'Major discovery' from MIT primed to unleash solar revolution

No it doesn't, sunlight has nothing to do with it (using light to lyse (photolyse?) water would be cool, but they aren't). But thank you for the link, it makes more sense then the other one.

In short: as far as I can tell this invention is a new catalyst for increasing the efficiency of electrolysis.

But the catalyst is not better than current ones, it's just less toxic (and therefor cheaper). Which, while helpful, is far from groundbreaking.

The electricity can come from anywhere. Saying solar is just a buzzword to get people to click.

You are correct about your first point - the connection with photosynthesis is shaky at best. This research describes a new electrocatalyst for the production of oxygen. The source of electrical energy for driving this production could be solar cells, but that would be just one potential use.

The paper does focus on photosynthesis, however, because the Nocera's lab works on "artificial photosynthesis," a field largely devoted to understanding the electrochemical processes of photosynthesis and mimicking them in man-made systems. For the most part, "artificial photosynthesis" focuses not on carbon fixation but on the transformation of light to electrochemical energy (via electron/proton transfer). This is the process that Nocera's research is replicating, and likely why he focuses on using solar cells as the source of energy, to parallel a plant's use of solar energy as a route to energy storage/O2 production.

Finally, I think some of your scientific analysis needs correction:

Electrolysis (in its simplest form) doesn't require any solute - it can be performed, very slowly, in pure water. Adding salt (say, NaCl), as you mention, speeds up the rate greatly. However, in doing so, the reaction changes - you'll evolve hydrogen as before, but at the anode you'll evolve chlorine gas, not oxygen. You can't use electrolysis alone to produce oxygen gas or as a route to storing energy. One alternative to this is to use an electrocatalyst, but currently, (as the article mentions), the only available catalysts require expensive metals or very basic environments (or both). This article is on the discovery of a new catalyst that will allow for the production of oxygen via catalyzed electrolysis at neutral pH and with a cheap, abundant catalyst (cobalt).

Also, if we're looking at the same quote: "storing energy for use when the sun doesn't shine," the article is talking about humans storing energy, not plants. Even so, plants do store energy for when the sun doesn't shine. They metabolize hydrocarbons into ATP via mitochondria, just like we do - so glucose and other products of photosynthesis are indeed forms of stored energy.

I think a lot of the confusion stems from the fact that we're reading a popular article and not the actual research - these articles tend to pick up on terms like artificial photosynthesis, energy production, and solar energy and run with them.

Also, the economics work because the demand for power (to pump) is much lower at night than during the day. So that they aren't eating into their customer's electricity consumption.

Thanks for the clarifications.

>artificial photosynthesis" focuses not on carbon fixation but on the transformation of light to electrochemical energy (via electron/proton transfer).

Then why call it photosynthesis? It's not, it's photovoltaics. If you want photosynthesis you have have to fix carbon, or you're making a mockery of the term. And if you are making hydrogen directly, then call it photolysing.

Either way you are not synthesizing anything.

I didn't realize that chlorine is preferred to O2, but what does it matter? I don't want O2, I want H2, and once all the chlorine is gone, won't the sodium hydroxide work just as well as NaCl? Or is that what you mean by 'very basic environment'?

They should rewrite that article and omit any mention of solar, just say they invented a new cheaper way to electrolyze water. Applications include storing energy from solar or wind for when the sun isn't shining.

Doesn't the above paragraph make a lot more sense than the parent article?

In http://www.eetimes.com/news/latest/showArticle.jhtml?article..., the economics and the efficiency of this process are described: "In fact, with our catalyst almost 100 percent of the current used for electrolysis goes into making oxygen and hydrogen." This is definitely more efficient than the existing electrolysis, as the theoretical maximum efficiency of current electrolysis process is about 80%-94% (http://en.wikipedia.org/wiki/Electrolysis).

I'm not sure what you mean by whether it's more efficient than charging and discharging a battery. But the lifespan of a fuel cell is potentially indefinite and it does not require recharge(add in Oxygen and H+ any time and electricity starts to flow). Further, with each battery cycle, the efficiency of a dry cell decreases.

I think this electrolysis process can definitely make a cheaper form of energy storage than, say, batteries. Even though each anode requires small amount of Platinum, but considering the long lifespan of fuel cell storage, this form of energy storage costs much less than traditional batteries in the long run (all the toxic disposal!) And even for the purposes of propulsion, fuel cell discharge is much more efficient than internal combustion engines.