half the amount of energy in a tank of petrol.

This combines to make the general public pretty confused about what an EV needs and how to handle recharging.

Re: The Age of Electric Vehicles

Posted: Mon Jan 10, 2022 1:07 pm
by Grumble
lpm wrote:
Mon Jan 10, 2022 12:05 pm
I think people in general have very little idea how much energy it takes to shift 1.5 tons of car around. And very little idea on the amount of energy stored in a litre of petrol.

EVs battery packs are huge, for half the amount of energy in a tank of petrol.

This combines to make the general public pretty confused about what an EV needs and how to handle recharging.
If an EV battery contained half the amount of energy in a tank of petrol it would be able to go 800 miles.

Re: The Age of Electric Vehicles

Posted: Mon Jan 10, 2022 1:15 pm
by shpalman
Grumble wrote:
Mon Jan 10, 2022 1:07 pm
lpm wrote:
Mon Jan 10, 2022 12:05 pm
I think people in general have very little idea how much energy it takes to shift 1.5 tons of car around. And very little idea on the amount of energy stored in a litre of petrol.

EVs battery packs are huge, for half the amount of energy in a tank of petrol.

This combines to make the general public pretty confused about what an EV needs and how to handle recharging.
If an EV battery contained half the amount of energy in a tank of petrol it would be able to go 800 miles.
But it doesn't so they can't.