[HN Gopher] Solar panels disguised as terracotta tiles in Pompeii
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Solar panels disguised as terracotta tiles in Pompeii
Author : odewahn
Score : 123 points
Date : 2023-02-09 18:45 UTC (4 hours ago)
(HTM) web link (www.theartnewspaper.com)
(TXT) w3m dump (www.theartnewspaper.com)
| causi wrote:
| _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.
| [deleted]
| bryanlarsen wrote:
| 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.
| ant6n wrote:
| >> ...only count delta...
|
| Not if replacing tiles that would otherwise not be replaced.
| jkmcf wrote:
| I'm waiting for one good hail storm to finish off my roof
| as far as the insurance company cares.
| jahewson wrote:
| Yeah terracotta tiles last over 100 years so it's well
| worth factoring in.
| teruakohatu wrote:
| > 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.
| bryanlarsen wrote:
| 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.
| unit_circle wrote:
| 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?
| scythe wrote:
| 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...
| dr_orpheus wrote:
| 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?
| r3trohack3r wrote:
| These would look great in Arizona. Anyone know the ballpark for
| roofing a McMansion? Their site doesn't have pricing.
| TEP_Kim_Il_Sung wrote:
| Shipping from Italy is too expensive, but maybe if you find a
| few customers and batch-order at economical scale?
| pard68 wrote:
| Didn't Tesla initially have a plan to disguise solar panels as
| slate?
| warent wrote:
| 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.
| xoa wrote:
| 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.
| 1270018080 wrote:
| So cool. I hope this scales well.
| einpoklum wrote:
| You, my friend, get an upvote for what is almost a pun!
| metadat wrote:
| Lightly discussed 1 month ago:
|
| https://news.ycombinator.com/item?id=34286801 (4 comments)
| burkaman wrote:
| 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://integrate
| dpv.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.
| kristopolous wrote:
| That's fine, they look great. Realizing we've got stuff looking
| like that that generates freakin' electricity is amazing.
| UncleOxidant wrote:
| They look cool and all, but how much does this cut down on
| efficiency?
| serf wrote:
| 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?"
| TeMPOraL wrote:
| If EROI on those panels is negative then it's better to forgo
| them.
| serf wrote:
| 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.
| Animats wrote:
| 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.
| gorkish wrote:
| 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.
| elgenie wrote:
| 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.
| didgetmaster wrote:
| 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.
| mgerdts wrote:
| The company that makes them:
| https://www.dyaqua.it/invisiblesolar/_en/
| xg15 wrote:
| > _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?
| isoprophlex wrote:
| 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...
| whydoineedthis wrote:
| 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.
| scythe wrote:
| 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.
| nomel wrote:
| 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-...
| serf wrote:
| >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.
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