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Using Sun's Energy to Split Water Means Solar Power All Night
phorm writes "Reuters is carrying an article about a recent MIT development which may pave the way for solar-energy to be collected for use in low-input periods. According to Reuters, the discovery of the a new catalyst for separating hydrogen+oxygen from water requires only 10% of the electricity of current methods. This would allow storage-cells to function as a form of battery for other forms of energy-collection, such as solar panels. The new method is also much safer (and likely environmentally friendly) than current methods, which require the use of a dangerously caustic environment, and specialized storage containers." sanjosanjo points out coverage of the process at EE Times, which features the MIT group's press release.
There is the slight question of where and how you store your hydrogen and oxygen in the meantime so, especially for small scale "localized" applications.
Lets say your house needs 5000 W. To get through an 8 h dark period, you need 40 kWhr, or 136,000 BTU. That's roughly the energy in 2 lbs of hydrogen. To store that much hydrogen, you either need a balloon of 11 m^3 size, or you need a compressor that allows you to store the hydrogen as compressed gas (what costs energy to do) or to liquefy the hydrogen (what costs even more energy). Alternatively you can adsorb the hydrogen into certain alloys, but then you need to heat them to get the hydrogen back out, again ruining your energy balance, and driving up the cost.
This development can help with the development of a large scale hydrogen infrastructure, but there we're better of with natural gas (of which we're not running out anytime soon, and which has much less technological hurdles in storage).
I'm aging rapidly, I bought a new game and had no idea if my machine was good for it.
My experience is that when you try to use electrolysis on salt water you get NaOH and chlorine.
a,e,i,o,u and sometimes w and y (at be if of up cwm by)
50 years ago was 1958. Interestingly enough., that was the year the first solar panels went to space. Today, you can sit right there in your chair, do some googling, whip out your credit card and have dandy solar panels shipped right to your house at less than NASA cost plus pricing levels. That's pretty significant. A few years previous to that, some of the first ones were running $1,785 dollars per watt, and those are unadjusted dollars. Today you can look for deals and get them at around 5 bucks a watt. Not too shabby. And nanosolar started shipping this year, albeit all of it to Germany where demand is higher and they will pay a bit more now, because they know conventional will be going up fast later, so they did a whole nation push for it starting some years ago. That and it is cleaner.
here's the wiki ref for the figures, Solar timeline
I bought mine at actually a little under 5 bucks a watt some years ago. silicon demand has been going more for throw away gadgets and so on in the meantime, but several new fabs go online this year and next year so prices will be dropping again.
For one, professors have to get grants to do their research, so they are sometimes given to overstatement to that end. They are, after all, only human which means that not all of them are honest. Also, some are simply unrealistic. They think they can do something, so they announce it, even though they have no idea how to get there, and then maybe never end up doing so. Finally sometimes shit just ends up being impossible. It looks good, seems like things will work, however in the end you can't make it happen. That happens with research. You can spend millions only to realise you've been down a dead end and there's nothing to be done about it.
I agree an announcement from a major university is much more credible than some startup, but don't think things out of universities aren't overstated at times.
15 amps? 120 watts?
No, most houses have 100-200 amp service. At 120 volts. Which works out to 12000-24000 watts, peak. Average electricity consumption is right around 1 kilowatt, so the poster who said to divide by 5 was right.
Apparently, it must be against the law to use any surface but the car's to generate its solar energy! ; ) A typical garage (22' x 22') with a south facing shed style roof is approximately 54 square meters. Plugging that into your formula gives 40500 watt/hrs produced, nearly 10X what your formula says is needed. The only thing holding it back is the storage capability of the car. With suitable storage we can do this now! BTW, insulation refers to the slowing down of heat transfer. The word representing the amount of solar radiation on a surface is insolation. Otherwise, thanks for attempting to quantify the subject, most people (on both sides) just go off half cocked.
Dan Nocera is one of the top ten names (American, anyway) in this field right now, and he has been working on this with several of the others (such as Jay Winkler and Harry Gray). I've sat through probably 10 of his seminars at American Chemical Society conferences in the last two years, and he was pretty close in April (and seemed really excited about a new development, too). My guess is that he's spent the intervening time repeating the experiments, to guarantee it works. And as to corroborating sources, I'm sure that his cohorts from CalTech, etc. are double-checking everything, too.
Anyway, I guess where I was going with this is that this isn't some fuel pill, or Al Gore rambling on about things he doesn't understand. Nocera is to water splitting what Miyamoto is to video games, and if he says that he's done it, I'm sure he's done it.
My sister opened a computer store in Hawaii. She sells C shells by the seashore.
Indeed, Nocera has been working on this for what must be at least 15 years by now. I remember he had some catalysts four or five years ago that worked using only the ambient intensity of sunlight, but were far too expensive to be practical (so I heard).
I also work in catalysis, and one of my friends is doing water splitting, so I've read a few papers on the topic. The materials used don't surprise me, cobalt is approximately as good as you can find. Also, I would note that this catalyst (I downloaded the paper) is releasing oxygen and gradually producing HPO4, which can then later be oxidized to (presumably) release energy. I'm not familiar with using phosphoric acid as a fuel, but the paper sounds extremely plausible.
I would also suggest that, based on my reading of the paper, any real world applications would be 5-15 years away, depending on how well they're able to coat their electrodes.
The paper is published in a peer reviewed journal. It's patented, not secret.
They used ITO glass as an electrode with a neutral KPi electrolyte with 0.5mM Co^{2+} at 1.29V. They tried it with CoSO4, Co(NO3)2, and Co(OTf)2 as the cobalt source. It also works on FTO glass, as well as with a NaPi electrolyte.
The description of the processing method is extremely detailed. I would have little difficulty duplicating this experiment. (YIAAS)
It's rather snotty to flatly contradict a statement you disagree with, and then claim to have "fixed" it.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
The Cobasys example is bullshit. I admire your integrity in agreeing that it's a bullshit example, by citing the fact that they are used in hybrids (although you also lie about them only being in RAV4 EVs), but am puzzled at your inability to reconcile that fact with your lie about it being supressed. So they don't want to sell piddly quantities to shadetree mechanics. So what. They ARE selling to automakers, while you claim they aren't.
Try again.
But these claims really aren't as extraordinary as you might think. They've found a new catalyst that reduces the amount of energy required to split water. That's what catalysts do--they reduce the activation energy of a reaction. Life would not function without catalysts. Every enzyme in your body (there are thousands of them) is a catalyst designed to make some reaction run efficiently at body temperature.
Every few years a breakthrough catalyst is discovered that makes new reactions feasible. See for example the Grubbs' catalyst which when discovered had almost magical properties compared to the state of the art. Grubbs recently won a Nobel prize for this work.
Currently, platinum is a catalyst on the cathode, for generating hydrogen. This works well and has been known for a long time. This new research has found a useful catalyst for the anode, which generates the oxygen.
While this might be a major breakthrough, I don't find it to be extraordinary, at least in the same sense that a self-sustained cold fusion reaction is extraordinary. These results should be easy to duplicate in other labs as the materials are straightforward.