Scientists Develop Artificial Leaf, Uses Sunlight to Produce Valuable Chemicals | Hacker News Reader

Scientists Develop Artificial Leaf, Uses Sunlight to Produce Valuable Chemicals

newscenter.lbl.gov

290 pointsgnabgib120 comments

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?

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.

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.

I roll my eyes at these "artificial leaf" claims for just the reason you've identified.

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.

Aside from the hail, none of those are maintenance requirements. I've done 0 maintenance on my panels over their lifespan.

'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.

To be fair your windows are less likely to take the full brunt of an extra large hailstone since they're usually mounted vertically.

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.

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.

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.

Sadly our solar panels don't self heal or come with 100(0) years warranty.

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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.

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.

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.

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.

> 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.)

Promises of “green hydrogen” and fertiliser made sustainably haven’t panned out. I’ll believe them when I see it, but I’m not a believer in industrial farming, which is more akin to mining.

Green hydrogen can't compete when natural gas-derived hydrogen is allowed to dump its waste CO2 into the atmosphere. That doesn't mean it can't or won't work when natural gas is outlawed. Your evidence shows nothing except that CO2 isn't being controlled.

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.

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.

It is a given that bovines should be eating grass (one of the most productive plants there is with the highest calories per acre), not grain, and with the bonus that bovines or other ruminants eating grass improve the soil ecology and lessen erosion. There also isn’t any need for fertiliser inputs, or any oil/gas produced inputs at all.

Chickens can also be raised more sustainably. They don’t need to be raised 50,000 at a time, and don’t need to be fed grain. I don’t feed mine other than in winter when there is snow, and they don’t forage past an acre or so area. We produce a surplus of more chicken meat and eggs than my household can eat, and I still have enough time to work full time doing something else. (The same goes for my cows, but they take even less work and basically sustain themselves - I have not bought feed for them in two years.)

Oddly enough, I now sell my eggs for less than grocery stores charge for them. I could easily plant enough cereals and legumes for my household (about a 10,000 sq ft area or ¼ acre), but haven’t done this the last 2 years since I put my effort into vegetable gardens and livestock instead.

Part of the big myth is that we need industrial scale “farming”. We don’t. A lot more humans need to be a lot closer to producing the food they eat, though. If someone owns/maintains a lawn, they should be using it to grow food, instead of buying factory farmed food. (I give apartment dwellers a free pass, but I see large swathes of land that do nothing but grow grass and then have a lawn mower run across them.)

We absolutely need industrial scale farming, even if we take 40 million acres of suburban lawns and convert 10 million to active garden rows (there are many constraints on spacing, I'm dealing with this right now). Because 10 million acres feeds vegetable calories to something in the vicinity of 3-30 million people, at very high labor and logistics costs, for a small portion of the year.

It doesn't have to be 99% industrial scale farming in the current format, is the thing.

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.

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).

I'm just picturing whole new swathes of rainforest being clearcut and bulldozed to make way for "artificial leaf farms."

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.

Does it mention it’s 100x more efficient anywhere? Or is it just an example you’re providing, in which case, why not 1000x?

> why not 1000x?

now we're talking - can I invest in your company?

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.

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.

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.

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.

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.

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.

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!

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.

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!

> as useless

It's not useless, it's arid.

> which plays a key role in how the climate works

As does ever other square meter on Earth, and its natural abundant resource could be leveraged to even greater overall good.

> Extractive industry ... like yet more colonialism.

I'm not sure how we got here, or what your actual concern is.

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

Photosynthesis in nature is 1% efficient so it doesn’t need to be greatly better to beat it

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.

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.

I wouldn't replace grass or trees with this, but there's places where not much of anything is growing.

"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

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...

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/

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.

> 20 gallons/mile

I did a double take here, I believe you mean miles per gallon?

> 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.

Disagree, you seem to only be considering cars. All of these things are just different forms of energy storage and they are useful if battery technology doesn’t have multiple orders of magnitude of improvement left in it.

There are numerous high impact use cases where you need more density, faster energy transfer, and completely different weight profiles than batteries.

obviously, nice catch

Stuff like this(and fusion) is where we should be putting our research energies.

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?

> Is it actually slowing down?

All I want for Christmas…

... is artificial leafs that create liquid fuel for fusion reactors.

Clearly that's what they meant when they said fusion: https://fusionjs.com/

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.

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

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.

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

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.

Physics places no such honorific obligation on the species.

This just smacks of self serving “don’t end society I rely on” existential dread. While that booj materialism acts with indifference to externalities.

If the ramifications of there being no immutable force obliging us to preserve each other spread, omg. Then we roleplay out the reality daily with the lack of empathy driving us to the streets 24/7 until better healthcare legislation is passed.

As a culture we rhetorically make such high minded sounding rhetoric then equivocate away doing the work to live up to it. Got trite philosophy to post online don’t you know.

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.

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.

Removal of carbon from the atmosphere is exactly what they want, because it gives them justification to sell more oil and gas.

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.

A lot of the tech research and investment is done by governments, though.

Yeah, because it worked flawlessly the last time we tried (crypto)

>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.

Early seventies here, can extend and confirm your observation. Also flying cars, artificial intelligence, fusion power, equitable wealth distribution, ...

Decarbonizing is the biggest political project in the world. Enormous resources are applied to it.

Late comment on this: saw a short talk by Dr. Eisele at a regional APS conference a few weeks ago on some research aimed at a future non-silicon based solar panels that are easy and cheap to manufacture but also do not lose efficiency at higher temps (as is common with current panels)* Her group apparently is at patent stage on some newer, follow-on research.

ref: https://www.nature.com/articles/s41557-020-00563-4

*that's all from memory, hopefully didn't misrepresent anything

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.

It's great that we can finally turn over a new leaf.

I'll see myself out.

So can I make a realistic plant mech mobile suit now?

Should we really be making more plastic and carbon fuels?

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?

I thought we were supposed to be going no lead.

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.

Biology is stunningly efficient, but it's hard to optimize further. To get really high yields you usually need industrial processes.

Solar panels are ten times more efficient than photosynthesis.

Today it's 10x more efficient, but it could theoretical get 100x more efficient, worth working on it.

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%.

It's called the Shockley–Queisser limit.

https://en.m.wikipedia.org/wiki/Shockley%E2%80%93Queisser_li...

isn't the self replicating property of life a huge benefit though?

What is wrong with normal leafs?

One has a hard time making a ton of money with them.

They transpire enormous amounts of water.

Wow the level of typical HN "if it isn't practical then it's bullshit and not worth doing" sentiment is unusually high today.

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”

> 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?

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.

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