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Nocera Takes Solar Energy for the Masses One Step Further

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A couple of weeks ago, the social media networks were buzzing over the announcement of new technology that uses sunlight to split water for energy purposes; the so-called "artificial leaf." It’s a man-made form of photosynthesis, a water-splitting technology that could potentially overcome the big challenges facing solar energy, like its current costliness and inability to provide energy when the sun goes down. MIT chemist Daniel Nocera unveiled the new artificial leaf at a recent American Chemical Society annual meeting, but many of the people commenting on it in the press didn't have the opportunity to see the technology in action.

MIT chemist Daniel Nocera recently unveiled technology he calls the "artificial leaf" that uses sunlight to split water into oxygen and hydrogen fuel. Credit: Andre Doreto/flickr.

As a trained chemist, I wanted to reserve judgment until I could see this invention for myself. Lucky for me, this weekend I had the chance. And I have to say it was pretty impressive.

On Saturday, Nocera gave a lecture in Princeton, N.J. (where Climate Central has one of its offices) as part of a symposium honoring the university’s new chemistry building. The symposium was focused on the big problems the chemistry community should be tackling in the years ahead, and it’s not surprising that three talks, including Nocera’s, were directed at making solar energy more affordable and widely available.

Nocera’s presentation in particular was a show-stopper. He demonstrated via video he can already make a bit of sunlight turn a glass of water (containing a small card made of silicon and a few other materials) into hydrogen and oxygen gas. It might not sound like anything too fancy, and it doesn’t look like any leaf I’ve ever seen, but it's being described as the first time that a chemist has found what appears to be an inexpensive way to mimic what plants have naturally been doing for millions of years.

Through photosynthesis, plants convert sunlight into energy (albeit inefficiently) by splitting water up into its constituent parts: oxygen and hydrogen, and then storing these alternative forms of energy until they are needed later on. For humans, the goal is to do the same thing because hydrogen and oxygen can be recombined in a fuel cell to produce electricity whenever you might need it. It may also be possible to take the hydrogen and combine it with carbon dioxide (CO2) to make fuels resembling gasoline, similar to the way plants use the hydrogen to make sugars. 

I should point out here that water-splitting itself is nothing new. It’s actually been around for decades, but most versions haven't used sunlight (instead they have required electricity from the wall to achieve water splitting). Researchers from the Department of Energy's National Renewable Energy Lab found a way to do solar-powered water splitting more than 10 years ago, but the materials in that example were, as Nocera calls them, “space-aged.”

In other words, crazy expensive and not appropriate for widespread use.

Nocera’s set-up, on the other hand, uses much cheaper materials. He hasn’t revealed the exact identity of his new catalysts (which are now being patented), but preliminary versions of his “leaf”, which have been published over the past few years, call on some of the cheapest metals around.

He has said for years that massive expansion of solar power is one of the only ways that the world will be able to meet its growing energy demands in a sustainable way. There are several energy analysts that don’t agree with him, instead saying that other sources of energy, like wind, geothermal and nuclear, must also play a big role.

Nocera’s argument, however, is that most of the new energy demand will be coming from the developing world, where building up solar power for individuals will be a more realistic option than other forms of energy.

“In the U.S., we’re stuck with this ball and chain of legacy energy,” he explained on Saturday. Nocera says that countries like the United States are so heavily invested in existing energy infrastructure that there isn’t much chance the country can easily switch to renewable options like solar. On the other hand, many developing countries completely lack a central electrical grid. People living in many parts of African and India, for example, still rely heavily on the direct combusion of coal, wood, or dung for fuel and don’t have access to electricity.

He says that if solar power technology can be mass-produced on the cheap, there won’t be any reason for developing countries to build massive power plants and thousands of miles of power lines. Instead, each household can have their own energy source. All they will need is a copy of the artificial leaf (albeit one larger than Nocera’s test version) and about 16 ounces of water.

According to Nocera, the volume of water in MIT's Olympic-sized swimming pool contains enough energy to power much of the planet's electricity demands if scientists and engineers can find a way to harvest it efficiently. Credit: Cesar Harada/flickr.

How much water would be needed altogether to power the planet, if an inexpensive version of the technology is manufactured so everyone on Earth can have it? About the same amount as what’s in MIT's Olympic-sized swimming pool, says Nocera. And this volume could be a one-time demand because, in theory, the water would be remade again in the fuel cell. 

Of course, this is all still in ivory tower-territory, and it will be years before a commercial model of Nocera’s setup might be available (and there isn’t any guarantee it ever will be). But the fact that so much energy is stored up in the chemical bonds of water explains why so many chemists think that solar-powered water splitting is such an essential research goal.

At Saturday’s presentation, Nocera didn’t even begin to address exactly how long it will be before his technology, or a similar version of it, could be put to use in the real world. But one day earlier, during an interview with NPR’s Ira Flatow, he said it could be ready in less than a decade:

We're building prototypes, and there's a lot to still do because you need to make sure this can go for years, not days. It's got to go for years. We haven't had the time to test [it] for years yet.

It's been going for days now with no drop in activity. So those are all the practical concerns of long-term because if you're a commercial buyer, you're a customer, you only use things that are reliable, and that can be the death knell of any technology. But we're well beyond the science, and now we're into the engineering and into the reliability game.

To get a sense of what Nocera's talk was like on Saturday, have a look at this PopTech video from 2009. The video was filmed before he made the entire "artificial leaf" but it describes the motivation for water-splitting and also outlines the calculations on how much water is needed to meet the global energy demand (check out the 15-mark in particular).


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By Albert Reingewirtz (19083-5631)
on April 12th, 2011

This sound like the endless machinery that ends up producing the same amount of energy it uses to do what it was manufactured to do. Impossible! I may be wrong since I am not a chemist and do not understand the A, B, C of it.
I have a better idea. Adopt the Chinese solution: One child per couple, no more! If you want more, adopt. Everyday we create more demand of energy, food, waste disposal than we can manage. Humanity is like a biofilm slowly consuming the earth. As usual, historically China has the solution, no Nocera.

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By Dr. Kashinath Nag (Pune, Maharastra, India-411015)
on April 13th, 2011

I am a retired scientist. I had been reading about alternate Energy since 1981. Then, I started concentrating on Energy from Sun to split water to Hydrogen and Oxygen. Read most of the abstracts on this and compiled in the Computer and into my brain.I need to work on it directly under / with someone so that it can be commissioned in the commercial scale. However, we to think how to collect, store,  transport and finally deliver to the actual consumer. May kindly be contacted at my Mail ID. Regards, Kashinath Nag, Pune, India

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By Nathan Burt
on April 13th, 2011

Wow! What a pleasant surprise to see another sensible and usable renewable energy source working it’s way up the chain. I have to tip my hate to this man as the Idea Seems so simple yet it took till now to figure it out. Well done!

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By BIll Christensen (Austin, TX 78737)
on April 13th, 2011

In response to Mr. Reingewirtz: 

I believe the point you’re missing is that there’s a constant input of energy from the sun.  That’s how you avoid the “perpetual motion machine” problem.  It’s not a closed system.

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By Alan L Henderson
on April 14th, 2011

For a chemist the writer seems a little naive. One swimming pool full of water will supply “much of the planet’s energy needs?”.

Really? Ummm…. For how long?

Actually, it’s for 1 second according to Dr Nocera. Not a big deal - there’s plenty of water but a little more scientific rigour in reporting would be nice.

Unless we’re talking cold fusion. smile

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By James Castle (New York, New York 10007)
on April 14th, 2011

This is a response to comments placed by Mr. Reingerwertz: To begin with, at least you excused your innacurate comments on the technology with the admission that: “I may be wrong since I am not a chemist and do not understand the A, B, C of it.”  Yes you are wrong and I respectfully suggest that you get the facts before you make comments. However, your concept that humanity is “like a biofilm consuming the planet”  was really rather accurate.
However,  I submit to you that while the human-race is creating environmental and resource demands on the planet, we are also learning to cope with them. And if we fail to cope with them and innovate and engineer our way out of the energy and resource delemas that we face, I can assure the outcome for humanity will be very dim indeed. But consider this homosapiens - in their present robust form - have existed for about 50,000 years. In that space of time we split the atom, sent men to the moon and mapped the human genome. That my friend is some impressive species of biofilm. The best is yet to come

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By Pat P (Covington/Wa/98042)
on April 29th, 2011

Fossil fuels are energy from the sun. The plants use the suns energy to grow and store energy in leaves. Some leaves collect in areas that are covered up with mud and over ages are transformed into coal, oil and natural gases. We pull that out of the ground and process it into a fuel that we can burn.
Dr Nocera’s process uses the same original input (sunlight) and turns it into a fuel we can burn. It changes the entire paradym of how we get energy. Energy is the largest segment of the worlds economy and this invention has the capabilty of eliminating to the whole current structure.
Eventualy you can imagine unpluging your electric and gas meter and pluging in Dr Nocera’s device. Complete independence from the entire energy infrastructure.

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By Samuel Puletasi (Pago Pago/AS/96799)
on August 2nd, 2011

I am confident that Nocera’s discovery will succeed and it won’t take more than 10 yrs to be out in the market.  Just a thought that water that use to produce electricity will slowly diminish as it reuses.  Secondly, there will be a miniature version for cars so it won’t depend on homes for refuling.

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By jhon (Sherman oaks, CA 91423)
on April 7th, 2012

Great article and right to the point. I am not sure if this is actually the best place to ask but do you people have any thoughts on where to get some professional writers? Thanks

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By Daniel Jacobs (Narvon/PA/17555)
on November 13th, 2012

The trick is to entice a business model that will attract enough attention to keep those who may suppress the technology. Not trying to sound too conspiratorial but since John Rockafellow the industry has actively fought for their carbon monopoly. Can a manufactor go up against the carbon-money long enough to make a profit?
I think there is alot of evidence that an electric car is the most efficient future for individualized transportation, with about 75% efficiency. The leaf membrane, combined with fuel cells,  as on-board emergency generators, would make a nice clean model. Be nice to see it in a few years!

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