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MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

wired.co.uk

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Re: MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

#31

Post by berntb »

puredemo wrote: post #29
berntb wrote: post #20

Earlier quoted context omitted.

>>Solar panels are already good enough that they are used in developed countries such as USA and UK. Are they perfect? No, they cost too much, and they don't generate enough electricity, but they are used none-the-less. Does no one follow energy news, except for oil prices and the Polywell project?! :-) Many estimates talk about soon reaching "grid parity" in large parts of the world. If this leaf isn't good enough,…

Where do you get your energy news from?

I don't really follow it either, just some tech/science news outlets that waste my time by covering [edit: Energy], too... :-)

Re: MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

#32

Post by pbsurf »

Unless this work differs completely from Nocera's previous work, the device relies on a conventional solar cell (with sub 20% efficiency if made from silicon as suggested in the press release) to provide current for electrolysis of water. Nocera's group focuses on developing low-cost, durable catalysts for electrolysis that can work efficiently at neutral pH. This would allow electrical energy (from solar or other sources) to be stored as hydrogen gas.

However, there are other ways to store solar energy once it is converted to electrical energy or chemical energy. The bigger impediment to large scale adoption of solar is the high cost and low efficiency of initially capturing the energy in each photon. Unfortunately, Nocera's interesting work does not address this much greater challenge.

Also, why was the device tested for only 45 hours? It would have taken more than two days just to prepare the talk he gave. This almost certainly means that the efficiency started dropping and the experiment was stopped.

Anyone interested in this topic should check out the work of Michael Gratzel and others on photoelectrochemical cells, which are more deserving of the label "artificial leaf."

Re: MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

#33

Post by VladRussian »

photophotoplasm wrote: post #26

> MIT's artificial leaf is ten times more efficient than the real thing This doesn't surprise me, to be honest. Organisms have evolved to be fit enough to survive, and efficiency above a certain level might not affect an organisms fitness (or might even affect it negatively).

they didn't specify efficiency criteria.

Was it input solar energy to O2 output? to H2 output?

Was it input solar energy to electricity output - trees doesn't directly produce it, so what thermal efficiency coefficient they applied to calculate conversion, if it is the case?

...

Re: MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

#34

Post by thehotdon »

photophotoplasm wrote: post #26

> MIT's artificial leaf is ten times more efficient than the real thing This doesn't surprise me, to be honest. Organisms have evolved to be fit enough to survive, and efficiency above a certain level might not affect an organisms fitness (or might even affect it negatively).

Engineering beats evolution, every time.

Re: MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

#37

Post by photophotoplasm »

thehotdon wrote: post #34
photophotoplasm wrote: post #26

> MIT's artificial leaf is ten times more efficient than the real thing This doesn't surprise me, to be honest. Organisms have evolved to be fit enough to survive, and efficiency above a certain level might not affect an organisms fitness (or might even affect it negatively).

Engineering beats evolution, every time.

Horses for courses, and all that.

Re: MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

#38

Post by bad_user » 

    Provide every house on the planet with an artificial
    leaf and we could satisfy our 14 terrawatt need with 
    just one gallon of water a day.
One gallon of water a day, in case we are talking about freshwater, is waaaay to much.

In case you haven't noticed, there are regions in this world with a freshwater deficiency (precisely those third world countries which would benefit from something like this), and one gallon of water per day is enough for 3, even 4 people to drink per day.

The article doesn't make it clear if this can function with salt-water, which would be more difficult. And if it cannot, this is not bio-friendly or cheap for that matter.

Re: MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

#39

Post by wriq »

bad_user wrote: post #38

Provide every house on the planet with an artificial leaf and we could satisfy our 14 terrawatt need with just one gallon of water a day. One gallon of water a day, in case we are talking about freshwater, is waaaay to much. In case you haven't noticed, there are regions in this world with a freshwater deficiency (precisely those third world countries which would benefit from something like this), and one gallon of w…

The US and other western nations would make up for it quickly. According to http://www.sustainablebusiness.com/index.cfm/go/news.display... we currently use 200 Billion gallons of water per day for the current Coal/Nuclear system. There's around 115 million households in the us so one gallon per house per day would be exponentially better.

Re: MIT's artificial leaf is ten times more efficient than the real thing (Wired UK)

#40

Post by dools »

thehotdon wrote: post #34
photophotoplasm wrote: post #26

> MIT's artificial leaf is ten times more efficient than the real thing This doesn't surprise me, to be honest. Organisms have evolved to be fit enough to survive, and efficiency above a certain level might not affect an organisms fitness (or might even affect it negatively).

Engineering beats evolution, every time.

Except for baby formula vs. breast feeding!
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