Solar panels disguised as terracotta tiles in Pompeii | Hacker News Reader

Solar panels disguised as terracotta tiles in Pompeii

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359 pointsodewahn139 comments

Here's the product datasheet: https://www.dyaqua.it/invisiblesolar/_en/documents/rooftile-...

An independent research center lists the efficiency as 0.111: https://integratedpv.eurac.edu/en/products/modules/invisible...

Anybody know how that compares to an average panel on the market today? From a quick search it seems like the best you can actually buy is 0.22 efficiency.

Edit: The best available on this site is 0.216 (https://integratedpv.eurac.edu/en/products/modules/fu-425-m-...), but I think they only test Italian-manufactured products. 0.111 is on the low end, but significantly better than a few things like solar glass.

That's fine, they look great. Realizing we've got stuff looking like that that generates freakin' electricity is amazing.

Given the poorer efficiency, wouldn't it be better use of limited money and resources to put regular tiles on houses and normal solar panels somewhere else?

(Honest question. I've always wondered why residential rooftop solar, especially since it's usually government subsidized, makes sense anywhere in the world.)

"I've always wondered why residential rooftop solar, especially since it's usually government subsidized, makes sense anywhere in the world."

Transmission isn't free and the surface is already there.

Both places are fine.

Land tends to be expensive; it would be a real challenge in Europe to find somewhere that isn't being used already for some economic purpose, and also isn't a conservation area and/or physically inacessible or difficult to build on.

Adding to the great points already here, decentralized production makes the system more robust to accidents, terrorism, and war. Not immune by any stretch, but more robust.

It's an historical site. The whole point of these tiles is that they visually fit in with the ruins.

These are not tiles you would use for general solar production.

It's an active volcano, you need to run power lines, the ground shifts, and it can blow any time.

It makes sense to make your own power for yourself and you can sell it back to the grid.

I mean if you own multiple properties, sure...

But if it is your house and you don't want to compromise on look, it's a way.

It makes sense to put nicer looking tiles on rooftops if you value the looks of them. You would then find normal looking tiles a tax. That‘s why it could make sense to put solar panels on roofs that don‘t impose this tax on you even if their efficiency is lower.

This answer is to "given that you want solar panels, why put tiles". I think the question is "given that you want tiles, why put solar panels".

Why not both? SolarCity (now Tesla) had solar panels that looks like roof tiles. There's a lot of roof space in any town, it makes sense to use that instead of use up land (that could be used for housing or agriculture) for solar power generation.

But it can be all of the above, too. More energy produced is not going to go to waste, and there's plenty of unusable areas like deserts where solar electricity can be generated in various ways.

Money is being optimized if the land is not free. Solar panels are relatively inexpensive even if inefficient if the land is sufficiently expensive. Electricity cost can vary a lot. If you have a lot of expensive panels and don't have to hook up to the grid that can save a lot of money

A properly designed house with solar can be energy neutral over the year in the UK (not notable for its sunny climate).

What does energy neutral mean? What does properly designed mean? And at what cost to comfort or the property? You could turn off all your electricity and heat yourself with kerosene and have used no electricity for the year.

Usually means "passivehaus", and "energy neutral" would mean "generates an equal quantity of electricity to that consumed, when summed over the year".

> heat yourself with kerosene

That's not energy neutral, is it now, unless you have a kerosene well on the property.

Precisely - for a smallish 120sqm house the passivhaus heat demand is 1800kWh. 3000kWh is not unreasonable for additional electricity consumption. With a heat pump that heat demand should pessimistically translate into <1000kWh electricity, giving us a total energy usage of ~4000kWh. That's about what a medium size (~20sqm) south-facing roof-mounted PV installation would achieve in the south of the UK.

Geothermal energy would be amazing! But it's hard to balance with carbon emissions.

It's useful for the NIMBYs and historical conservation areas.

I mean, not wanting commercial solar farms in your back yard seems like one of the more reasonable things to not want in your back yard. Especially when aesthetically pleasing (if less efficient) rooftop solar fits the bill nicely.

Yeah, but they are also crazy expensive. From their website is 7k Euros for 1kW of installed capacity (not sure if the price includes then installation). I understand beauty factor, but damn. For Pompei it's perfect though

I have worked in the solar industry. As a reference, the average efficiency of "normal" solar panels is around 16% today.

People, including me were installing panels like crazy last year. They are all 20%+, upto 22-something and did cost me 176€ a piece (that includes VAT).

Does that mean that in high intensity regions you'd need active cooling or is that not a problem?

This doesn't answer your question, but I really wish someone would offer off-the-shelf panels with tubing on the back to hook up water lines. It would be dope to cool my panels and preheat my hot water at the same time.

They are usually called "hybrid solar panels" and not exactly a new thing.

Usually cheaper to just put more panels tho. Pretty handy if you need to get the most out of roof space but otherwise more panels + heat pump water heater is much simpler solution.

There's one combining a heat exchanger and photovoltaics: https://triplesolar.eu/en/introduction/

> The front side of the PVT heat pump panel is similar to a solar panel and has solar cells to generate electricity. The backside is a heat exchanger that supplies the energy source for the heat pump. The heat exchanger-collector collects energy form the ambient temperature and additionally from daylight and sunlight.

Not sure how it does throughout the whole season.

They exist! For example: https://www.todoensolar.com/epages/61987244.mobile/en_GB/?Ob...

"Rad" more than "dope" :)

I've seen a DIY system where the panels are boxed in, and the hot air created behind the panels used for blown air / heat recovery heating.

So for those not in the know, fun fact, solar panels work better when they don't get hot. So things like airflow for passive cooling do matter.

I'm aware of several large-scale solar situated in hot regions with no active cooling, so I guess my answer to your question is no, high effeciency panels in hot environments do not need active cooling.

Roof tiles are a different question. There's no airflow underneath them. So they probably get hot. Hot enough to matter? That's hard to say. Do they have the same thermal properties as a regular tile? What is the impact on building temperature? These would be factors to consider during construction. More insulation, better airflow, and do on.

Incidentally since they are not flat (at least not in the picture) that likely accounts for the lower effeciency).

According to some testing, it matters:

https://youtu.be/Mt9qLRN7JvA

FWIW, the way roofs are designed these days (at least over here in Belgium) there is supposed to be a little bit of airflow underneath your roof, which is achieved by letting the ridge and hip tiles hover over the roof (instead of cementing them like they used to do) and putting a perforated grate at the bottom just above the gutters instead of boarding it up.

Would one be able to extract energy out of the hot tiles as electricity? With a heat exchanger?

Where would you put the cold side?

Fun fact: resistance sucks and makes your electrons bump into protons and crash causing waste heat. Super conductors are usually supercooled and have 0 resistance and every electronic works more efficiently cooler.

> resistance sucks and makes your electrons bump into protons

This is a myth with little bearing to reality. Protons (and the atomic nucleus) are insignificantly tiny when compared to the size of an atom. The major contributor to electrical resistance are defects to the crytal lattice of metals and grain boundaries.

Don't you need the defects to have semi conductors? I seen some really cool experiments with superconductors and every computer works better cold. Isn't that why Google's quantum computer is supercooled?

> Don't you need the defects to have semi conductors?

No. However, most of the time you want doped semiconductors and doing that introduces defects. The defects are bad for resistive losses but that's life.

> every computer works better cold

No. Conventional electronics based on doped semiconductors don't work below a certain temperature because the impurities are "frozen". There is a sweet spot of temperatures that works best. The purpose of cooling on a computer is to keep the temperature as close to the sweet spot as possible.

> Isn't that why Google's quantum computer is supercooled?

Quantum computers like Google's rely on superconducting materials (most of) those require sub-Kelvin temperatures to work, both to reach the superconducting regime and to reduce phonon induced decoherence. Superconductivity works in quite a different way to conventional materials to conductivity in semiconductors and metals too.

The temperature coefficient of resistance is real, though, and could do with an explanation that isn't too quantum.

Of course it is! And the explanation isn't even too quantum. Heat induces atoms to vibrate, these vibrations mess up with the perfectly periodic potential that you would have at 0 K and induces electron scattering which leads to more electrical resistance.

I believe Longi sell a 22.8% module. Individual cells run 26%.

The thought of future archaeologists being thoroughly confused by Roman terracotta tiles that apparently generates electricity amuses me.

Sufficiently advanced civilizations seem likely to integrate energy generation technology to the point of invisibility, optimizing for aesthetics and potentially going classical and opting for something that looks like ancient Rome or Egypt.

It seems unlikely that the pyramids were power plants and obelisks energy receivers [1], but maybe power plants of the future will look like the pyramids and energy receivers like obelisks.

The pyramids seem to have been built in the 26th century BCE rather than 100th, but an advanced ur-civilization may have developed the means and will that "they actually got out with whisk brooms, scoop shovels and little spoons and cleared out every single trace of their daily lives, their utensils, their pottery, their wood, their tools and so on" [2].

1. https://medium.com/understanding-reality/were-the-pyramids-p...

2. https://www.pbs.org/wgbh/nova/pyramid/explore/howold2.html

>but maybe power plants of the future will look like the pyramids and energy receivers like obelisks.

Unless people in the future become religious nuts even worse than today's, I don't see why they'd waste so much space and resources on power-generating burial mounds. The pyramids may be impressive for a primitive civilization to build, but they were functionally completely useless and just a collosal waste of manpower, materials, and space.

This is quite unlike solar-power-collecting terra cotta roof tiles: roofs serve a real purpose, on buildings that people live and work in.

People built 1000s of churches and cathedrals which, at face value, was a collossal waste of manpower, materials, and space.

And yet we admire them and keep them around for 100s or 1000s of years, because of their greatness. The same for the pyramids. Of course, the effort served a function as well: to establish and maintain a power structure, to give people whose lives hung on strings far more often than ours do a sense of safety and hope.

Man needs greatness. A glimpse of the divine. Our civilization has lost this, and the hyperfunctionalism has taken over our cities. We have removed even ornament and other signs of beauty from our buildings. And it has made them worse.

But these trends come in waves. 50 years from now and we might again spend extra money on whatever will be the equivalent of neogothic or classicist buildings.

And I‘m looking forward to it.

Churches did serve a very practical purpose though. They were gathering places and centers of socio-political power. Unlike the pyramids ordinary people could enter churches at any time. And for most churches were the only places were they were exposed to art and “higher” culture (by medieval standards).

From that perspective they are not particularly less practical than modern museums or most other public buildings.

The Egyptian pyramids lacked all of this.

”and the hyper Functionalism has taken over cities. We have removed even ornament and other sign of beauty” if I recall correctly, the late author Paul Fussell called this ’the prolitarization of society’ or something similar. He pointed at that architecture used to symbolize something greater than the individual, not so much anymore

I'm not advocating bulldozing ancient churches or the pyramids, but to build those things (or modern equivalents in terms of resources as a percentage of resources available to the society at large) today would be supremely stupid and wasteful. Arguably, wasting resources on burial mounds might be part of why Ancient Egyptian civilization collapsed, just like the civilization of Rapa Nui (Easter Island) with their statues.

We still build great things, but today they're functional: skyscrapers, for instance. They're not really the most efficient type of building, but they are functional. And modern buildings are not devoid of ornamentation or signs of beauty, we just don't find gargoyles to be fashionable any more.

We’re still will to dedicate large amounts of resources for building museums, concert halls and other public buildings that fundamentally don’t really have a more practical purpose than medieval churches.

What? This is really dumb. Museums are extremely practical, just like schools: they educate people. Concert halls are for entertainment; they're just as useful as restaurants (after all, you could just eat microwave meals at home). Most public buildings have some kind of valid use that doesn't involve superstitious beliefs. Even medieval churches probably had some non-supernatural uses, I'm guessing, like being used as meeting halls or for public addresses. Egyptian pyramids had none of this: a few pharoahs' dead bodies were sealed away inside them along with lots of treasure, and that was it. Everyone else got dumped in a pit when they died.

Edit: I see your point now, that medieval churches had other functions besides the religious stuff. Still, I see those things as only secondary functions to the buildings; museums and concert halls have those things as their primary functions and are optimized for them. I've been in medieval churches, and there's very little artwork in them, relative to their size, compared to any decent art museum. But I agree, they were a lot more functional for the people of the time than the pyramids.

The function of a thing can be solely "wow, this thing is impressive", and that's fine.

Even if medieval churches had no purpose other than to construct an impressive structure, that isn't something we ought to deem unworthy. Greatness is a fine goal in its own right.

After all, art museums and concert halls overwhelmingly display the things that people find impressive. The things that people don't find impressive don't stand the test of time.

Utilitarian function is certainly a great virtue, but it is not the only virtue.

Pyramids were likely symbols of power and unity[1], for the pharaoh of course, but also for the whole Egyptian civilization. This is a very practical purpose.

[1] In fact the burial aspect might even have been a secondary one.

https://www.theguardian.com/artanddesign/2020/jul/11/skyscra...

> keep them around for 100s or 1000s of years

Offtopic, but I love that I read this as "we keep them around for one hundreds to one thousands of years".

>but they were functionally completely useless and just a collosal waste of manpower, materials, and space.

That's how you show affluence. With all the resources we have, we don't have enough to waste them. From that point of view, that civilization was much more than primitive. Also: [1].

1: https://en.wikipedia.org/wiki/Axial_precession#Ancient_Egypt...

Ancient people worshipped and brag about their favored relationships with energy sources (the sun)

Modern people hide their energy givers and their dependency on them (gosh forbid your tv has power cords showing)

>>modern people hide their ... power cords

Except those decorative halogen lights that hang from the + and - wires. As a kid I was messing with a pendant light over my kitchen island and accidentally bridged those wires together!

Terracotta tiles were probably more about practicality than astestics as well. There is a good chance that we only find it astetically pleasing because we associate it with historical architecture. If that had been shiny black surfaces we may have thought that modern solar panels look beautiful and antique.

Don't get me wrong, I think it is great to have more choice in what solar panels look like and I think preserving the appearance of historical architecture is important. But I don't think that one is fundamentally more astetically pleasing than the other. It also makes the idea "integrated to the point of invisibility" an interesting concept. What is invisible? Most of our current building are founded in practically with astestic choices a minor customization on top.

Future archaeologists will probably have access to the HackerNews archive. Archaeology is not as fun in the future as it is today.

Nah, in the event of societal collapse, pretty much all digital information storage will likely be lost forever. Even without societal collapse, a lot of digital information storage is likely lost forever. As near as I can tell, some of the software that I released into the public domain (when open source was still very much a niche thing) in the 80s has vanished completely. I’d kind of like to find my VMS¹ and CMS² software for the TeX ecosystem, if only to revisit my younger self.

⸻

1. I did some nice integration of TeX and friends into the VMS CLI setup so that, e.g., one could access iniTeX by doing TEX/INIT or set a number of parameters via command line prompts.

2. I completed ports of some of the fringe TeX-related apps like MFT and also wrote a DVI previewer which could display a preview of TeX output for people connected to their VM/CMS system via the Kermit terminal software which supported Tektronics graphics. A developer in Germany contributed GDDM support for IBM’s graphics terminals.

You mean in 500 years, nobody's going to dig up the server rack in my house and figure out how to rig the Ceph cluster back up?

That server rack clearly the the Rosetta Stone of the future. It is the key to the understanding of all our current jargon.

It does contain many, many memes, which - along with emojis - are the hieroglyphs of our time. There are certainly worse legacies I could leave.

I have often thought of how strange it would be to watch HD video of ancient people like the Romans, and wonder what that experience will be like for future archaeologists. Assuming any of this survives the next few thousand years.

In theory they would be able to determine they were a much later addition. Then again, things like ancient Egypt lasted for thousands of years, so perhaps they will consider 2000 years a short amount of time.

That said, it does feel like the past few centuries (since the Industrial Revolution, but even moreso since the late 1800s/early 1900s) have seen incredible avancement in technology, unlike anything seen before. I mean electricity as we know it - the means to reliably generate and use it - have only been around for just over 200 years now.

The company that makes them: https://www.dyaqua.it/invisiblesolar/_en/

> Inside the module there are incorporated standard monocrystalline silicon cells. The surface, that is opaque at the sight but translucent to sun rays, allows the light to enter and feed the cells.

When they talk about "sun rays", do they mean the UV portion of sunlight? Because if the material were transparent to visible light, it would be, well, transparent, wouldn't it?

Monocrystalline Si has a 1.2 eV band gap iirc, meaning it absorbs everything smaller (more energetic) than ~ 1100 nm.

Our eyes see, what, 200-600 nm? Removing the 200-600 nm bit leaves you with approx 50% of the energy left between 600 and 1100 nm, glancing at [1]

This is all VERY back of the envelope... but I think these lose around half of the energy you'd get out of conventional panels.

[1] https://www.researchgate.net/publication/303914764/figure/do...

Here's a plot [1] of PV power, over the whole spectrum. Your envelope appears to be of high quality.

It's unfortunate they don't just have actual numbers on their website, which is a pretty terrible indicator, especially with the orientation of the panels being around 45 degrees.

[1] http://environmath.org/wp-content/uploads/2020/12/spectral_l... from http://environmath.org/2020/12/17/why-solar-panels-cant-get-...

Human visual range is generally 400-700 nm, although some small responsiveness remains up to 800 nm and down to 360. Below 400 nm is usually considered ionizing radiation.

But even a ~20% reflection coefficient can make something appear "opaque" if viewed in sunlight and complete darkness behind it.

Good point! You don't need to block the light completely -- I hadn't thought of that!

The specs show it as .11 efficiency, and normal panels are about .22, so like litterally 1/2. That's pretty darn good for being visually appealing.

on the other side, normal panels will usually cover part of the roof. those tiles will cover entire roof. hence even if efficiency lower, total output will be higher

I agree, effeciency is only a concern as a function of space available.

If you have a flat roof then all the space is available, and depending on your latitude flat can be a good orientation, especially in summer.

Pompei roofs do not appear to be flat, but they do seem to be very low pitch, and the panels are curved, so the whole roof is likely in play.

Back to your main point, effeciency in itself doesn't matter. If you have enough space, you just install more. That drives up the installation cost though, and things like cleaning them etc.

Of course ultimately everything is space constrained, but generating 11% is better than 0%.

It's possible to install more panels, but in many cases it's harder to get coverage of more than 50-70 % of the roof due to it's geometry/multi-slopeness/vents/etc.

Nice maths.

For the benefit of the audience: if you imagine picking a point on that curve and drawing a square under and to the left of it, a solar panel captures only that energy from the orange region. Photons with longer wavelengths aren't captured: not enough energy to push an electron up the bandgap. Photons with shorter wavelengths have more and more energy to push an electron up, but can only capture 1.9226e-19 joules per photon of that energy at 1.2eV.

>When they talk about "sun rays", do they mean the UV portion of sunlight?

I don't think so, because they say they use a standard monocrystalline siicon PV cell -- which are (generally) crappy for UV scavenging.

I would guess the material atop the solar cell is either slightly porous or made of a material that is mostly transparent to the right spectra of light, resulting in acceptable losses.

You could get away with scattering 30% of the red light and have it look opaque. Letting most of the rest through.

This would be great if they can do more styles and not just terracotta. E.g. I own an "old" UK home that has a "normal" tiled roof, but as it is in a conservation area so any attempt at solar will be met with literal outrage. These would be great even if they are only 10% efficient - something is better than nothing and I have this big old roof sitting there and the whole thing could be one huge solar panel.

Where can I buy these that match UK 100-150 year old standard UK housing styles? I have my credit card ready.

FTA they can be made to look like stone, wood, concrete or brick.

Seems like a great idea especially in the places where you need to match the style of buildings or cant change outward appearance.

Thatching might be difficult though...

While low efficiency will definitely be great for renewable power generation, it'll be a tradeoff - cost / benefit, mainly. How expensive is a solar roof vs regular tiles, how often does it have to be replaced / maintained, and what is the cost of production and end-of-life?

I think this is definitely coming, but it takes time or lots of money or both for a product to arrive on the market.

These terracotta tiles (which are popular in the 1950s-1970s area I live) seem to have proprietary connectors and cabling which complicates installation, regulatory compliance and repair.

I was thinking the same thing! I've also an old UK home were putting panels would be awkward if not impossible.

edit: it is not surprising that they focus on terracotta tiles as those are really common in Italian homes.

They can be designed to appear like stone, wood, concrete or brick, so can be hidden on walls and floors, as well as on roofs,

Somebody wanna run the numbers and tell me how many decades it will take for one of these things to offset its manufacturing & installation carbon footprint? I'm betting it's a while.

The answer for traditional solar panels is about 2 months IIRC.

The answer for these should be significantly less, because you should only count the delta between solar tiles and non-solar tiles rather than the entire footprint.

> The answer for traditional solar panels is about 2 months IIRC.

Do you have a citation for that? A quick Google said normal panels take three years.

The carbon footprint idea seems flawed to me. It always just depends how far you look. There are machines making machines making machines and so on, the chain is really long and those early machines in the chain, which may have been necessary to create given product, may not even exist anymore. They might have existed before the product was even invented.

Note that the whole idea was mostly popularized by BP [1][2].

1. https://en.wikipedia.org/wiki/Carbon_footprint 2. https://www.theguardian.com/commentisfree/2021/aug/23/big-oi...

No, I couldn't find it again, it was just from memory. But a check on your number shows that it came from 2004. The price of solar panels has dropped ~90% since 2004, and price is fairly well correlated with carbon footprint.

> The price of solar panels has dropped ~90% since 2004, and price is fairly well correlated with carbon footprint.

Part of that low price was China flooding the market with cheap subsidized cells in other to take the competition out of business. Similar to the way Amazon puts the prices (of products and prime) up in markets where they've already eliminated most of the competition.

I don't think actual energy footprint has reduced by that much, I'm sure it has a bit though.

Frauenhofer pv report says 4 months to 3 years EPBT depending on travel distance, grid losses (both in manufacture and generation) and install location. If you install on a single axis tracker in Chile and use the energy DC then 2 months is believable. These lose about half the light, so up to six years assuming the decorative tile part is negligibly higher carbon than what would go there anyway.

>> …only count delta…

Not if replacing tiles that would otherwise not be replaced.

Yeah terracotta tiles last over 100 years so it’s well worth factoring in.

I'm waiting for one good hail storm to finish off my roof as far as the insurance company cares.

This "but the energy cost is net negative against keeping what we have" is an odd basis of reasoning. Some days I think its just a modern variant of "we should never have come down out of the trees" thinking.

No development can get away from a positive energy burden against the sunk cost of history. For active (coal burning power) vs passive (solar) the net energy cost is probably always good now: the cost of deploying solar has dropped enough that the sunk cost of the coal burner is now exceeded by the future lifetime upside of the PV, even given its carbon debt to make.

You're in a niche, arguing that scavenging existing clay tiles and keeping what you have is net better carbon output (bearing in mind your power has to be generated, and transmitted) than replacing the tiles with solar tiles. Thats different to 'replace coal burner with solar' but it can be calculated.

TL;DR you're asserting you think its worserer. I think its an interesting question, I don't actually think it is, but if it was, the question doesn't terminate in the sunk cost of the existing tiles, its the sunk cost AND FUTURE BURDEN of the coal burner you don't use. It's not just the production cost burden of the solar PV tiles, you have to remember to include the CO burden from the energy source you don't displace by making it locally.

The last I looked (2019-ish) the carbon footprint offset for the whole installation I was planning was 1.9 years. The lifetime is ~20-25 years.

I tried to include everything, panels, inverters, aluminium rails, transport etc.

Things have evolved significantly so my guess is that this has come down a lot.

This tech would be amazing for anyone slapped with a random heritage listing do not modify ban on installing PV, as has happened here in Melbourne, VIC.

E.g. https://www.pv-magazine-australia.com/2022/06/08/melbourne-h...

Agree. In Spain, most councils do not allow solar panels to be installed on houses in the old town. My uncle has to take them out...

It is no surprise this tech is from Italy. At least in Europe this is the main reason you do not find solar panels in cities.

Is reducing the amount of light that these panels receive likely to increase their effective lifetime? Or: Does total energy absorbed dictate decay of solar panels? Does that affect EROI calculations?

Light-induced degradation of silicon-based solar cells generally saturates above 0.1 suns [1] for the predominant mechanism of boron-oxygen defect formation; thermal degradation is also a factor [2] and likely to be unaffected by this geometry. But ERoEI for solar cells can be high, even in Europe [3] so, considering the roof replacement as a necessary cost regardless, these may still work out favorably, but at this juncture, only for special applications.

1: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.69.02...

2: https://www.sciencedirect.com/science/article/pii/S136403212...

3: https://www.sciencedirect.com/science/article/pii/S030626191...

The amount of light does decay the solar panels. But it is not the only thing causing degradation. I believe the other large item for degradation is thermal. Operation at higher temperature induces degradation faster and there is some degradation from thermal cycling. So if the covering also keeps it cooler and at a steadier temperature then it is probably good. But the covering might also cause some greenhouse effect that causes it to operate hotter. So...maybe?

Lightly discussed 1 month ago:

https://news.ycombinator.com/item?id=34286801 (4 comments)

Didn't Tesla initially have a plan to disguise solar panels as slate?

Yes, the Tesla Solar Roof tiles, and they did get some tiny number (thousands or something like that?) installed. I actually had ordered one and was in line to get it installed last year. But the company cancelled it, and then Tesla started cancelling all of them apparently. The reason the installer gave was that the v1/v2 were too labor intensive to be worth it, and they were waiting for the v3, but from reports I read another factor is that Tesla has been completely putting most of their solar stuff on the backburner due to internal dysfunction and redirecting all resources to car production. They've blown off a lot of the promises they made to New York at least for production and from the sound of it it's all a big mess. Which is too bad because from what I saw in person the product looks very good, and installations in Florida survived some big hurricane winds last year. So the durability seems to be as advertised vs wind/hail. And I do care about that on my roof of my house. But it appears to not have been at all a real internal priority.

As it happens I found this exact Italian company a few weeks ago trying to research if anyone else was trying to do the tile approach and was excited that there's at least something, even if they're a long time away if ever from any sort of global scale. But it's an approach I'd really like to see as part of the mix. Just driving around and looking, it's obvious people care about how their homes look. Since technologically it's feasible to have aesthetic solar power, it'd be nice to have a bunch of good options there just as there are for traditional roofs.

As far as Tesla, I wonder if they may come to regret burning some bridges and reducing their early lead/mindshare/diversification. The recent crashing prices for car EVs as other players pile into the space shows some of the risk, I bet they wished they'd put more effort into getting the Cybertruck out right now. They may ultimately feel the same about solar and home/business energy. I've got PowerWalls and are mostly happy with them, but I'm very interested in some of the vanadium redox flow batteries getting developed (like by StorEn) as well. Tesla has had an early lead but I think they could easily still squander that.

Did you ever end up finding any other company making any tiles that resembled slate, out of curiosity?

The Swiss company Meyerburger will bring solar tiles this year to the market https://www.meyerburger.com/de/solar-tiles-intersolar-lp

There is a reference here (for UK):

https://news.ycombinator.com/item?id=34286801

Ah, so close... the roofs in my area are all reddish-brown and a different color will clash with the local conservation area constraints. But maybe by the time I have to replace my roof (which is soon) they might have the right color.

Hum, thinking of it, there are solar panel exceptions to the constraints, as long as they are flat on the roof...

Yes multiple companies do this now.

This is a valid question, idk why you're being downvoted.

You're thinking of SolarCity which was bought by Tesla. There were promises of these kinds of solar cells that I was excited about. Not sure what ever happened to them.

I don't know about initially, but yes, Tesla has a solar tile project. It is mostly being installed by third parties now and is very expensive compared to an asphalt roof with panels.

https://www.tesla.com/solarroof

At announcement, different designs were available, but in the end I think they've only offered slate.

They got it as part of rescuing SolarCity, which made little sense as a business move from Tesla, but was owned by Musk's cousins so he decided to gift them 2B$, let it go a bit, then abandoned the project.

They are still being installed. Its not an abandoned project.

If it indeed delivers what's advertised, it appears they outdid Tesla's "Solar Roof", and actually have a de facto obtainable and better-looking product for delivery!

However, it seems to cost some ~4x the normal price per W of solar panels.

- Could mass production of these and economies of scale reduce the price to more competitive levels?

- And how long for a typical installation of these to recover the investment, aka: "Payback Period"?

(is it the same as ROI?)

They look cool and all, but how much does this cut down on efficiency?

I guess that doesn't matter much as long as it pushes customers who would have never otherwise used such things to do so at all.

in other words, for historical sites or places where aesthetic matters a lot, the conversation is "should we use these less efficient panels that fulfill our aesthetic requirements, or should we forego the use of solar all together?"

Major chunks of Italy are basically outdoor museums that people happen to live in, so even if the math doesn't completely pencil out on these particular first generation panels, it still probably makes sense as a long-term investment to ensure that the next generation of this technology for which the math does work comes into being.

If EROI on those panels is negative then it's better to forgo them.

I agree -- but the picture is often more complicated for places that rely heavily on tourism and marketing.

The image portrayed by a tourist destination that is making large efforts towards 'green initatives' may be a more enticing sell to the increasing number of 'eco-tourists', many of which have never thought a day in their life about EROI.

This is more of a specialty item where you don't want to trench a power line through an archeological site. You can get enough power for basic lighting with a small solar installation.

I appreciate that you are calling it straight, but it's worth pointing out that there are others who see eco theater as incredibly harmful, particularly when such things start to cannibalize public resources and funding. Take, for example, all current and past solar roadway projects.

I also want to be clear that I am not passing any judgement on these tiles. I don't know the economics or the funding of this project in any way. But it does seem to have plenty of indicators for being a boondoggle.

Even if it's negative it pumps money into the designer solar panel sector which will bring in further investment and research and scale to bring prices down.

Which is useful only if it also eventually makes EROI positive - otherwise, upping the scale and bringing prices down is only accelerating waste.

Since the article fails to compare their efficiency with traditional power cells, I am betting that it is a small fraction of the alternative. If these things were something like 80% as efficient or higher, I'll bet that would have been in the first or second paragraph.

Apparently they are half as efficient compared to conventional cells.

So cool. I hope this scales well.

You, my friend, get an upvote for what is almost a pun!

These would look great in Arizona. Anyone know the ballpark for roofing a McMansion? Their site doesn’t have pricing.

Shipping from Italy is too expensive, but maybe if you find a few customers and batch-order at economical scale?

This page has pricing: https://www.dyaqua.it/invisiblesolar/_en/rooftile-invisible-...

Looks like 7k euros for I think that is 9 square meters. Not sure what a typical solar install goes for now, but based on this it would cost 70k just in materials for my 1k sqft roof. Doesn't seem economical.

> 1k sqft

I know what you mean, but at first glance this looks like an unholy matrimony of metric and imperial.

$7000/kw which is 140 tiles. So around $50 a tile. Don't know the size of your mcmansion.

But a youtuber told me a shade of an ivy leaf on a solar car will bring the whole array to a trickle, so any installation should be spotless and free from shadows. Any truth to this, since the tiles are going to be stacked and maybe under shade partially?

The are that's going to covered by the next tile when stacked is well known in advance. Obviously solar cells are not installed in this area. As for the shading from leaves or something, typically diodes are installed in solar panels to prevent current flow into the shaded parts. This helps mitigate the power loss from shades.

Artisanal production - nope nope nope nope nope

Give me a lights-out factory without a single human being churning out a gazillion units per day with 100% test coverage please. Anything else will have all kinds of quality control and reliability problems when trying to produce a bunch of nominally-identical widgets.

It's a niche product for a very specific environment.

Actually it is a very small scale experiment for a very niche product.

Hopefully not for long.

The best technology is invisible

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