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'Major discovery' from MIT primed to unleash solar revolution

web.mit.edu

11–20 of 35 posts

Re: 'Major discovery' from MIT primed to unleash solar revolution

#12
post #5
post #4

Decentralization of energy production will be revolutionary. This particular article, on the other hand, makes no mention of the economic factors involved in the said processes. To top it off, there's been a sway of "amazing solar discoveries" recently and we'd be lucky to see a handful of them actually make it into the real world. That said, I'll believe it when I see it.

Regarding economics factors: Requiring nothing but abundant, non-toxic natural materials, this discovery could unlock the most potent, carbon-free energy source of all: the sun. Now we can split the water (H2 + O2) in a cheap efficient and highly manufacturing way http://www.sciencemag.org/cgi/content/full/sci;1162018/DC2 Though It requires Platinum at the moment (Pt is not a cheap earth-abundant material).

In the podcast (http://www.sciencemag.org/cgi/content/full/sci;1162018/DC2) Nocera explains the process perfectly. This "missing link" in electolysis has been the production of O2. Now this is possible. And now a closed loop of water splitting and water production is possible for the first time apparently. So, this could indeed be a possible way to store energy for times when there is no sun or wind available to produce electricity. Nocera also mentions that there are already alternatives for Pt for the hydrogen production and they are going to test them.

However, indeed nothing is said on the efficiency of the whole process and thus the economics of this process. How large a system do you need for a household and what would it cost? Hopefully we will get answers soon.

Still you need photovoltaic cells or windmills to produce electricity for your house, your car, etc. And you need extra electricity to produce H2 and O2 for times when there is no sun or wind. PV cells still cost a lot and still are not efficient enough (thus take up too much space). So, there are still other missing links to solve to really start a electricity revolution.

Re: 'Major discovery' from MIT primed to unleash solar revolution

#13

Earlier quoted context omitted.

Although they would require very small amounts (I think). I am pretty sure catalytic converters in cars and other industrial devices use tiny amounts of Pt, and they aren't a real cost burden.

Actually, catalytic converters are pretty expensive, and their theft is on the rise. I know someone who had his car stolen in Oakland. The police found the car, but the catalytic converter was sawed off. Supposedly they run a couple hundred $ minimum. * http://www.nytimes.com/2008/03/29/us/29converters.html

Would like to read that article, but its probably a few bits of anecdotal evidence spun into a trend and story. Also I am lazy and forgot my NYT password.

Re: 'Major discovery' from MIT primed to unleash solar revolution

#14
post #10

According to wikipedia, electrolysis is currently around 65% efficient, with a theoretical cap somewhere around 90%. So this could help, but it's not going to be an order of magnitude improvement. Also, storing large quantities of (I assume pressurized) gas has got to be expensive. The nice thing about liquids is that you can store them in a vat, or a dammed up canyon. I didn't rtfa, its probably cool tech, but hardl…

That was my question too. I had always thought electrolysis was a non starter for large scale production because of the inefficiencies involved.

Even th article seems to focus on how they invented non-toxic catalysts. It mentions nothing about improving the efficiency of the reaction.

Re: 'Major discovery' from MIT primed to unleash solar revolution

#15
post #12
post #5

Earlier quoted context omitted.

Regarding economics factors: Requiring nothing but abundant, non-toxic natural materials, this discovery could unlock the most potent, carbon-free energy source of all: the sun. Now we can split the water (H2 + O2) in a cheap efficient and highly manufacturing way http://www.sciencemag.org/cgi/content/full/sci;1162018/DC2 Though It requires Platinum at the moment (Pt is not a cheap earth-abundant material).

In the podcast ( http://www.sciencemag.org/cgi/content/full/sci;1162018/DC2 ) Nocera explains the process perfectly. This "missing link" in electolysis has been the production of O2. Now this is possible. And now a closed loop of water splitting and water production is possible for the first time apparently. So, this could indeed be a possible way to store energy for times when there is no sun or wind available to pr…

Hu? electolysis makes O2 just fine.

Re: 'Major discovery' from MIT primed to unleash solar revolution

#16

What's not clear to me from the article is, if the cheap easy catalyst makes oxygen gas from water, what's left over before we get the platinum involved, perhaps a bunch of hydrogen ions in solution? Something like 6xH20 -> O2 + 2xH30 or 2xH20 -> O2 + 2H+

What? You can't make oxygen gas and hydrogen ions at the same time. If you make oxygen gas you also make hydrogen gas. Which is not a big deal, electrolysis is not new.

Not sure what the platinum has to do with it though.

Re: 'Major discovery' from MIT primed to unleash solar revolution

#17
OK, I tried. I really tried to give them the benefit of the doubt - I mean it's mit.edu, but seriously what they wrote there and what I know of physics have little to do with one another.

I fell like I'm missing a joke somewhere.

First off: what does electrolysis have to do with photosynthesis? If you want to store energy it's just as important with wind, or any other.

Second: photosynthesis and photovoltaics are not the same thing. They seem to confuse them quite a bit. And on top of that, this seems to have nothing to do with either of them - it's all about electrolysis.

Third: "Currently available electrolyzers, which split water with electricity and are often used industrially, are not suited for artificial photosynthesis because they are very expensive and require a highly basic (non-benign) environment that has little to do with the conditions under which photosynthesis operates."

Has so many errors I don't even know where to start.

a: electrolysis does not require a basic environment, it requires a salty one.

b: again mixing up photosynthesis and photovoltaics

c: there is no such a thing as artificial photosynthesis. Only plants know how to make hydrocarbons from water CO2 and light.

If someone actually did manage to create artificial photosynthesis that would be massive. Which is what I hoped to read about here, and then I didn't.

Fourth: they start off saying something about advances in solar power, and well? Where was the advance? All I see is something about electrolysis.

Fifth: "[plants] storing energy for use when the sun doesn't shine." Most plants don't actually do that. They don't store energy, they make hydrocarbons, which are not an energy source for them, they are the final product. (For us the hydrocarbon is energy storage.) There is the CAM photosynthesis cycle used by pineapples, which does actually store energy for later. But the only reason the pineapple does that is so that it doesn't dry out during the hot day, so rather it collects it's CO2 at night. This does not seem to apply here.

Someone: please tell me if I missed something massive, but this really looks like the kind of nonsense energy inventions you read about all the time. But, but, but it's on mit.edu!

Re: 'Major discovery' from MIT primed to unleash solar revolution

#18
post #17

OK, I tried. I really tried to give them the benefit of the doubt - I mean it's mit.edu, but seriously what they wrote there and what I know of physics have little to do with one another. I fell like I'm missing a joke somewhere. First off: what does electrolysis have to do with photosynthesis? If you want to store energy it's just as important with wind, or any other. Second: photosynthesis and photovoltaics are not…

I'm not qualified (or willing to try and process all the information right now) to say if the claims in the press release are valid, but keep in mind it was written by an HR person, not a scientist or an engineer.

Unfortunately, there's no mention of a publication for this discovery, but you can read about their pior work on their webpage: http://web.mit.edu/chemistry/dgn/www/

Re: 'Major discovery' from MIT primed to unleash solar revolution

#19
The desire to store generated energy for use at a different time isn't limited to solar cells or other day-only sources. A similar problem is posed by the fact that conventional power stations have a fixed maximum throughput, but demand is much higher during the day.

To balance the load and maximize revenue, a number of power producers employ a decidedly low-tech way to store energy: every night, they pump a lake of water up a mountain, and during the day they drain it through hydroelectric generators.

Really! I shit you not: http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

Re: 'Major discovery' from MIT primed to unleash solar revolution

#20
Anyone notice after a couple years of reading digg, reddit, hacker news, even CNN, that these breakthroughs we are continually excited about don't seem to go anywhere? I know things take time time, but I keep waiting for just one of these breakthroughs to make it to the real world, and I can't think of any so far where I read about it, and now it is here.
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