Thunderf00t has lost last of his marbles and remaining bits of credibility

[PlainName]

Is there a sweet spot for roof-top panel size for these?

[wraper]

So my suggestion is that up to now roof-top solar has been seen as a very local (that is, household) thing and whether you have it or not is a personal and financial decision. And it has to be panels, which are a bit ugly and have installation issues. 'Proper' power comes from solar farms. But this shows that housing developments can be a provider in themselves, and as new builds putting solar roof tiles on would be practical where retrofitting to an existing build would not.

In the NL it is not out of the ordinary to use roofing systems with integrated solar panels where the solar panels make the roof water tight as well. Where the small solar tiles fail is that the panels are too small and need too many connections making them too expensive. But the basic idea of using solar panels to make the roof watertight is valid.

Yeah, I think it would make more sense to produce large panels which imitate multiple normal size shingles, accompanied with normal size dummy shingles to fill the extra space.

[tszaboo]

So my suggestion is that up to now roof-top solar has been seen as a very local (that is, household) thing and whether you have it or not is a personal and financial decision. And it has to be panels, which are a bit ugly and have installation issues. 'Proper' power comes from solar farms. But this shows that housing developments can be a provider in themselves, and as new builds putting solar roof tiles on would be practical where retrofitting to an existing build would not.

In the NL it is not out of the ordinary to use roofing systems with integrated solar panels where the solar panels make the roof water tight as well. Where the small solar tiles fail is that the panels are too small and need too many connections making them too expensive. But the basic idea of using solar panels to make the roof watertight is valid.

I've seen these on newer built houses. Seems like a good idea, with some drawbacks. For example panel sizes changing, you cannot just replace it in 10 years when higher efficiency modules make it worthwhile. But there is always upsides and downsides for everything.
I wonder how are these priced, because panels seem to be cheaper than the actual roof shingles nowadays.
Some info:
https://www.greenmatch.co.uk/solar-energy/solar-panels/integrated

I think the efficiency is misunderstood on this page. I think it's supposed to be 5-10% reduction of power, and not 5%-10% loss of efficiency, and the numbers used in their ROI calculation also closer to this.

[EEVblog]

That's what I meant by failure, the vision of solar roof tiles on every roof is a complete demonstrable failure.

Maybe. There is a housing development being built here which will include roof-top panels (one assumes - if it were tiles I'm sure it would be shouted about):
https://www.housingtoday.co.uk/news/council-agrees-deal-for-green-smart-grid-at-8500-home-new-town/5137478.article
The roof-top stuff will provide ~50% of requirements, but the important aspect is:

Australia has almost 50% of homes with solar panels, we are the world leaders in uptake.
That's got nothing to with solar tiles vs solar panels though.
You also have to be careful what you wish for, we have such an abundance of solar uptake that it's now actually a problem, we can't use it all.

[Psi]

...we have such an abundance of solar uptake that it's now actually a problem, we can't use it all.

Pretty easy to fix with a massive uptake in home battery storage. Hopefully that doesnt create a massive increase in house fires.

[coppercone2]

Australia may be the first country to successfully implement a 'great leap forward' in the CCP style with excess solar power to smelt electric iron. One of the things that prevented this from working before was a lack of fuel and energy resources within the CCP. Australia has a large amount of minerals. Iron will eventually come in handy, even if it needs to be further purified.

Induction coils and solar panel might be the missing link. Smaller smelters that don't require too high of a power density, to over come transmission losses as much as possible.

It might be easier then developing that many batteries to use the power to make a metal resource using simple induction heaters.

[AVGresponding]

...we have such an abundance of solar uptake that it's now actually a problem, we can't use it all.

Pretty easy to fix with a massive uptake in home battery storage. Hopefully that doesnt create a massive increase in house fires.

Given the (relative) abundance of space there, one would assume such batteries could fairly easily be located outside the main residence

[tszaboo]

That's what I meant by failure, the vision of solar roof tiles on every roof is a complete demonstrable failure.

Maybe. There is a housing development being built here which will include roof-top panels (one assumes - if it were tiles I'm sure it would be shouted about):
https://www.housingtoday.co.uk/news/council-agrees-deal-for-green-smart-grid-at-8500-home-new-town/5137478.article
The roof-top stuff will provide ~50% of requirements, but the important aspect is:

Australia has almost 50% of homes with solar panels, we are the world leaders in uptake.
That's got nothing to with solar tiles vs solar panels though.
You also have to be careful what you wish for, we have such an abundance of solar uptake that it's now actually a problem, we can't use it all.

Looks like in watt/person, Netherlands and Australia is head to head for the first place, depending on who released the latest data. You are winning with the Wh/person because of the weather here.
The number of hours with negative energy prices here was something like 500 hours on the day-ahead market. Having it on the day-ahead market is insane, it means that they already know that production would be higher than consumption. I can guarantee though that we'll never get a electricity contract with free hours. It's just inconceivable for them to do something nice to the people.

[Simmed]

https://en.wikipedia.org/wiki/Solar_power_in_Australia

i didnt know they make that much
46++ TWh a year

Germany is >55TWh i think ?


meanwhile
crew 10 has returned !

[Psi]

...we have such an abundance of solar uptake that it's now actually a problem, we can't use it all.

Pretty easy to fix with a massive uptake in home battery storage. Hopefully that doesnt create a massive increase in house fires.

Given the (relative) abundance of space there, one would assume such batteries could fairly easily be located outside the main residence

Can't do that. It's too hot outside 

[John B]

Where the solar panel density is highest, in cities, land is also a premium. Some of these new build houses have land sizes 250-300m^2. You can barely open the back doors without hitting your fence. I'm not too keen on a future where your giant flammable chemical bomb is strapped to the house 3m away from the neighbours giant flammable chemical bomb.

I made the sacrifice to get some extra land, so when the time comes to look at batteries I'll have a separate external shed for that kind of stuff.

[EEVblog]

Starship tiles:

[Simmed]

it seems many "treasure hunters" go search for these tiles at the beach
and go on YT to talk about it
1 YTber measured it and its 360g (an unbroken full piece)
its like collecting pokemons 

[coppercone2]

That looks like a good way to package a flat screen TV. I don't want to fly in it though.

[tszaboo]

Starship tiles:

Is there an AI summary for this? I watched it 5 minutes but the intonations TF uses raised my blood pressure like 20. He sounds insufferable.
So my take on this: Yes, engineers often choose other solutions than scientists would, and often times they are optimized differently. Because engineers often times choose cost and lead times over performance.
A scientist needs an opamp and they are given enough money, they will spin their own wafer and spend 2 years making their own parts. This is what NASA did basically, look at their design, every part custom made for them.
If an engineer needs an opamp, he will go on digikey and buy one, delivered tomorrow, spends the rest of the money on beer and pizza.

So often times when you see something strange in engineering design, it's not because of incompetence. You might not understand why it was done that way, but that's usually a you problem, not a design problem.

[wraper]

^He calls it stupid without knowing a jack shit in that area and any requirement that lead to such design choices. Actually his Starship launch livestreams revealed he did not even look into what it was supposed to do during the launch.

[Psi]

I think most people agree that the tiles in their current state are a bit to brittle to be a workable solution for the reliability needed.

The next starship to launch on 24th has a section with some metal tiles and some liquid cooled tiles for testing.
We also don't know if the main tiles on this ship are the same as the last ship that got to reentry, or if they are improved.
It does seem that less tiles come off with each mission. Well.. except for the last two, heh, but that is not tile related.

[EEVblog]

Starship tiles:

Is there an AI summary for this? I watched it 5 minutes but the intonations TF uses raised my blood pressure like 20. He sounds insufferable.
So my take on this: Yes, engineers often choose other solutions than scientists would, and often times they are optimized differently. Because engineers often times choose cost and lead times over performance.
A scientist needs an opamp and they are given enough money, they will spin their own wafer and spend 2 years making their own parts. This is what NASA did basically, look at their design, every part custom made for them.
If an engineer needs an opamp, he will go on digikey and buy one, delivered tomorrow, spends the rest of the money on beer and pizza.

So often times when you see something strange in engineering design, it's not because of incompetence. You might not understand why it was done that way, but that's usually a you problem, not a design problem.

The takeaway is that there are two mains problems:
1) The tiles are not waterpoof, he demonstrated how they absorb water which will not evaporate out, and will freeze and expand and crack once in orbit. Not to mention the absorb water weight.
He also demonstrated an easy coating solution to prevent this

2) The tiles are essentially split in half with a solid stainless steel sheet to hold the attachment pin, thus creating stress points. He showed how they have cracked right at those stress points. He suggested that a stainless steel mesh would have solved this. Not to mention the weight of the plate vs mesh.

I think he's right on both points, so his analysis seems decent. But I'm not a mechanical engineer and neither is he, so he kinda waved his hands around the stress issue. Maybe they have done the FEA and it's fine.
The lack of waterproofness seems like a bad oversight. And the chemistry involved here is his fairly unique specialty, he's literally done papers on water absorption and evaporation etc.

[wraper]

^I see several problems with sealing the tiles completely. If they entrap water through some perforation or during production process, they will take forever to dry. Another problem is that they will entrap air, and once in vacuum they will need to release the air somehow to not crack/explode. As of solid pieces of metal, actually they could act like ribs that bear most the mechanical force and ceramic tile more or less loosely sits on them basically on its own. Actually most likely you do not want ceramic and metal bonded together like it would be with a mesh due to vastly different thermal expansion coefficients and insane temperature swings these will experience.

[nctnico]

Maybe they have done the FEA and it's fine. The lack of waterproofness seems like a bad oversight.

More likely it is not a problem at all or something the people at spaceX are not interested in at this stage of development. First figure out if a potential problem is an actual problem before spending time on it. Second guessing a team of people who have succesfully flown rockets & space craft into space and back is kinda... meh.

[Psi]

I'm sure they have a team of smart people with the needed qualifications and/or experience working on the tiles and I'm sure they're well aware that water absorption + freezing = cracking.
So either they have a solution/plan for that which we don't know about yet, or it's not actually an issue for some reason, or they are still working on it.
I refuse to accept any sentiment that they, or SpaceX, are stupid and don't know what they are doing.

So much stuff is happening in parallel. What we see is unlikely the complete plan.
We often see things with obvious issues that they are rolling with for now because those issues don't really matter for the current testing being done.
Best to work on things internally until they are ready to push to prod.

[EEVblog]

Maybe they have done the FEA and it's fine. The lack of waterproofness seems like a bad oversight.

More likely it is not a problem at all or something the people at spaceX are not interested in at this stage of development. First figure out if a potential problem is an actual problem before spending time on it. Second guessing a team of people who have succesfully flown rockets & space craft into space and back is kinda... meh.

Maybe, but the tiles have been a problem, which is why the latest Starship is testing two new different kinds of tiles. They are probably up to double digit different tile technologies that they have tested thus far. IIRC every Startship launch has had at least several different test tiles on it. So they are iterating like crazy on the tiles.

[EEVblog]

I refuse to accept any sentiment that they, or SpaceX, are stupid and don't know what they are doing.

I'm sure the engineers are great, but they don't always drive the bigger decisions. For example, you don't think that Starship point-to-point passenger transport is fundamentally stupid and impractical?

[CatalinaWOW]

I refuse to accept any sentiment that they, or SpaceX, are stupid and don't know what they are doing.

I'm sure the engineers are great, but they don't always drive the bigger decisions. For example, you don't think that Starship point-to-point passenger transport is fundamentally stupid and impractical?

Yes.  But not much worse than the SST, which lasted a long time and still has quite a crowd wishing it was still around.  And companies actively working to market a replacement.

You have to admit that antipodal trips on subsonic jets is tedious and anything that promises a major drop in the hours in an airplane seat is attractive to those who feel that have to make the trip.  Not making the trip is the obvious and practical answer.

[vk6zgo]

Starship tiles:

Is there an AI summary for this? I watched it 5 minutes but the intonations TF uses raised my blood pressure like 20. He sounds insufferable.
So my take on this: Yes, engineers often choose other solutions than scientists would, and often times they are optimized differently. Because engineers often times choose cost and lead times over performance.
A scientist needs an opamp and they are given enough money, they will spin their own wafer and spend 2 years making their own parts. This is what NASA did basically, look at their design, every part custom made for them.
If an engineer needs an opamp, he will go on digikey and buy one, delivered tomorrow, spends the rest of the money on beer and pizza.

So often times when you see something strange in engineering design, it's not because of incompetence. You might not understand why it was done that way, but that's usually a you problem, not a design problem.

Usually, when you see something strange in engineering design, it is when the device that design appears in has dismally failed, & the unfortunate Tech has to find an effective "bodge" as there are third parties who demand that the thing is fixed.