ajdelange

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With today current solar panel technology it would take 5 panels or even less.

....Trinasolar 670W Ultra-high Power with 21.6% High Efficiency
Cost is of course a consideration and it is great that cheaper panels are available but the really important thing here is the stuff I bolded. For each square meter of panel, no matter how big the panel be, you are only going to get 216 watts per square meter out of it in full, direct, cloudless sunshine when the normal to the panel surface is aimed directly at the sun. Converters are pretty darned efficient these days but you are goung to lose some of that energy to the converter too so 200 W /m^2 is probably a good working estimate. A 2 meter by 6 meter active area is thus going to yield about 2400 W (at full sun).




Agreed the solar energy captured in real-time could not keep up with consumption but that is not the most common use case.
Doesn't matter what the most common use case is. The man asked if he could use the solar panels in the toneau to run the A/C while he was out of the car without running down the battery. The answer is "no". Period. Doesn't matter if he runs it for 5 minutes when the vehicle is best pointed or 5 hours when it can't be (unless someone goes out and moves it.) Could energy collected by solar cells in the toneau offset some of that battery drain? Yes. Is the offset enough to be significant? Well that's really up to the person of whom you ask the question. Most practically minded people would say "no" but there are apparently many who would say "yes". Let's sell them systems and hope it boosts the price of the stock.

Most people spend 3 hours in car only on long trips the occur once a month or so. The most common...
I've driven these things for a couple of years now and have a pretty good idea of how to use the A/C and what impact it has on the battery. The most important aspect of it is that it doesn't consume that much energy in cruise per mile so that you needn't force yourself to swelter on a hot day for fear of losing appreciable range. The other is that it is fast. It will cool a car that's been out in the sun down to comfortable temperature in 10 minutes.



I guess you weren't aware that in all the places I referred to NREL and equivalent hours of full sun that I was using data from this site.

I say again that you are free to grasp at any straw that comes by in order to justify this expense to yourself. Just don't expect practically minded people, especially those with some knowledge of solar systems, to agree with you. Each to his own.
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Tim.Luchenko

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Actually I think he understands them better than you do. As I write this I have an overcast but the sky is bright. My system is producing about 4 kW. At this time of day without cloud it would be producing 22. Thus this relatively light overcast has blocked almost 5/6 of the energy available from the sun.

No, they don't have to be angles perfectly to produce energy but they do to produce full energy. Were the panels oriented such that the elevation was perfect but the azimuth off by 45 ° you would lose 30% and it really falls off fast after that. At 53 ° pointing error you lose another 10%. If one is so marginal even under optimum conditions you can ill afford to lose another 40% and this is why prudent men, such as Musk and FullyGrounded think this is foolish from an engineering point of view. But from a marketing point of view the story is quite different. Years ago the megabrewers discovered that the public was willing to pay a premium price for a beer that was cheaper to make because it required less of the things that make beer beer. If people are willing to pay more for less or something for nothing I want to invest in companies that are willing to sell that. Thus I think Tesla's decision to lock in the rights to sell these virtually useless (from the solar perspective only) tonneau and perhaps even sell them a brilliant business decision.
Why would Elon promissed 15 miles gain if he knows it is not enough even to supply phantom draining?
 

ajdelange

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Because the system he is planning to offer will produce the equivalent of 15 miles range (5 - 7 kWh). Whether those 5 - 7 kWh are used to run the radio, the A/C in dog mode, for traction or phantom drain is really irrelevant. It's sort of like when someone brags that he's earned 3% on his Tesla stock this year (would that it was this good) and some spoil sport comes along and says "Yeah but that doesn't even cover inflation." Pointing out that the gain isn't even enough to cover inflation helps put the value of the gain into a more realistic perspective.
 

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Because the system he is planning to offer will produce the equivalent of 15 miles range (5 - 7 kWh). Whether thos 5 - 7 kWh are used to run the radio, the A/C in dog mode, for traction or phantom drain is really irrelevant. It's sort of like if someone brags that he's earled 3% on his Tesla stock this year (would that it was this good) and some spoil sport comes along and says "Yeah but that doesn't even cover inflation."
Nope.
He does not said that " the system will produce the equivalent of 15 miles range (5 - 7 kWh). "
These are YOUR words!
He clearly said:
1622399690424.png
 

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My speculation is:
he knows about phantom drain, and when he said "solar power that generates 15 miles per day" it is additional to phantom drain. Ofcource, if you can use this power as you want, running A/C, or grilling staeks, or Light the Night Up. I think if you do not have any comsumption of power (exept CT does it by itself and you cannot do anything with it) it will gain power for 15-30 AVG miles per say in US.
 

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People said a lot of things Elon wanted to do were impossible. People who bet against him usually look like fools in the end.

I agree, there are a lot of challenges involved in making a solar tonneau actually provide an appreciable increase in daily range, even in optimal weather. Especially since it will have to be a bunch of tiny panels tied together.

The naysayers are using their current vehicles as comparisons. Unfortunately, those comparisons are apples to oranges. The Cybertruck is going to have all new cells, with significantly reduced losses. That by itself is a huge factor I have not seen mentioned.

Cybertruck also seems to be the flagship vehicle for a lot of new tech and electrical upgrades. Upgrades that we know next to nothing about.

A pre-refresh S or X is the worst possible vehicle to compare to Cybertruck. The refreshed versions may be a better choice, but at the moment, a Y or 3 would probably be the best we have available.

The theoretical maximum efficiency for solar panels is somewhere around 40%. (38% iirc). What makes them worth it is the cost of the panels vs the net energy savings they provide to the end user, or in this case, the convenience of not having to charge as often. (Not how they save the planet.)

If you got solar before the price crash, yeah, you probably won’t save enough money to have an ROI. Like it or not, the price is near rock bottom and still plummeting.

For those who are looking at CT as a forever vehicle, the added cost of solar just might make sense. We’ll have to see if the solar tonneau is good enough to provide an ROI within 6 years or less
 

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Nope.
He does not said that " the system will produce the equivalent of 15 miles range (5 - 7 kWh). "
These are YOUR words!
He clearly said:
1622399690424.png


Elon Musk
@elonmusk
Nov 22, 2019
Will be an option to add solar power that generates 15 miles per day, possibly more. Would love this to be self-powered. Adding fold out solar wings would generate 30 to 40 miles per day. Avg miles per day in US is 30.
Exactly right.
Elon did not just say 15 mi/day. He said possibly more than 15 miles.

Elon is a real engineer, Tesla makes & sells home solar panels and his SpaceX company has plenty of experience with the highest efficiency solar panels in the world.

Elon knows what's possible.

The issue is not efficiency. It is cost. This is just like Tesla battery day presentation. There is no need to wait for solid-state battery or other chemistry breakthroughs. The efficiency of current lithium ion is good enough. The issue is cost per KwH. Most of battery day was how Tesla was going to reduce battery cost with current chemistry.

Efficiency of current solar panels (20-22%) is good enough to use on a mass scale now.
It is the cost/Kw that matters most right now.
If retail prices are $0.55/watt I am sure at Tesla volume & scale it would be lower.

Now need to wait for some future perfect solution.
 
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ajdelange

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Nope.
He does not said that " the system will produce the equivalent of 15 miles range (5 - 7 kWh). "
These are YOUR words!
He clearly said:
1622399690424.png
Perhaps you do not understand how BEV work. What would happen with the solar cells is that they convert sun energy into electrical energy which is stored in the BEV battery. That energy is used to drive traction motors. Each mile driven requires a certain amount of battery energy. We don't know exactly what that is for the Cyber truck at this point but most of us think that it is going to be right around 450 Wh per mile. Thus 450 Wh is equivalent to 1 mile. 15 miles is equivalent to 6750 Wh. The solar cells have to generate 6759 Wh to add 15 mi range to the battery. The solar panels do not generate miles. They generate electricity. Elon is sometimes sloppy with his English in his Tweets (or whatever these are). I realize than English is not your first language and thus understand how you might be confused by this.
 

happy intruder

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Perhaps you do not understand how BEV work. What would happen with the solar cells is that they convert sun energy into electrical energy which is stored in the BEV battery. That energy is used to drive traction motors. Each mile driven requires a certain amount of battery energy. We don't know exactly what that is for the Cyber truck at this point but most of us think that it is going to be right around 450 Wh per mile. Thus 450 Wh is equivalent to 1 mile. 15 miles is equivalent to 6750 Wh. The solar cells have to generate 6759 Wh to add 15 mi range to the battery. The solar panels do not generate miles. They generate electricity. Elon is sometimes sloppy with his English in his Tweets (or whatever these are). I realize than English is not your first language and thus understand how you might be confused by this
is the 450Wh per mile a real value or close estimate.....seems a little high.....I figured the avg Wh to be around 375-425.....thoughts?
 

ajdelange

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My speculation is:
he knows about phantom drain, and when he said "solar power that generates 15 miles per day" it is additional to phantom drain. Ofcource, if you can use this power as you want, running A/C, or grilling staeks, or Light the Night Up. I think if you do not have any comsumption of power (exept CT does it by itself and you cannot do anything with it) it will gain power for 15-30 AVG miles per say in US.
The phantom drain is there like it or not. You have some control over it by not installing apps that poll the car for data.

It is true that the adding 7 kW hr from solar will result in 15 more miles range with phantom drain than not adding 7 kWh with phantom drain. The phantom drain is just used as an example of a small load and often cited here to emphasize the small magnitude of the benefit of solar. One could also point out that the Trimotor has 500 mi nominal range and that adding 15 miles is 3%. That's going to get a "meh" from most people and if the option costs a couple of k they are going to turn it down. Especially those who understand that the 15 miles is best case.
 

ajdelange

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People said a lot of things Elon wanted to do were impossible. People who bet against him usually look like fools in the end.
A lot of the things he wants to do are impossible. Colonize Mars? He's mad. But brilliant. Nicola Tesla, after whom he named his company, was also mad but brilliant. How long ago did Elon start saying that we'd have Robotaxis by the end of the year? But he's still one of the people I most admire.

This is of course totally irrelevant to the discussion at hand. No one doubts that Tesla can put a solar array on the toneau and there really isn't that much debate as to whether the output is going to be 3 kWh/da or 7. The question is as to whether that's worth anything. In terms of performance of the CT it's not very impressive. In terms of "and my car charges it's own battery from the sun" brags it is and as a marketing ploy it's brilliant. I'm betting with the boy on this one. The stock needs a boost.

I agree, there are a lot of challenges involved in making a solar tonneau actually provide an appreciable increase in daily range, even in optimal weather. Especially since it will have to be a bunch of tiny panels tied together.
The technical challenges have been solved. The problems are that one can only cover so much area with cells, that the cells are subject to the Shockley limit, that the sun only produces so much power when it shines from the right direction and that it doesn't shine all day nor every day nor from the right direction for much of the time it does shine. All these lead to a kind of "meh" reaction.

The naysayers are using their current vehicles as comparisons. Unfortunately, those comparisons are apples to oranges. The Cybertruck is going to have all new cells, with significantly reduced losses. That by itself is a huge factor I have not seen mentioned.
The type of vehicle has absolutely nothing to do with it. If you tell me you have an option that will add 3% range to my vehicle under optimum conditions and less than half that under realistic conditions I'm not going to get too excited unless the cool factor is pretty great. Solar on the car has a big cool factor. So I'll fork over for it. There are, after all, no pockets in the shroud. I'm a nay sayer because I know it to be silly. You guys think it's the neatest thing since silicon carbide transistors.

A pre-refresh S or X is the worst possible vehicle to compare to Cybertruck. The refreshed versions may be a better choice, but at the moment, a Y or 3 would probably be the best we have available.
As nobody has compared the Cybertruck to any of these vehicles WRT to solar tonneau (none of them have a tonneau at all) no one of them is better than the other.

The theoretical maximum efficiency for solar panels is somewhere around 40%. (38% iirc).
You don't. It's about 33.7%. That's for single junction cells. Higher efficiency is available with multilayer cells but these are still in the labs.

What makes them worth it is the cost of the panels vs the net energy savings they provide to the end user, or in this case, the convenience of not having to charge as often.
They won't save me anything at all nor will they change how often I charge at all. The vehicle will stay plugged in when ever it is in the garage. It will charge when it wants to. They provide no savings as I'd do better to invest the money in more panels on the house.


For those who are looking at CT as a forever vehicle, the added cost of solar just might make sense. We’ll have to see if the solar tonneau is good enough to provide an ROI within 6 years or less
If you are pushing this from an ROI POV I want some of what you are smoking. But keep pushing. If you can bring enough people round they'll buy this option (if in fact it is ever offered and I have my doubts). Then the stockholders will get an ROI on your investment.[/QUOTE][/QUOTE]
 

ajdelange

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is the 450Wh per mile a real value or close estimate.....seems a little high.....I figured the avg Wh to be around 375-425.....thoughts?
Well if it has 500 mi range with 450 Wh/mi consumption it would need a 225 kW hour discharge capacity battery. At 375 the battery would be 187.5 kWh and at 400 it would be 200. Those are all reasonable estimate for battery size IMO so I could live with any number in the 375 - 450 range. I tend to be conservative so I go with the upper limit but I really don't think it's going to have a pack bigger than 225 kWh.

To be clear, I'm not privy to any information you don't have. The 450 is not bases on any special knowledge.
 

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A lot of the things he wants to do are impossible. Colonize Mars? He's mad. But brilliant. Nicola Tesla, after whom he named his company, was also mad but brilliant. How long ago did Elon start saying that we'd have Robotaxis by the end of the year? But he's still one of the people I most admire.

This is of course totally irrelevant to the discussion at hand. No one doubts that Tesla can put a solar array on the toneau and there really isn't that much debate as to whether the output is going to be 3 kWh/da or 7. The question is as to whether that's worth anything. In terms of performance of the CT it's not very impressive. In terms of "and my car charges it's own battery from the sun" brags it is and as a marketing ploy it's brilliant. I'm betting with the boy on this one. The stock needs a boost.

The technical challenges have been solved. The problems are that one can only cover so much area with cells, that the cells are subject to the Shockley limit, that the sun only produces so much power when it shines from the right direction and that it doesn't shine all day nor every day nor from the right direction for much of the time it does shine. All these lead to a kind of "meh" reaction.

The type of vehicle has absolutely nothing to do with it. If you tell me you have an option that will add 3% range to my vehicle under optimum conditions and less than half that under realistic conditions I'm not going to get too excited unless the cool factor is pretty great. Solar on the car has a big cool factor. So I'll fork over for it. There are, after all, no pockets in the shroud. I'm a nay sayer because I know it to be silly. You guys think it's the neatest thing since silicon carbide transistors.

As nobody has compared the Cybertruck to any of these vehicles WRT to solar tonneau (none of them have a tonneau at all) no one of them is better than the other.

You don't. It's about 33.7%. That's for single junction cells. Higher efficiency is available with multilayer cells but these are still in the labs.

They won't save me anything at all nor will they change how often I charge at all. The vehicle will stay plugged in when ever it is in the garage. It will charge when it wants to. They provide no savings as I'd do better to invest the money in more panels on the house.


If you are pushing this from an ROI POV I want some of what you are smoking. But keep pushing. If you can bring enough people round they'll buy this option (if in fact it is ever offered and I have my doubts). Then the stockholders will get an ROI on your investment.
[/QUOTE]
[/QUOTE]

There are plenty of people who have paid for their home solar with the energy cost savings that they have netted. Most of these folks are in states with high energy costs. However, those with solar roof installs are reporting impressive cost savings even in low-cost states. The data is out there. You sound bitter. Did you buy your solar too early?

Personally, I dislike solar and wind. Hate it on a utility scale. I want nuclear power, everywhere, and no utility-scale “renewables” at all. I’m looking at solar roof for a new construction home, because when I crunch the numbers, it saves me money. Better than an asphalt roof and just as long lasting as a metal roof. Sure, the solar may eventually die completely, but I’ll still have a solid roof for about the same price as a metal roof.

I’m hoping that the solar tonneau is not an option at all, but standard on all CTs. I’m thinking its going to be structurally integrated into the tonneau, and there won’t be much difference in cost in a tonneau with solar vs one without. The cost of having two separate tonneau designs and two separate installation procedures may exceed the profit they would realize by selling it as an option. Though, they could go the route, as others have suggested, of a software lock. I hope they don’t.
 

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Perhaps you do not understand how BEV work. What would happen with the solar cells is that they convert sun energy into electrical energy which is stored in the BEV battery. That energy is used to drive traction motors. Each mile driven requires a certain amount of battery energy. We don't know exactly what that is for the Cyber truck at this point but most of us think that it is going to be right around 450 Wh per mile. Thus 450 Wh is equivalent to 1 mile. 15 miles is equivalent to 6750 Wh. The solar cells have to generate 6759 Wh to add 15 mi range to the battery. The solar panels do not generate miles. They generate electricity. Elon is sometimes sloppy with his English in his Tweets (or whatever these are). I realize than English is not your first language and thus understand how you might be confused by this.
You talk like you are the only person here with real work experience and only you know what makes economic sense.
Well you are NOT the only one.

Despite being in Mexico. I am a trained EE too & have several friends who are EEs too who work at electronic/electrical component suppliers to US/Mexico automotive industry.
I probably know more about BEVs operate than you do.
I have installed solar panel systems.
I have hands on in work in metal fabrication of heavy equipment (steel, cast iron, aluminum).

You are the one that makes claims about Cybertruck consuming huge levels of KwH without any real data to back it up.

Elon said nothing about how many KwH the solar on Cybertruck would create.
Elon said 15 miles or more a day.
Maybe the Cybertruck only uses 300 Kwh/mi.
Whatever Elon has in mind with the solar option it is much more than just for phantom drain.

And another one of your expert perceptions is wrong.
There is nothing in my writing to indicate I am not a native speaker. In fact I am a native English speaker and grew up in U.S. I did not learn Spanish until I went to college. For over 20 years I have also taught English. When I worked in the U.S. corporate world we all had to go to seminars on how to be more effective communicators when working in teams. Some training was similar to the skills airline pilots & copilots use to reduce miscommunication. Even when I am in the U.S., my English is well above average and so is my knowledge of history, science, economics, business.
 
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