Perovskite is not durable though, and that's the main reason it is still not used in solar cells.

In what way? Energy production? I believe there are quite some breakthrougs required for this to compete with cheap solar panels.

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

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/

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...

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.

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?

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.

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.

>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, ...