Electric cars

zeupater

AdrianC wrote: »

The whole point of glass sunroofs is that they're transparent, isn't it?

And, yes, transparent PV is out there - but it's very much in its infancy.

Hi

But that doesn't exclude vehicle manufacturers offering two options, unless you know different! .... given the choice between seeing the sky & being a little more energy efficient would probably work well for many who are interested in EVs & if there's little difference in cost, what's the problem with manufacturers repurposing a hole that they've already designed, tested and invested in tooling for? ... think of it as having the potential to provide the equivalent of a gallon or two of free petrol a week in the summer in some countries, yes, possibly even the UK on rare occasions!

HTH
Z

AdrianC

You mean as they do now? Pano glass roofs... or solid. The pano roof option tends to increase CO2 emissions, because of the extra weight.

Oh, and a lot of insurers exclude them from glass cover, because of the cost of replacing them.

zeupater

AdrianC wrote: »

You mean as they do now? Pano glass roofs... or solid. The pano roof option tends to increase CO2 emissions, because of the extra weight.

Oh, and a lot of insurers exclude them from glass cover, because of the cost of replacing them.

Hi

...yet you tend to see plenty of panoramic/moon roof vehicles around (we'll be in one later this evening!), so they're obviously being made ... so your point is ?????

HTH
Z

Martyn1981

AnotherJoe wrote: »

I used never and ten years in the same sentence because there are two different considerations.
Is it economically worth it. No, but now, maybe in ten years time the electric savinsg might work in some climates.
And never because the range will always be limited by physics. There's only so much solar falling on a car and there's only so much of that can be captured and that can oniy manage a certain distance because electric motor efficiency is so close to maximum anyway,
So maybe one day when the cost of adding ten miles a day - at best in the most optimum circumstances - is trivial, let's say spray on solar, or paste on flexible panels, or some such, then it might happen.
And even then for most people in most circumstances it won't remove the need to charge elsewhere, or just not have a car. After all if you need less than ten miles a day use taxis, if you can't always charge in the most optimum circumstances or you don't live in Arizona , you'll need to charge anyway.
So anyone selling PV on cars right now is using it as a trick to make you think you are getting something for nothing. And as my evidence I produce the Lightyear One at one hundred and twenty thousand dollars US. Or the Sonos at more than a Zoe with worse specifications and who's only benefit is you dont need to plug in if you do so little mileage a tenners worth of taxi fares or a £15 charge once a month would cover your driving needs anyway.

You seem to be chasing your tail in a desperate attempt to maintain this argument.

Firstly you argued against a car PV roof, when the discussion was about using large trailer rooves.

Then you suggested a binary choice of car PV v's house PV, but omitted options 1 & 4 - no PV on both, and PV on both.

You've maintained this 'choice' when in reality the two options are not cross-shopped, and not linked to each other (at all). And the coincidence/co-ordination of both happening at the same time is unlikely.

Then we have the irrelevance of one decision being more economical than another decision - in reality if both are economic, then you would consider doing both, you don't choose the best and stop there, otherwise we would all insulate our lofts and refuse to buy LED's.

Now you have moved onto the economics of a PV roof, without knowing the economics of a PV roof - for instance 50p a day saving does sound small, I admit that, but I'm largely immune to such spin doctor trickery in the presentation of numbers, since £1,825 over 10yrs sounds big.

The considerations are actually enormous and we could tie ourselves up in knots discussing them, for instance, a PV roof might allow for say 2kWh's of charging over a long journey. So we could reduce the size of the batt by 2kWh, and (in Adrian pricing) save £1,400, which would be nice. Or it's dark and add no miles to the journey.

Why not simply agree that PV on a leccy vehicle is an excellent idea, and if it's economical, then it's most likely to succeed.

Please don't waste your time doing an Adrian and trying to find problems with solutions, rather than solutions for problems. The real world will always kick your butt, as what will happen will happen regardless of whether you think it's a good or bad idea.

PS Happy Xmas.

AdrianC

zeupater wrote: »

...yet you tend to see plenty of panoramic/moon roof vehicles around (we'll be in one later this evening!), so they're obviously being made ... so your point is ?????

That buyers put up with the downsides - weight, cost - because of the upside - the light in the interior.

zeupater

AdrianC wrote: »

That buyers put up with the downsides - weight, cost - because of the upside - the light in the interior.

Hi

So your point is that buyers wouldn't see the upside of an increase in efficiency, despite many currently looking at EVs doing so on environmental & efficiency grounds? .... odd really, I would have thought that with your posting history and proclaimed support for the rollout of EVs, you'd be amongst the first to welcome anything that improved range between charging!

HTH
Z

AdrianC

zeupater wrote: »

So your point is that buyers wouldn't see the upside of an increase in efficiency, despite many currently looking at EVs doing so on environmental & efficiency grounds?

If you're looking at something as tangible as cost-benefit, then it's easy to see whether it makes sense as a viable investment. Given that pano roof options are rarely much <£500, higher on premium brands, it's not hard to see a solar roof with any kind of viable output being substantially north of a grand, possibly £2k - certainly initially. That's a lot of juice.
(Oh - and it's £1,500 for the solar roof on the plug-in Prius, with the otherwise-standard-fit HUD, blind-spot monitor and rear cross traffic alert removed - and it doesn't even charge the main traction battery. When parked and not charging, it charges a secondary solar battery, which then indirectly charges the main traction battery - which begs the question why all that complexity...? When being driven, it charges the normal 12v battery - which Toyota reckon gives "2-3% increase in hybrid system efficiency" - "depending on weather, up to 3 miles/day" - page 8 of https://media.toyota.co.uk/wp-content/files_mf/1541584331180212MPriusPluginfullrelease.pdf - 180w max output - https://newatlas.com/panasonic-solar-car-roof-prius/48273/ - and it isn't available in the US because it won't pass rollover impact tests.)

That's very different to an intangible benefit such as a light and airy interior.

And let's not forget... <points back to last page>

AdrianC wrote: »

The Prius did start off with a solar panel to feed the climate, yes (nothing new there - Audi were doing similar a decade or more ago), but they have gone for solar-into-traction more recently.

https://electrek.co/2016/06/20/toyota-prius-plug-prime-solar-panel/

Toyota themselves say it "increases efficiency" by 10%... whatever they mean by that. 10% range? On a plug-in hybrid with 22 mile range, 8.8kWh battery (so at 15p/kWh, about £1.30ish)

I think the most likely verdict on it can be summed up simply - if it was any good, it'd be on all EVs. But even St Elon says "Nah - gimmick".

zeupater

AdrianC wrote: »

If you're looking at something as tangible as cost-benefit, then it's easy to see whether it makes sense as a viable investment. Given that pano roof options are rarely much <£500, higher on premium brands, it's not hard to see a solar roof with any kind of viable output being substantially north of a grand, possibly £2k - certainly initially. That's a lot of juice.
(Oh - and it's £1,500 for the solar roof on the plug-in Prius, with the otherwise-standard-fit HUD, blind-spot monitor and rear cross traffic alert removed - and it doesn't even charge the main traction battery. When parked and not charging, it charges a secondary solar battery, which then indirectly charges the main traction battery - which begs the question why all that complexity...? When being driven, it charges the normal 12v battery - which Toyota reckon gives "2-3% increase in hybrid system efficiency" - "depending on weather, up to 3 miles/day" - page 8 of https://media.toyota.co.uk/wp-content/files_mf/1541584331180212MPriusPluginfullrelease.pdf - 180w max output - https://newatlas.com/panasonic-solar-car-roof-prius/48273/ - and it isn't available in the US because it won't pass rollover impact tests.)

That's very different to an intangible benefit such as a light and airy interior.

And let's not forget... <points back to last page>

Hi

Your point being ?? .... frustration, desparation or something more professionally orientated?

EVs are on their way to a house near you too ... arguing otherwise or sticking your head in the sand isn't making any difference. No matter how much effort you expend in an attempt to command the tide change will happen & eventually you'll come to accept it .. well either that or eventually convert an old heap to run on LPG or cooking oil ...

HTH
Z

Herzlos

So how much would a panel save?

Assuming a 1m2 panel at 20% is 200w. EVs will do about 5m/kWh, so that means 1m/200Wh.
Neatly, that means for every hour the roof spends in sunlight, you'll get 1 mile range.
So for a lot of people south of, say, Birmingham, they could get a 4/5 miles a day for free, depending on where the car is (assuming it spends a lot of the day in shadow).

For a lot of people, like some of my family members, they wouldn't even need to plug it in at all over summer unless going on a day out.

That's pretty nifty.

AdrianC

Herzlos wrote: »

So how much would a panel save?

Assuming a 1m2 panel at 20% is 200w.

<points up a bit>

Toyota, the only manufacturer with one in production at the moment, quote "2-3% increase in hybrid system efficiency" in the PDF I linked above. Their roof (made by Panasonic) is 180w.

They don't, afaict, quote any difference in official economy, emission or range figures with and without the roof.