Truly sustainable solar panels

Solar panels have always bothered me because they require such intense manufacturing and usage of scarce resources. TLDR of article: “Many people will argue that if low-tech solar panels are less efficient, we would need more solar panels to produce the same power output. Consequently, the resources saved by low-tech production methods would be compensated by the extra resources to build more solar panels. However, efficiency is only crucial when we take energy demand for granted, sacrificing some efficiency may gain us a lot in sustainability.”

activistPnk, (edited )

PBR ran a documentary that showed how solar panels were made: by “smelting” quartz with coal, and the harmful emissions from that process which are overlooked in most conversations around solar panels. So indeed this older design of just using two dissimilar metals seems superior in terms of production.

skyfaller,

Worth reading this investigation into the historic photos: bellingcat.com/…/untangling-the-mystery-of-the-wo…

Also worth pointing out there is some question as to whether these solar panels ever functioned. Someone should build one to test it out!

perestroika, (edited )

The article has a slight oversight - it is a bit behind the state of the art.

S. Korea develops technique to recycle discarded solar panels into high-performance solar cells

South Korea moves forward with long-expected solar panel recycling scheme

Reclaiming the aluminum has been possible for a long while. Reclaiming the glass has been “not worth the effort”. Reclaiming the doped silicon is apparently a reality in South Korea, however.

As for the story itself, wow - very interesting. :)

“My hypothesis is that George Cove stumbled upon a Schottky contact photovoltaic cell, decades before it was described by Walter Schottky. 21 There is the possibility of both photovoltaic (predominantly) and thermoelectric responses from these devices. The plug was an alloy of zinc and antimony – which we now know is a semiconductor. It was alternately capped by German silver (a nickel, copper, and zinc alloy) and copper on opposite ends. This formed an ohmic contact and Schottky contact, respectively. This is a photovoltaic device.”

According to Philip Pesavento, George Cove probably started with “German silver” as the negative material on both ends of the plugs, and an antimony-zinc alloy (ZnSb) as the positive material. These were the best available thermoelectric materials at the time:

“He probably ran out of German silver and substituted copper to finish making up a bunch of plugs since the difference in thermoelectric voltage between using copper and German silver was small. Then, during testing, Cove noted that these plugs (with a German silver cap at one end and a copper cap at the other end) gave a much greater voltage: 100s of mV’s versus the usual 10s of mV for a thermoelectric generator.”

evasive_chimpanzee,

To put some numbers to things, using this calculator, I could generate ~14,000 kwh per year with typical panels on my roof. According to wikipedia, the average US household uses ~17,000 kwh per year of energy (n.b., not electricity). 3/4 of that is HVAC. An air-source heat pump might have a coefficient of performance of 5, in which case the actual electricity requirement would be 7,000 kwh per year.

Basically, I could generate double the average household needs, so I could deal with a hit to panel efficiency. Granted, that’s only for domestic energy consumption. If you factor in things like food production, transportation, water treatment, etc, my consumption would be higher.

JohnDClay,

Couldn’t we decrease demand with more efficient solar panels too? It seems like the critical tradeoff here (given unlimited space and funding, which is actually important) is the environmental cost per kwh energy produced.

ecoelectrify,

“Environmental cost” is a very vague concept. If we only consider carbon emissions, more efficient panels might be better. But factoring in the waste generated over time, the lifecycle impacts of the panels (mining, manufacturing, disposal, etc.) I think there needs to be more analysis. Not saying it will outweigh, I just think its worth a hard look.

In terms of decreasing demand, that’s a consumer-side factor, so it has no connection to actual panel production.

benjhm,

We prefer the most efficient solar panels where space is limited, such as rooftops, however there are vast areas of the earth that are almost unused sunny desert, perhaps there low-tech could make more sense?

ecoelectrify,

Yep this makes sense to me, I agree. Especially if those vast areas are far from large manufacturing facilities of these efficient panels (likely), less complex and DIY panels produced on site would reduce transportation costs. It would just be a matter of locating materials in those regions.

schmorpel,

Please be careful with terms like “unused desert”. Whatever “green” developers call unused land is usually some kind of ecosystem with an established community of human and non-human inhabitants. They are forced out and big “green” money moved in, with their hydro, wind, solar, lithium mining …

Forest mountain landscape not far from here will be torn up for another green tech, lithium, because those who can afford it want to get to nice forest mountain landscapes in their eco cars, for their eco holidays. Pasture lands not far from here are now filled with the stupidest of solar installations: nothing but panels. They could have the same old herds of before clean the land between the panels, but instead its all fenced off and probably treated with roundup, or motorized machines. And people want more cars, more air conditioning because every summer it gets hotter, and the spiral of “ever more” continues.

Calling arid or not obviously landscaped spaces far away from you “unused” is dangerous and will expose the last wild landscapes of earth to abuse. It’s bad enough as it is.

activistPnk,

Some species are winners and some are losers when people tamper with the environment. You make it sound like there are only losers. Maybe the shade of panels would help some plant and animal species thrive that would enrich the ecosystem. It would of course need careful analysis to avoid disaster.

Ben’s idea is in the very early brainstorming phase so shouldn’t be cancelled on the off-the-cuff assumption that an intervention would necessarily be reckless.

benjhm,

Well I was thinking of the central Sahara, and parts of Arabia etc., these areas really are vast. Sure it would change the landscape, but not so much life. It may be better to make cheap (the op is about low-tech) electricity there, than for example get to 1.5ºC pathways by BECCS (generate electricity with biofuel from plantations, then pump CO2 underground) which is much worse for biodiversity. Your examples - forest mountain, pasture - wouldn’t be called desert - at least not in english (the interpretation may vary with language), it’s a more extreme term than arid.

activistPnk, (edited )

If solar energy is collected from such remote areas, is there perhaps a show-stopping problem of transmitting that power out to city? Transmission has huge losses over great distances.

There was a recent proposal to cover train tracks and (I think) some segments of rivers with solar panels. One of the problems IIRC was transmitting the power. My memory is a bit fuzzy on it… not sure why they couldn’t just directly power the electric train that runs below them… but whatever the issue was, it might be the same issue as the desert would have.

Your examples - forest mountain, pasture - wouldn’t be called desert - at least not in english (the interpretation may vary with language)

You can’t really trust layperson’s common English here. There are vast forests which are not being tagged as “forest” because a majority of trees don’t reach a certain defined height. These non-forests are useful for decarbonization but they’re being cleared on the basis that they are not technically a “forest”. So now there is a movement to protect these non-forests.

benjhm,

Re transmission - yes there are increasing losses - but the OP is about cheap panels, so cheap electricity. It doesn’t have to go so far, for example I’m thinking that the population in the Sahel is projected to increase a lot - that highest fertility in the world, as these regions develop they’ll need electricity.
As for your non-forest, I’d call that scrubland, certainly not desert - which implies to me sand or bare stones, deserted by almost all life not just by people. Of course flowers can bloom even in the desert on occasional years after rains. Indeed the whole Sahara was much greener, only a few thousand years ago, and maybe could be again if we could work out the secret. But that’s still a perturbation, and even with solar panels, there’d be plenty space left.

SomeoneSomewhere,

Transmission does not have excessive losses. They’re typically well under 5%. Even in grids with lots of long distance transmission (NZ has lots of generation in the south island, demand in the north island), the last-50-km losses are higher than the long-distance losses.

Rail current draw tends to be very bursty including both consumption and regen, with capacity that is quite limited on longer lines. The amount of power that can be connected isn’t very large, and because it’s a very long, narrow corridor, the average distance from a panel to an inverter is going to be large, or the inverters are going to be small.

Railways also like to regularly shut off the power to make maintenance safer and faster, and just use other tracks or diesel trains. This would interrupt the generation.

Mechanical mounting and windage concerns could also be present; a structure overhead could affect the aerodynamics of particularly high-speed trains, and the roof could funnel crosswinds into the train rather than over the top.

I’m not sure it’s impossible, it’s just that there are still much better places to put panels.

iraq_lobster, (edited )

that website is still alive ? how nice

also we need to achieve net positive: pv panel factories need to be fully powered by solar, else a panel would always carry some carbon footprint

activistPnk,

I love how that site is not in the slightest enshitified, just as we would expect for something with low-tech in the name. No CAPTCHAs or popups, cookie walls or other bullshit. Very hard to find good websites like this. Search engines should give that site a top ranking.

ecoelectrify,

agreed, it is a fantastic website. I wish there were more like it.

I ordered their paperback magazine, which can be printed on demand. Looking forward to reading it

anothercatgirl,

something about the curse of competence, that our solar panels will increase daytime energy use without reducing emissions by much, if we don’t fight the idea of consumerism and unlimited energy.

iraq_lobster,

the sun is unlimited, at least in your lifetime. also is the cold of the void

schmorpel,

The space we can fill with solar panels and the resources used to build them are not unlimited though.

iraq_lobster,

for a country like France, you would need only 5% of its surface to cover its energy needs (this is at 200w/m²). say the sustainable panels would be half efficient, you would still need only 10%.

schmorpel,

Okay, and I see a thousand places where I would consider solar panels well placed. Every house, every shed, parking place, road … should have panels on top. Some mountain areas can have them. They can provide shade for useful crops in more arid places. All of these are small scale and combined uses though, and the companies currently promoting and building solar here in Southern Europe are buying up farm and pasture land instead and filling that with panels, in a way that makes no sense.

I think it has to do with the way subsidies and grants for projects are organized. It’s very difficult and complex to submit a mixed project to ask for EU money for your project. You can’t go and say “I want financing for this project, where I have these few fruit and olive trees, 50 500W panels, blueberry plants and garden under the panels, and fifty sheep on 15ha land.” The guys in the subsidy office will give you that toothache face and go “errr” and what you end up with is projects with 1000 panels and nothing else, or 100000 trees of one kind and nothing else, or 1000 sheep and nothing else. Each business artificially kept alive on behest of enormous energy and work inputs - blueberry plants with elaborate shading structures. Tree rows kept clean with help of machinery and pesticide. Solar panel rows cleaned in the same way. Trees artificially fertilized. Everything separated becomes mega energy intensive, very wasteful, but bureaucracy likes it simple, and people can’t or don’t want to move without EU financing.

iraq_lobster,

tbh there is nothing profitable about building solar farms, since its a ‘socialist’ measure and can only be achieved by a goverment. Utility companies like to intervene only when there is profit to be made, mainly by distributing power. Personally i dont think solar is fit above agriculture land but rather on a remote 0 purpose land. For the french case earlier, it would amount to 277000km², which is still miniscule and some fertile land could be sacrificed for such endeavour. And yea, corporates always like gov handouts: like to take everything and prefer to give back the least possible

MrMakabar,

The problem is that solar has to replace fossil fuels, instead of being additional to fossil fuels. That is not going to work on a global scale, if we continue to use more and more energy to have a fast growing economy. At least the wealthy countries have to stop growing energy consumption and even lower it, to make it possible in a reasonable timeframe to go to net zero.

Long term we have enough of it, since solar panels last a long time and sunlight is basicly limitless. However that is long term. Short to mid term it is limited by the number of panels we have.

iraq_lobster,

also passive carbon sequestration is needed, aka forestation: actively trying to sequestrate carbon is stupid. depopulation is also needed, and GDP’s is to be lowered too

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