Electric cars

zeupater

AdrianC wrote: »

<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.

Hi

... and many would read that as being an overall increase in efficiency which would directly translate to an increase in range if the conditions allow ....

Having taken the effort to locate a source from which to mount an argument, I'm quite surprised that you missed the following ....

Solar panel roof, enabling around 400 miles of all-electric driving a year in UK city traffic

... which would work out at around 5% for a motorist averaging 7.5k miles/year in built up areas in the not so sunny UK! ...

Read it as you will, but it's your PDF source as raised to maintain your ongoing 'not anti-EV' argument and that's with a mere 180Wp panel - just think what a roof with a 300-500Wp panel set-up could achieve in more suitable locations! :cool:

HTH
Z

Herzlos

AdrianC wrote: »

<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.

And that hybrid does 5m/kWh? Whilst I'm talking about the potential of EVs and roofs, your attempt to refute it proves my point. 2-3% increase in a hybrid is one thing, what makes you think a pure EV would be worse?

That there's only 1 manufacturer doing it now is irrelevant. If it becomes more viable in future we'll see more of it.

Martyn1981

Herzlos wrote: »

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.

Again your numbers look sound. For the UK around 170kWh pa (at 85% gen v's pitched). So perhaps 700-850 miles. Sunny summers day around 1.4kWh or 7 miles.

And all joking aside, regarding Birmingham, location doesn't matter as much as some might think, with only a 20% difference in the UK from top to bottom. In fact it's hard to find anywhere that generates more than twice as much as the UK, Spain is about +50%, Australia +60-80% etc.

So, as always it comes down to the economics.

It was noticeable that AnotherJoe in trying to discredit the three cars I mentioned, omitted the aCar. Perhaps because it's a really cheap EV, with a really cheap PV roof solution, which will be really useful in off-grid use (from little acorns ..... etc etc.) certainly harder to knock.

So we have the issue being addressed from all directions - the usual top down development where expensive vehicles get options that eventually find their way to cheaper vehicles. We have the very cheap 'bolt on some panels' solution from the bottom up. And we also have some middle market, dare I say environmentally targeted options where the economics are not the only consideration.

Perhaps we will also see solar glass options, which are less efficient (~6%) and do cause shading as the efficiency rises, but since cars need both glass and shading, that seems like a good combination too.

Herzlos

I thought the north/south difference was a lot greater than that, but then it must have been nearly a decade ago someone ran the numbers for a PV array up in Glasgow and it wasn't viable. There are a lot of them popping up now so the efficiency has likely changed that.

Martyn1981

Herzlos wrote: »

I thought the north/south difference was a lot greater than that, but then it must have been nearly a decade ago someone ran the numbers for a PV array up in Glasgow and it wasn't viable. There are a lot of them popping up now so the efficiency has likely changed that.

Have a play with PVGIS, it's an excellent tool.

Leave everything alone, and just pop random pins over the UK, and the calculate button will give you an annual total, which with the default on 1kWp, should give you figures ranging from high 700's to low 1,000's, typically (ish) 1,000kWh/kWp near the south/west coast and 800(ish) in Scotland.

Then you get anomalies such as Edinburgh and Aberdeen at about 900, and Dundee 950+, which probably reflect cooling from the sea winds. Glasgow shows up at about 850.

For me in Cardiff it's close to 1,000, but as I have an E/W roof I get about 800, but can install twice the PV as a single south facing roof.

So lot's to take into account, but the big one most folk miss/ignore/ignorant too is the effect of temp on panel performance. They like to be cold, so in sunny (hot) countries, performance drops off, whilst cold UK not so bad. Hence the strange result that the 'best' locations only generate about twice what a UK PV install will.

Years ago I said that PV was viable in the UK, but wouldn't catch on-shore wind for £/MWh ...... now it's getting close, and with higher efficiency PV arriving (more gen from the same footprint), will probably become the cheapest generation in the UK ...... bit of surprise that!

AdrianC

Martyn1981 wrote: »

Again your numbers look sound. For the UK around 170kWh pa (at 85% gen v's pitched). So perhaps 700-850 miles. Sunny summers day around 1.4kWh or 7 miles.

<pokes PVGIS>
So taking that Toyota flat 180w panel, and keeping every other variable as default... Yes, it'll produce 170kWh/year of electrickery - down at the very southern tip of the Lizard peninsula, the most southerly point of the mainland. At 15p/kWh, that's a snidge over £25/worth.

Go north to you in Cardiff, and it drops to a bit over £22/worth. Manchester, just over £20-worth (the 20% drop you suggest north-to-south), down to about 32% drop and £17 in Fort William.

Now, perhaps we can go back a step and you can explain why I'm apparently FUDing by asking why it makes any sense at all to tick the box for the £1,500 option on a new Prius plug-in...?

Martyn1981

AdrianC wrote: »

<pokes PVGIS>
Go north to you in Cardiff, and it drops to a bit over £22/worth. Manchester, just over £20-worth (the 20% drop you suggest north-to-south), down to about 32% drop and £17 in Fort William.

Oops, Ade got all the numbers wrong yet again.

It's 20% north / south of UK comparing PVGIS at default settings. Manchester is particularly low around 850-900 (so no surprise you mention that), whilst just to its left is Liverpool at around 900-980, and as mentioned earlier, Dundee at about 970.

Flat pitched we see Dundee at 84% of Penzance. (75% at John o'Groats).

zeupater

AdrianC wrote: »

<pokes PVGIS>
So taking that Toyota flat 180w panel, and keeping every other variable as default... Yes, it'll produce 170kWh/year of electrickery - down at the very southern tip of the Lizard peninsula, the most southerly point of the mainland. At 15p/kWh, that's a snidge over £25/worth.

Go north to you in Cardiff, and it drops to a bit over £22/worth. Manchester, just over £20-worth (the 20% drop you suggest north-to-south), down to about 32% drop and £17 in Fort William.

Now, perhaps we can go back a step and you can explain why I'm apparently FUDing by asking why it makes any sense at all to tick the box for the £1,500 option on a new Prius plug-in...?

Hi

So why are you worried? ... some time ago I mentioned that they weren't financially viable at the moment, but that doesn't mean that will always be the case - particularly considering that the mark-up must currently be huge on the option that you're investing effort in creating argument against!

As already stated, the current cost of rooftop PV panels works out at around 30p/Wp - apart from a little forming the application of technology is almost identical, so apart from maintaining a base for continuing argument against EVs why would you not expect costs of integrated PV in the automotive sector to generally align with that currently available in the commercial/domestic sectors within very accelerated timescales? ... in the real world 180x30p falls well short of your £1500 so as EVs become mainstream it's logical to conclude that PV will also become a mainstream component of standard specifications.


HTH
Z

Martyn1981

AdrianC wrote: »

Now, perhaps we can go back a step and you can explain why I'm apparently FUDing by asking why it makes any sense at all to tick the box for the £1,500 option on a new Prius plug-in...?

Instead, could we go back two steps, and you can show me where I said you were FUD'ing about the plug-in Prius?

Perhaps you could read all my comments, which started with the PV truck trailer roofs, which I think is an excellent idea, and more than likely to be economically viable, especially with cheap printed PV.

Then my comments on car PV, which I've stated is less viable.

Then my comments throughout, where I have always stated 'if economical' but have shown my support for the idea, which I believe will become viable for cars.

I've no idea why your fixation on the P-I-Prius has anything to do with the economical viability of transport mounted PV in the future. It's looks to me, more like you just being you and trying to find some way to twist or spin reality against EV's - just like your pathetic attempt to disagree with EV trucks being quieter than diesels trucks ....... because some have power-take-off devices that also make a lot of noise.

Please state that diesels are quieter than EV's or drop the matter.

Please state that transport based PV is not, and never will be economically viable, or drop the matter.

Herzlos

AdrianC wrote: »

Now, perhaps we can go back a step and you can explain why I'm apparently FUDing by asking why it makes any sense at all to tick the box for the £1,500 option on a new Prius plug-in...?

It doesn't make sense at current prices for a Prius Hybrid. No-one said it did and no-one but you is talking about Prius hybrids.

Costs will go down and efficiency will go up. Would you select it as a £50 option?

It may be a bigger sell from a convenience point of view.