Scientists Create World’s 1st Practical Artificial Leaf, 10X as Efficient as the Real

[Table 5]

Originally Posted by Young-Sneezy

I'm sure some environmental group will come and complain about how this is disrupting some sort of environmental eco system-something and cry enough until it gets shut down...

What the hell are you talking about?

[To Be Quite Honest]

Originally Posted by HPLovecraft

This is all well and good until the leaf turns on humanity and self-replicates into a hundred-billion-human-civilization-destroying man-eaters.

Or women learn to replicate themselves...

[SebC]

Originally Posted by Table 5

What the hell are you talking about?

Probably something like this:

http://solar.calfinder.com/blog/sola...-power-plants/

Or even the people who oppose nuclear.

[Frank MetaMusil]

I wonder if they feel the same when wiping in the bushes......

[Canada 02]

this is the guy
http://web.mit.edu/chemistry/dgn/www/index.shtml

this is his company
http://www.suncatalytix.com/

here is a recent lecture of his (very long; skip ahead to ~40 min mark for the good stuff)

[Shazam]

I'll beleaf it when I see it.

[To Be Quite Honest]

http://www.suncatalytix.com/

The companies website. Very exciting news. $20.00 for 100watts of electricity according to the video.

[Yasa]

I wish real leaves would be efficient enough to rake themselves in the fall.

[Itse]

Originally Posted by photon

Solar radiation at best is like 400W/sq.m. and we'll ignore the fact that it's much less in the morning or evening.

Actually peak solar insolation levels at the equator (insolation = radiation at ground level) are about 1,000 W/sq.m. You can get very close to this elsewhere (even in Helsinki) by placing a surface directly at the sun.

EDIT: Yearly insolation numbers range from something like 4kWH/day to 6,5 kWh/day. Let's assume developing countries have an average of 5 kWh/day, being typically sunny places. The best currently available commercial panels have efficiencies of something like 25% (or slightly better, they get better fast). Let's assume this system is very efficient, say, 40%. In a playing card size, this would produce 12Wh/day. You could charge a cell phone (my cheap phone has a battery of about 3Wh, and it lasts for almost a week) and put up a couple of smallish LED lights (something like 2-5Wh) for some extra reading time after sunset, assuming you have some power storing abilities.

So, a playing card powering a house? Not complete baloney, but you're assuming a pretty low standard of living. (Though cell phone charging and lighting after sunset are big issues.)

[Itse]

Originally Posted by Canada 02

By the way, this was a really good lecture on energy in the global level, not just the stuff he's into himself. I highly recommend watching it in the whole.

[GreenLantern]

Originally Posted by photon

Um, it's not fuel storage, it creates hydrogen and oxygen which just float away unless you do something else with them.

Interesting if true, unfortunately there's no paper to go along with it.

The next question is how expensive will they be per volume hydrogen or unit electricity generated, because if they take a ton of money to make, it still doesn't help.

[kirant]

All very nice (though the part about powering a developing nation sounds like junk because, as Photon has pointed out, the Laws of Thermodynamics do not make sense with the described values of effectiveness (more on this at the end)), but this also raises multiple issues. First is the ability to capture and separate the gas (which I could imagine would be done by absorbing the oxygen onto something). The second, much more minor, issue that I know of off the top of my head is oxygen pollution. Oxygen at higher concentrations is more deadly (and gives lead to damages from free radicals).

On the topic of thermodynamic failures, let's say it COULD be 100% efficient with energy (IE the energy you put in is the energy you'll get out...an impossibility given the two laws of thermodynamics, as nothing can be =<100% efficient):
- Given Photon's calculations, I get 2.3086 watts of power out of the card sized leaf.
- That means that you can vapourize 8.077*10-6 moles per second, giving you 8.077*10^-6 moles of hydrogen every second. Assuming 24 hour permanoon type of conditions, that gives .697838 moles of hydrogen to work with (as oxygen is pretty useless here).
- The combustion enthalpy of hydrogen is -288 kJ/mol (where the extra energy comes from is the ignition source. Pretend it doesn't matter ), or yields 200977 J of energy.

Given these values: http://www.absak.com/library/power-consumption-table ... (assuming you let these things build you hydrogen all day):
- 2 of them will run an electric clock non-stop (until you need to replace the leaf)
- 205 will keep you food in the fridge
- 2 charging all day will let you watch a short sports game on a 12" black and white TV
- 306 will be needed to let a pair of brothers with a sander and saw build a house on a standard 8 hour day.
- 4 charging all day could give dad his morning cup of joe, toast, and keep him nice and shaved for the work day
- ~2150 will keep a small 5 room apartment cool

While some don't seem too bad, remember that these are assuming permanent lighting conditions AND requires the full day of energy to fuel the short events.

Seems a little impractical still...but I don't mind where it's heading.

[photon]

Originally Posted by Itse

Actually peak solar insolation levels at the equator (insolation = radiation at ground level) are about 1,000 W/sq.m. You can get very close to this elsewhere (even in Helsinki) by placing a surface directly at the sun.

I thought the 1,000 w/sq.m. figure was at the top of the atmosphere?

EDIT: Ah the value I found was an annual average not a peak.

[Kybosh]

Originally Posted by Canada 02

this is the guy
http://web.mit.edu/chemistry/dgn/www/index.shtml

this is his company
http://www.suncatalytix.com/

here is a recent lecture of his (very long; skip ahead to ~40 min mark for the good stuff)

I'm late to the party here but Dan Nocera is a legit researcher. He is a professor at MIT and runs a research group there. His group has been known for doing some outstanding work in a variety of areas. I've had beers with him a couple of times and he is a really cool guy albeit a bit egotistical. One conference I was at, a group of us were having beers with Dan and he pointed at a tree and said. "See that tree? I f###in' own that tree."

All that being said, Dan is one of those salesmen scientists. His lectures often leave you feeling warm and fuzzy but upon reflection you realize that he never really told you much of value (as far as technically useful information goes).

[Thor]

Very interesting video, lots of hope there but wow they have a lot of work to do and setting some very gutsy goals.

I'm sure we're all in the same boat hoping they'll pull this off.

[Shades]

[TheSutterDynasty]

These glorified stories of revolutionary technology are almost always bunk.

Hey look, hydrogen power!!

[TorqueDog]

Too bad these guys are still a private company. This is the sort of company I'd invest in for the long term.

[CampbellsTransgressions]

Originally Posted by TheSutterDynasty

These glorified stories of revolutionary technology are almost always bunk.

Hey look, hydrogen power!!

Am I wrong in thinking that this only made the news because of Fox?

[Itse]

Originally Posted by TheSutterDynasty

These glorified stories of revolutionary technology are almost always bunk.

That's true. However, this is not your typical Fox News -type hype over some garage genius. Just look at the list of people involved, those are some genuine top experts in the field, including major industrial players.

I'm pretty sure they've got large parts of the technology down. Of course that doesn't mean it's going to be all it's promised to be (almost certainly not, because real life is always surpisingly complicated), and it doesn't mean they will get the final technical problems solved to make this a viable technology, but I'm relatively comfortable thinking that this isn't "bunk", meaning "there's no way this is going to work".

Also, there's also a lot of technologies that people were sceptical about but a few years later they're so commonplace nobody even remembers that. For example there was still a lot of scepticism towards touchscreens a decade ago.