[HN Gopher] Scientists Develop Artificial Leaf, Uses Sunlight to...
       ___________________________________________________________________
        
       Scientists Develop Artificial Leaf, Uses Sunlight to Produce
       Valuable Chemicals
        
       Author : gnabgib
       Score  : 268 points
       Date   : 2025-04-24 22:10 UTC (1 days ago)
        
 (HTM) web link (newscenter.lbl.gov)
 (TXT) w3m dump (newscenter.lbl.gov)
        
       | changoplatanero wrote:
       | Something I'm curious to know: How does the efficiency of this
       | new process compare to using regular solar panels to generate
       | electricity and then using that electrical energy to synthesize
       | the same chemicals?
        
         | bognition wrote:
         | Efficiency is likely much lower than solar panels, however,
         | solar panels are expensive and complicated (chemically) to
         | manufacture. Teaching plans to make stuff for us is a better
         | long term solution as we can just grow the plants.
        
           | turtlebits wrote:
           | What? Solar panels are cheap and little to no maintenance.
           | Even though wildly inefficient, I opted to heat water using
           | PV instead of a solar hot water because of how low complexity
           | it is.
           | 
           | Also, nowhere in the article does it mention growing these
           | artificial leaves, they probably need to be manufactured.
        
             | pfdietz wrote:
             | I roll my eyes at these "artificial leaf" claims for just
             | the reason you've identified.
        
             | trollbridge wrote:
             | Solar panels have a limited lifespan, decrease in
             | efficiency over time, and also get ruined when things like
             | hail happens. This doesn't mean PVs are a bad idea, but
             | it's not accurate to say they have little to no
             | maintenance.
        
               | dwattttt wrote:
               | Aside from the hail, none of those are maintenance
               | requirements. I've done 0 maintenance on my panels over
               | their lifespan.
        
               | msy wrote:
               | 'Replace every 15-20 years' is not maintenance. Neither
               | is replacement in the case of catastrophic weather events
               | that'll have you replacing all your windows as well. The
               | only 'maintenance' solar panels benefit from (which is
               | still entirely optional) is occasional cleaning.
        
               | fc417fc802 wrote:
               | To be fair your windows are less likely to take the full
               | brunt of an extra large hailstone since they're usually
               | mounted vertically.
        
               | fc417fc802 wrote:
               | Sure but how do these artificial leaves fare when
               | analyzed with the same criteria? Presumably worse, given
               | that solar panels are (roughly speaking) nothing more
               | than a few sheets of material laminated between glass
               | panels.
               | 
               | Artificial leaf is an alternative term for extra
               | complicated solar panel.
        
               | gus_massa wrote:
               | If you ignore the nice " _Artistic depiction of an
               | artificial tree_ " it looks like this will also be " _few
               | sheets of material laminated between glass panels_ ", but
               | I'm worry it will also need plumbing for the water and
               | output gas.
        
               | xbmcuser wrote:
               | 20 year solar panels just loose 5-10% capacity and
               | degradation slows over time the reason most people
               | replace them today is 20 year old panels were 200w where
               | as today panels are 5-600w.
        
               | Ygg2 wrote:
               | Sadly our solar panels don't self heal or come with
               | 100(0) years warranty.
        
         | trollbridge wrote:
         | [flagged]
        
           | dwattttt wrote:
           | Make sure to include the time and inputs to make the grass,
           | and especially trees; those don't just appear out of nothing.
           | And we already know how it works, it's called logging.
        
             | lithocarpus wrote:
             | None of the inputs required for plants to grow require
             | toxic pollution or destructive extraction.
             | 
             | Of course humans can bring in toxic or destructive inputs
             | to try to favor certain plants over others, or humans can
             | do other non destructive things to favor certain plants
             | over others. Or humans can step aside and let the plants do
             | their thing which will create abundance too. (I like the
             | middle of these three.)
             | 
             | Also, trees provide far more value than timber alone.
        
               | ashoeafoot wrote:
               | Would you give up fertilizer and pest control and stop
               | feeding the 8 billion ?
               | 
               | Please dont be a holdomorehippy.. Those back-to-nature
               | loving massmurderers without a cause creep me out beyond
               | repair.. those that openly hate some humans at least give
               | the monstrous game away.
        
               | trollbridge wrote:
               | Eventually, you won't have a choice when fertiliser
               | produced from oil runs out, becomes cost prohibitive, or
               | is made illegal due to greenhouse gas problems; likewise,
               | "pest control" has already resulted in a 40% decline in
               | insect populations; it won't be good if it gets to 100%.
               | 
               | It would be best to find sustainable ways to grow food
               | now, instead of continuing unsustainable ways (including
               | supplying massive food aid to unsustainable populations
               | so they can keep growing) until there is a precipitous
               | crash.
               | 
               | The idea that only industrial scale farming can feed the
               | planet is mostly a myth promoted by producers of
               | industrial scale inputs and the oil/gas industry, by the
               | way.
        
               | pfdietz wrote:
               | > Eventually, you won't have a choice when fertiliser
               | produced from oil runs out, becomes cost prohibitive, or
               | is made illegal due to greenhouse gas problems
               | 
               | You mean, aside from the process of making ammonia using
               | green hydrogen that doesn't use fossil fuel at all? A
               | process that can be sustained indefinitely, using
               | renewable energy?
               | 
               | The single big concern is nitrous oxide emission from
               | bacteria in the soil, but that can be reduced by
               | nitrification inhibitors, some of which can be produced
               | naturally by plant roots (and likely engineered into crop
               | plants.)
        
               | lupusreal wrote:
               | Fertilizer is mainly made from natural gas, not oil.
               | Accordingly it should last much longer. Worse case
               | scenario when we run out is we switch to less efficient
               | production, for instance splitting water using nuclear
               | power.
               | 
               | Any plan that relies on depopulation isn't going to work
               | and any attempt to force it to work would require crimes
               | against humanity.
        
               | mapt wrote:
               | The production of concentrated nitrogen compounds from
               | thin air is useful enough that we'll almost certainly
               | keep doing it en masse in an electric-only future.
               | 
               | Mining for phosphorous and potassium fertilizers,
               | likewise, but situationally a little different because
               | these aren't very mobile in the groundwater column like
               | nitrogen is, and they don't offgas back into the air like
               | nitrogen compounds do. Quite possibly we'll be mining
               | manure lagoons more, for CH4 and for closing the loop
               | better on P and K.
               | 
               | Ag will continue at industrial scale for cereal grains,
               | because half the population is not going back to the
               | fields.
               | 
               | Within that framework, there's a lot of difference
               | between outcomes in terms of how green we make our farms,
               | what we grow, how we grow it. Herbicide and insecticide
               | practices do not have to be what they are, as we witness
               | massive overuse of things like neonics, glyphosate, and
               | aminopyralid mostly because there's little financial
               | reason to constrain use. We could stand to dramatically
               | reduce the amount of cereal grain we consume, from a diet
               | perspective, but the logistical difficulties of
               | alternatives like more fresh fruits & vegetables will
               | tend to increase carbon emissions. Eating less grain-fed
               | meat and more high-protein legumes is basically a win-win
               | from diet and climate perspectives. Returning to a less
               | industrialized industry where livestock are raised on
               | farms instead of on "feeding operations" seems like a
               | fair tradeoff against something like subsidized corn-
               | ethanol production. Attempting to encourage long-term
               | soil stability with reduced tillage and is another goal
               | that we might tangle with that would reduce yields; We
               | have plenty of yield to spare in the US, so this is an
               | option.
        
               | xhkkffbf wrote:
               | To be a pedant, the inputs for photosynthesis are pretty
               | toxic to humans. Sunlight burns and causes skin cancer.
               | CO2 also kills people each winter when space heaters
               | aren't properly vented.
        
             | trollbridge wrote:
             | Whose time and what inputs are required to make grass and
             | trees? If you simply leave a place alone, it will turn into
             | either a forest, a grassland, or desert (the latter when
             | human activity has thoroughly destroyed it).
        
           | chongli wrote:
           | I'm just picturing whole new swathes of rainforest being
           | clearcut and bulldozed to make way for "artificial leaf
           | farms."
        
           | joak wrote:
           | Imagine you have 100 acres growing corn for biofuels, would
           | it be nice to replace these by 99 acres of wilderness and 1
           | acre of photovoltaics producing the same amount of biofuels?
           | 
           | If your photovoltaics are 100x more efficient to produce your
           | chemicals, agriculture is the dirty way of doing it.
        
             | saretup wrote:
             | Does it mention it's 100x more efficient anywhere? Or is it
             | just an example you're providing, in which case, why not
             | 1000x?
        
               | joshuaturner wrote:
               | > why not 1000x?
               | 
               | now we're talking - can I invest in your company?
        
               | spauldo wrote:
               | Corn isn't particularly great for producing ethanol. I'm
               | guessing that a synthetic process won't be able to get
               | close to 100x less land usage, but any improvement would
               | be welcome.
               | 
               | The problem I see is that there's not enough money in in
               | to develop a new process. Cellulosic ethanol outperforms
               | corn on nearly every measure, but there's not enough
               | money in it to pay for the development needed to scale it
               | up to industrial levels.
        
               | ZeroGravitas wrote:
               | They might be remembering the stat that:
               | 
               | > Looking at land-use efficiency, corn-derived ethanol
               | used to power internal combustion engines requires about
               | 85x (range: 63-197x) as much land to power the same
               | number of transportation miles as solar PV powering
               | electric vehicles.
        
               | thaumasiotes wrote:
               | What's that supposed to be relevant to? We don't make
               | corn-derived fuel because it's cost-effective. It isn't.
               | The idea is to give corn farmers something to do, which
               | won't work if you reduce the amount of corn you're
               | growing.
        
               | mapt wrote:
               | We make corn-derived fuel in order to power the Iowa
               | caucus.
               | 
               | Corn farmers could be doing literally anything else,
               | including a whole variety of things that rebuild soil or
               | capture carbon or generate electricity, and it would be
               | equally effective at powering the Iowa caucus, as long as
               | we pay them to do it. They could even be producing crops
               | organically, producing free-range livestock, or producing
               | different lower-return higher-nutrition types of food,
               | should we ever be interested in changing our diet a
               | little. Deciding to produce the world's largest excess
               | food supply in an industrialized fashion and then
               | literally burning it was maybe a poor use of resources.
        
             | rcxdude wrote:
             | We could more or less do that now. In fact we should
             | probably just stop growing corn for biofuel, it's not
             | obvious that it's even energy-positive, let alone a good
             | use of farmland.
        
               | Imustaskforhelp wrote:
               | What do you mean by Biofuel? Like getting it from
               | Biomass.
               | 
               | I don't understand, can't we get Biomass from like
               | undesirable items like (not to gross anyone out, but
               | feces?) whereas corn still has some value where you can
               | actually eat it.
        
             | the_sleaze_ wrote:
             | Yes, and don't forget photovoltaics aren't limited to the
             | crust - they can scale upwards, outwards, on top of oceanic
             | deserts and arid lands.
             | 
             | Cover sunny, bleak northern africa in towering
             | photovoltaics panels baby!
        
               | shermantanktop wrote:
               | Labeling a massive geographic zone in an underdeveloped,
               | historically exploited area--one which plays a key role
               | in how the climate works---as useless, and then
               | converting it to an extractive industry...what could go
               | wrong?
               | 
               | I'm as optimistic as the next person about energy tech,
               | but I hope it doesn't turn out like yet more colonialism.
        
               | linkregister wrote:
               | Yeah, it would be terrible to offer the citizens of Chad,
               | Mali, Tunisia, Libya, etc an opportunity to get revenue.
               | Only Western democracies like Norway and Australia are
               | allowed to extract substances!
        
           | Ygg2 wrote:
           | Grass and trees are pretty bad at converting sun into
           | glucose. Main enzyme in photosynthesis Rubisco is both slow
           | (few molecules per min vs several hundred per second) and
           | lowly selective (confusing O2 for CO2 regularly).
           | 
           | Which makes sense, for most of Earth's geological history CO2
           | was more abudant. So chance of mistaking O2 and CO2 was nil.
           | 
           | https://youtu.be/vYVSH2RpHcQ?feature=shared
        
           | robbiep wrote:
           | Photosynthesis in nature is 1% efficient so it doesn't need
           | to be greatly better to beat it
        
             | otherme123 wrote:
             | The rubisco enzime is specially ineficient. While most
             | enzimes can usually do thousands of reactions per second,
             | rubisco does up to 10. Organisms compensate making loads of
             | copies, to the point it's the most abundant enzime in
             | nature.
        
               | ordu wrote:
               | What can a molecule do for such a long time? I mean they
               | move very fast, the distances there is very short, so I
               | kinda assumed that all the molecules do they do almost
               | instantly. But 0.1 sec doesn't seem like an instant
               | event.
        
           | breakyerself wrote:
           | I wouldn't replace grass or trees with this, but there's
           | places where not much of anything is growing.
        
           | dang wrote:
           | " _Don 't be snarky._"
           | 
           | " _Please don 't post shallow dismissals, especially of other
           | people's work. A good critical comment teaches us
           | something._"
           | 
           | https://news.ycombinator.com/newsguidelines.html
        
         | photochemsyn wrote:
         | After following the literature down several different rabbit
         | holes, I found this argument in some of the supplementary
         | figures on that tree that seems to address your question:
         | 
         | > "Supplementary Note 1 | Advantages of PEC hydrocarbon
         | synthesis.
         | 
         | "In general, PEC systems have the potential to combine the
         | performance of wired PV-electrolysis (PV-E) systems with the
         | simplicity of photocatalytic (PC) systems. PV-E is an
         | established technology, which can take advantage of commercial
         | solar cell modules with light harvesting efficiencies above 20%
         | 24 and state-of-the-art gas diffusion electrolysers operating
         | at high current densities above 1 A cm-2.25 However, PV-E
         | assemblies require additional components including reactors,
         | membranes, pumps, corrosive electrolytes, external cables and
         | control electronics, increasing the overall system complexity
         | and associated cost.26,27"
         | 
         | "On the other hand, PC powders provide an inexpensive
         | alternative to PV-E, since light absorber particles and any
         | necessary catalysts are dispersed in solution, which greatly
         | minimises the overall system complexity. However, wide band
         | gaps and charge recombination often limits solar-to-hydrogen
         | conversion efficiencies to below 1%.28 While a homogeneous
         | dispersion of the light absorber and catalyst can increase
         | reactivity, this also poses challenges for the subsequent
         | separation of all components and products from the reaction
         | mixture."
         | 
         | "Accordingly, PEC artificial leaves provide a balance between
         | PV-E and PC approaches in terms of complexity, cost and
         | performance, by integrating state-of-the-art semiconductors and
         | catalysts into a single compact panel. These PEC devices can
         | perform reactions beyond water splitting (e.g., CO2 reduction
         | to C1 products, or the light-driven C2 hydrocarbon and organic
         | synthesis introduced here), while allowing product separation
         | between the anodic and cathodic sides. This intrinsic design
         | advantage is demonstrated by lightweight PEC systems using
         | 15-fold less material than conventional solar panels, which
         | combine the high performance of wired systems with the high
         | activity per gram of photocatalyst nanoparticles.29 This
         | applicability and potential of PEC-based fuel production also
         | translates to hydrocarbon synthesis. In addition, direct light-
         | driven hydrocarbon synthesis is carbon neutral, avoiding the
         | energy-intensive Fischer-Tropsch process for indirect
         | hydrocarbon synthesis from syngas (H2 + CO)."
         | 
         | Practically speaking the catalysts in these processes have
         | relatively short lifetimes, so you'd want to incorporate an
         | efficient catalyst regeneration process into the production
         | pipeline, i.e. you might only get 16-128 hours of efficient
         | production before catalyst regeneration is required so that
         | needs to be built into any commercial process. So if you can
         | design a catalyst that's easy to regenerate, that's very
         | important.
         | 
         | Source material with nice pictures of the copper nanoflowers:
         | 
         | https://static-content.springer.com/esm/art%3A10.1038%2Fs419...
        
         | japanuspus wrote:
         | Agreed: this is the key question. One effort I follow in this
         | direction is Terraform Industries[0] who are building exactly
         | this type of system.
         | 
         | Their approach is PV + DCC (Direct Carbon Capture) and then
         | simple carbohydrate synthesis, with the goal of establishing
         | standalone autonomous systems that can generate valuable
         | resources on their own in remote areas with ample sunlight.
         | 
         | They have a great blog where they go through their motivation
         | for the approach from first principles [1].
         | 
         | [0]: https://terraformindustries.com/ [1]:
         | https://terraformindustries.wordpress.com/home/
        
         | ErigmolCt wrote:
         | Direct solar-to-chemical systems like this can be more
         | efficient in theory because they cut out the middleman
         | (electricity storage and conversion), but in practice, they're
         | often less mature and have lower overall efficiency right now
         | compared to established solar-electric-chemical setups
        
         | jillesvangurp wrote:
         | Modern solar panels are about 20-25% efficient. Putting it in a
         | battery and using it to drive a car is about 80-90% efficient.
         | Both the battery and motor lose some energy. If you multiply
         | that, you get to about 16-22% efficient (starting with
         | sunlight). And solar panels and batteries are still improving.
         | Perovskite and other multi layer panel technologies provide a
         | path to 35-40% panel efficiency.
         | 
         | Getting a similar efficiency generating some fuel that you then
         | burn at 20% efficiency in a combustion engine results in a net
         | efficiency of about 5%. That might improve on the fuel
         | generation side but electricity generation would improve in a
         | similar way and it would not be as efficient as that
         | (thermodynamic laws and all that). It's basically not going to
         | get much better than being between 4-8x less efficient than
         | battery electric.
         | 
         | BEVs are winning on price and cost for that reason. Batteries
         | are getting dirt cheap (50-60$/kwh). Solar and wind energy
         | basically have no marginal cost. Driving 500K miles at 20
         | gallons/mile costs 75K$ at 3$/gallon for 25K gallons of fuel.
         | 500K miles is a realistic life expectancy for modern battery
         | electric drive trains. Good luck with that with an ICE car.
         | Grid electricity isn't free but it won't cost you 75K. And
         | honestly, you're going to be spending more than that on fuel in
         | most parts of the world. And there's maintenance, parts, oil
         | (engines use a lot of that too), etc. Bottom line: you could
         | buy a new EV for 30-40K, and use the remaining savings for
         | maintenance, tires, etc. All on the money that you aren't
         | spending on fuel. Even a free ICE car would be a bad deal
         | compared to that. You'd lose more money on just the fuel than
         | you save on the car.
         | 
         | Now are efuels going to be cheaper or more expensive than
         | regular fuel? It's a rhetorical question. We all know the
         | answer (no way in hell). Hydrogen, bio fuels, efuels, etc.
         | don't really stand any chance economically. None whatsoever.
         | This is just greenwashing noise. None of that stuff is going to
         | scale or matter. Some of the technology might matter for other
         | purposes though. Hydrogen is super useful for lots of things
         | and providing chemicals that we currently produce from oils
         | synthetically could be valuable too.
        
       | rsoto2 wrote:
       | I'm in my early thirties and I feel like i've heard about an
       | "artificial leaf" every five years for the last fifteen.
       | 
       | We have leaves. Can scientists invent something to help us
       | convince politicians to actually give a shit about saving the
       | planet we depend on.
        
         | Arkhadia wrote:
         | I think the reality is there is no saving anything. Only
         | surviving as long as we can. Why dump billions into an
         | impossible goal of saving when we could invest in survival? I
         | hope I'm wrong but anyone that knows anything about investments
         | knows that there's a point where you need to cut your losses
        
           | doctorwho42 wrote:
           | The system of economics that we use is quite new on the
           | historical scale, using it in your argument to say that
           | saving earth based life (which we are apart of) is not
           | financially viable is the most absurd thing in modern
           | society. Without the ecosphere, the economic system ceases to
           | exist... So by the very definition, it is the utmost
           | important and therefore not only viable but absolutely
           | necessary.
        
             | fc417fc802 wrote:
             | It isn't clear what criteria is being used here for
             | "saving" something. People often use "save the planet" to
             | mean stopping most or all ecological changes. That very
             | well might not be viable in which case survival ie
             | adaptation is the other option.
        
         | incompatible wrote:
         | Many politicians are more interested in protecting the coal,
         | oil, and gas industries. Renewable energy and methods of
         | extracting carbon from the atmosphere are the last things they
         | want.
        
           | teamonkey wrote:
           | Removal of carbon from the atmosphere is exactly what they
           | want, because it gives them justification to sell more oil
           | and gas.
        
         | cyjackx wrote:
         | The pragmatic answer is that it is probably a better spend of
         | time to innovate tech that circumvents politics than to spend
         | time winning politics.
        
           | lukas099 wrote:
           | A lot of the tech research and investment is done by
           | governments, though.
        
           | usrnm wrote:
           | Yeah, because it worked flawlessly the last time we tried
           | (crypto)
        
         | dennis_jeeves2 wrote:
         | >I'm in my early thirties and I feel like i've heard about an
         | "artificial leaf" every five years for the last fifteen.
         | 
         | You have a good memory. Most people don't, so the ruse of
         | living in a world with amazing breakthroughs works really well
         | with most people.
        
         | fred69 wrote:
         | Early seventies here, can extend and confirm your observation.
         | Also flying cars, artificial intelligence, fusion power,
         | equitable wealth distribution, ...
        
         | BurningFrog wrote:
         | Decarbonizing is the biggest political project in the world.
         | Enormous resources are applied to it.
        
       | tcdent wrote:
       | In the next couple years we'll be modifying and creating
       | biological structures that perform these functions.
       | 
       | Building it by mechanically manipulating inert materials feels so
       | 1950s.
        
         | jfengel wrote:
         | Biology is stunningly efficient, but it's hard to optimize
         | further. To get really high yields you usually need industrial
         | processes.
        
           | wffurr wrote:
           | Solar panels are ten times more efficient than
           | photosynthesis.
        
             | joak wrote:
             | Today it's 10x more efficient, but it could theoretical get
             | 100x more efficient, worth working on it.
        
               | tbrownaw wrote:
               | Can it? I thought panels were well over 10% efficiency
               | these days. Plus I'm pretty sure there's a hard limit
               | somewhere below 100%.
        
               | moebrowne wrote:
               | It's called the Shockley-Queisser limit.
               | 
               | https://en.m.wikipedia.org/wiki/Shockley%E2%80%93Queisser
               | _li...
        
           | Layvier wrote:
           | isn't the self replicating property of life a huge benefit
           | though?
        
       | yesbut wrote:
       | How many natural habitats will need to be destroyed in order to
       | make artificial leaves useful in any meaningful way?
        
         | gaiagraphia wrote:
         | I'm pretty glad that when we've chopped down all our forests,
         | we'll have mechanical leaves as a backup plan. Having the means
         | to generate enough electricity to take oxygen out of the
         | atmosphere could be useful.
        
         | joak wrote:
         | Natural habitats has been destroyed by agriculture.
         | 
         | In the US 10-20% of agricultural land is used to produce
         | chemicals like starch, sugar or biofuels, if we could use less
         | land to produce these it would be great.
         | 
         | Photovoltaics could be up 100x more efficient in producing
         | these chemicals.
         | 
         | This technology could free agricultural land back to natural
         | habitats.
        
       | mrbluecoat wrote:
       | > a perovskite and copper-based device that converts carbon
       | dioxide into C2 products - precursory chemicals of innumerable
       | products in our everyday lives, from plastic polymers to jet fuel
       | 
       | Star Trek Replicator?
        
         | gus_massa wrote:
         | The device makes ethane and ethylene, oversimplify it's just
         | natural gas. You must put it inside a huge petrochemical
         | refinery to join some of them to make plastic or fuel.
        
       | krunck wrote:
       | Stuff like this(and fusion) is where we should be putting our
       | research energies.
        
         | aeonik wrote:
         | You don't want another new JavaScript framework instead?
         | 
         | Speaking of which, it feels like we are overdue for the next
         | big one. Is it actually slowing down?
         | 
         | Everybody just went head first into AI?
        
           | VladVladikoff wrote:
           | > Is it actually slowing down?
           | 
           | All I want for Christmas...
        
             | jumperabg wrote:
             | ... is artificial leafs that create liquid fuel for fusion
             | reactors.
        
           | xmprt wrote:
           | Clearly that's what they meant when they said fusion:
           | https://fusionjs.com/
        
           | cookiengineer wrote:
           | Maybe we should make a javascript UI framework generator. Let
           | an LLM build your next hype UI framework in a matter of
           | seconds.
           | 
           | Could be fun with a highscore that is measured by most amount
           | of dependencies and lines of code, the more the better. The
           | prompt is limited in length. Task for the user is to generate
           | the most amount of code with a single prompt.
        
             | mystified5016 wrote:
             | High score based on the size of binary blob you have to
             | send to user's browsers. Bonus points if you max out RAM
             | without crashing the system
        
       | noisebuffer wrote:
       | So can I make a realistic plant mech mobile suit now?
        
       | ErigmolCt wrote:
       | Mimicking photosynthesis at this level, using durable inorganic
       | materials like copper and perovskite, feels like one of those
       | "quiet breakthroughs" that could end up being a game-changer if
       | scaled up
        
         | lukan wrote:
         | In what way? Energy production? I believe there are quite some
         | breakthrougs required for this to compete with cheap solar
         | panels.
        
           | ozim wrote:
           | From the article:
           | 
           |  _Researchers built a perovskite and copper-based device that
           | converts carbon dioxide into C2 products - precursory
           | chemicals of innumerable products in our everyday lives, from
           | plastic polymers to jet fuel._
        
             | 9dev wrote:
             | Converting CO2 on its own seems like a useful thing, don't
             | you think?
        
               | myrmidon wrote:
               | Not necessarily.
               | 
               | The problem is the somewhat low atmospheric CO2
               | concentration; this is why all the "lets just pollute now
               | and remove the CO2 from the atmosphere with some
               | futuristic tech!" approaches are also kinda doomed,
               | because even if you had some workable process that did
               | not cause excessive costs by itself (like this one
               | possibly), you still need to process _millions_ of cubic
               | meters of air, every year, just to compensate for a
               | single (!!) car.
        
               | leereeves wrote:
               | That sounds like a lot, but a million cubic meters is
               | only a cube 100 meters on each side. So it's on the order
               | of the air in a football stadium.
               | 
               | A 1200 CFM home air conditioning system moves roughly 20
               | million cubic meters per year.
        
               | myrmidon wrote:
               | Sure. But thats still very much a lower bound, and it
               | makes a bunch of idealizing assumptions that are
               | hopelessly overoptimistic (assuming your intake gets the
               | full 400ppm of CO2, and you manage to extract all of it
               | in one go).
               | 
               | Even from those numbers, you already get up to a football
               | stadium of processed air per hour for every small town.
               | For a big city, you need to process that football stadium
               | worth of air _every second_.
               | 
               | Building infrastructure of that magnitude is a major
               | commitment, and if most nations can not be arsed to
               | replace a small number of fossil power plants _per
               | country_ , I honestly don't see us building large air
               | processing plants in every single town in a timely manner
               | (that are extremely likely to be less profitable than
               | replacing the power plants).
        
               | themaninthedark wrote:
               | What is the size of these process units?
               | 
               | Can it be coupled with current air processes?
               | 
               | Every house, office building and factory has air handling
               | units.
               | 
               | Factories and other industrial sites also use
               | compressors.
        
               | teamonkey wrote:
               | Right now they're a fantasy so they can be as large or
               | small as your imagination permits.
        
               | gus_massa wrote:
               | It converts CO2 and H2O into ethane and ethylene,
               | oversimplifying the output is natural gas. What do you do
               | with the natural gas?
               | 
               | You can put it in pipes and send it to a central
               | location, but you need pumps and the pipes are a
               | nightmare.
               | 
               | You can store it in a local tank but you need a pump
               | again, and burn it but it release the CO2 again. Using a
               | solar panel and a battery is easier and more efficient.
               | 
               | (Do they need also some water pipes?)
               | 
               | For a distributed production, solar panels are much
               | better.
               | 
               | Pipes and pumps may work in a centralized setup, but I'm
               | still not convinced it's better that biodiesel or
               | ethanol.
               | 
               | Photosynthesis is very inefficient, so there is a lot of
               | room for improvement. But plants are like self building
               | robots and they store the output in grains that are easy
               | to transport.
        
               | alnwlsn wrote:
               | Earth's atmosphere is 5.15x10^18 kg and at atmospheric
               | pressure density is 1.293 kg m-3. The whole thing would
               | be more like 4 billion billion cubic meters. So a billion
               | AC units could have the whole thing cleaned up in just
               | 200 years.
               | 
               | Which would suggest that maybe as much as 0.1% to 1% of
               | earth's atmosphere has ever passed through an air
               | conditioner.
        
               | nancyminusone wrote:
               | This just has me picturing a scene where global warming
               | is solved not by cleaning it up, but by leaving tons of
               | window air conditioners everywhere, troll physics style,
               | "to cool down the outside"
        
               | the_sleaze_ wrote:
               | Psh, that's not reasonable.
               | 
               | Outer space is like really really cold. What we need is a
               | huge heat pump in outer space that pumps the planets heat
               | out into deep space. All we need is a space-elevator
               | style tube and we're good to go!
        
               | lukan wrote:
               | You would need GIANT radiators. Space is cold but there
               | is also allmost no cold material to transfer heat. So
               | even with a space elevator .. not so easy.
        
               | azinman2 wrote:
               | Makes me wonder if ACs should have built in scrubbers. If
               | that was the norm everywhere, you'd have some mild effect
               | going on at scale.
        
               | myrmidon wrote:
               | It would not hurt, but this just makes no (economic)
               | sense currently, and that's not gonna change any time
               | soon.
               | 
               | Right now we don't have _any_ CO2 scrubbing process
               | without significant maintenance or operating costs, so
               | this would add significant cost to all those ACs.
               | Furthermore, the effect is marginal: With emissions of
               | >6 tons of CO2/year/human, you would have to scrub _a
               | lot_ of air ( >10m3/min with cost-free 100% efficiency,
               | which is a pipedream) to compensate (for a single human);
               | running the ACs on full flow all the time might not even
               | be worth it depending on how efficient the scrubbing is
               | and how clean the source of electricity.
               | 
               | You might say scrubbing clean 10m3/min of air for every
               | human sounds kinda feasible, but just compare the
               | realistic cost of such a setup to the options that are
               | currently implemented, and how much popular
               | resistance/feet dragging they already meet (renewables,
               | nuclear power, electrification, CO2 taxation).
               | 
               | As a general benchmark, I would suggest that before the
               | scrubbing technology in question has not managed to be
               | installed at most major stationary _sources_ of CO2 (coal
               | /gas power plants, etc), it is not even worth discussing
               | it for distributed air scrubbing.
        
               | azinman2 wrote:
               | You have to start somewhere. Even a not great solution
               | can set the president, with goals to gradually increase
               | the efficiency. Mandates can do a lot -- just look at the
               | catalytic converter. Put it on all HVAC systems and
               | _something_ will happen even if a small effect given the
               | HVAC itself is contributing way more CO2.
               | 
               | We need all across the board solutions, and if you start
               | requiring small scrubbers to function that can start to
               | provide scale effects that can translate for bigger
               | systems.
        
               | scientator wrote:
               | https://mashable.com/article/ac-units-climate-change-
               | carbon-...
        
               | zdragnar wrote:
               | I was doing to say that surely it's a larger percentage,
               | especially including all the commercial and industrial AC
               | units running non-stop.
               | 
               | Then I remembered that my dad didn't have indoor plumbing
               | in his house for most of his childhood, and that 200
               | years is a much longer time than my first gut instinct.
        
               | reverendsteveii wrote:
               | okay but what's several million cubic meters of air times
               | all the cars operating on earth right now?
        
           | __MatrixMan__ wrote:
           | One thing that cheap solar panels can't do is produce
           | feedstock for a 3d printer. The effective wattage of
           | something that prevents the need to ship something from the
           | other side of the planet could be quite high even if it's
           | actual wattage is low.
           | 
           | That's not to say that we're there yet. Specialists in other
           | countries still make a much better widget than the robot in
           | my closet and they will for a while. But it's a step.
        
         | chr1 wrote:
         | Perovskite is not durable though, and that's the main reason it
         | is still not used in solar cells.
        
       | npodbielski wrote:
       | What is wrong with normal leafs?
        
         | rad_gruchalski wrote:
         | One has a hard time making a ton of money with them.
        
         | pfdietz wrote:
         | They transpire enormous amounts of water.
        
       | breggles wrote:
       | Should we really be making more plastic and carbon fuels?
        
         | once_inc wrote:
         | As always: there is nothing inherently wrong about either
         | plastics or carbon fuels. The problem is in using it in
         | incorrect situations. Plastics are perfect for transporting an
         | preserving foodstuffs in. Cheeses, meats, etc all have
         | significantly longer shelf-lives because they are placed in
         | plastics in a protective atmosphere. It is things like plastic
         | bottle-caps, plastic straws, and other (generally small)
         | disposable plastic tools that find their way into nature and
         | wreak havoc.
         | 
         | Similarly for carbon fuels: these can have extremely high
         | energy density coefficients, and are usable on a global scale.
         | I would still prefer a move away from them and into Nuclear,
         | but for some situations, having a small canister of fuel and a
         | tool to convert that into mechanical action is extremely
         | useful. Chainsaws for instance.
         | 
         | Also: I don't know what the tolerances for this material are,
         | but they might be interesting for use in space?
        
       | init7 wrote:
       | It is quite fascinating to think that leaves are not just a
       | static end product but make further leaves that can again spin
       | off more leaves via many trees in parallel.
       | 
       | Like the algorithm that began billions of years is nowhere done
       | and is expanding. What we build on the other hand crumbles every
       | few years.
        
       | junon wrote:
       | Wow the level of typical HN "if it isn't practical then it's
       | bullshit and not worth doing" sentiment is unusually high today.
        
         | parpfish wrote:
         | Don't forget the classic "let's hyperfixate on any negatives
         | for the new thing instead of comparing them to the negatives of
         | the current solution"
        
       | glitchc wrote:
       | It's great that we can finally turn over a new leaf.
       | 
       | I'll see myself out.
        
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