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Wednesday, May 09, 2007 Supplying the World's Energy Needs with Light and WaterContinued from page 1 By Kevin Bullis
TR: And you've had some success putting what you've learned to use. DN: We did make a compound that makes hydrogen using light. We have something that you can dissolve in solution, shine light on it, and hydrogen comes bubbling up. It didn't do it that efficiently. But it was a big advance because it had a lot of new concepts in there to show how you can use sunlight to make hydrogen. TR: What are some of the research problems you're addressing that you hope can lead to a big step forward in solar? DN: Something we've really been working hard at is [understanding] the design principles that photosynthesis operates off. One is that when [photosynthesis] splits water into hydrogen and oxygen, it uses more than one electron. This current that's running is going one electron at a time. But then [the plant] stores them and uses four electrons at once. We don't know how to do multi-electron reactions very well. We don't even have theories to describe them. And then you have to manage protons--and that's what biology does really well. It takes electrical current and then it converts it to a chemical current, and the thing conducting the chemical current is protons. And then it sends atoms. What a photovoltaic does is send electrons to a point. Photosynthesis actually sends not an electron but an atom. And that's even a tougher thing to do because atoms are so much heavier than electrons. So we've gotten down deep into understanding, how do you move atoms [such as hydrogen atoms] around from point A to B so that they can join up with each other? How do you assemble them so they can unite? TR: You've written that chemistry "will likely play the most central role of all the sciences" in addressing energy problems. How would you summarize the role of chemistry? DN: For game changers, it's really easy. There's three. Make photovoltaics cheap, which is a lot of chemistry. It's inventing new materials to make PV cheap. Replace noble metals--things like platinum--with abundant metals. Because there's not enough stuff. When you're talking about this much scale, you better be using things like iron and manganese. You better look at your book that says what are the most abundant elements on the face of the earth. TR: And this is for fuel cells, and also for photovoltaics. DN: Photovoltaics--everything. That's the real technology issue that you have to keep in your mind. Not something that's so great, it's 100 percent efficient--and oh, by the way, I'm using ruthenium. I can use ruthenium now to teach me a principle, but ruthenium's below iron [on the periodic table]. So I better figure out, how can I take everything I'm learning with ruthenium and apply it to iron? TR: And the third game changer? DN: Split water with light. You do those three things, and you have a full new energy economy. It's hard for me to say exactly what that technology will look like, because the science is missing. But at the beginning of the 1900s, we built an entire society based on a new energy system. And I believe, once solar is in place, with help from biofuel, with a little help from wind, we will invent our society again from a new energy source. |
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Solar-Power Breakthrough
07/31/2008
Comments
mkogrady on 05/09/2007 at 1:24 PM
92
garygromet on 05/09/2007 at 1:38 PM
8
Nanomaterials Research Centre at Massey University in New Zealand has developed synthetic dyes that can be used to generate electricity at one tenth of the cost of current silicon-based solar panels.
zippo on 05/09/2007 at 9:29 PM
24
garygromet on 05/14/2007 at 12:44 PM
8
http://masseynews.massey.ac.nz/2007/Press_Releases/04-04-07.html
Massey University’s Nanomaterials Research Centre (Dr Wayne Campbell) generates electricity from sunlight at a tenth of the cost of current silicon-based photo-electric solar cells.
Dr Campbell says that unlike the silicon-based solar cells currently on the market, the 10x10cm green demonstration cells generate enough electricity to run a small fan in low-light conditions – making them ideal for cloudy weather. The dyes can also be incorporated into tinted windows that trap to generate electricity.
nekote on 05/09/2007 at 2:11 PM
115
http://www.greenandgoldenergy.com.au/Documents/SolarEnergyTheOnlyGameinTown.pdf
nekote on 05/09/2007 at 2:27 PM
115
Which are even denser stores of energy?
Specifically, algae.
One of the bio-energy areas currently being actively explored.
The hope is that successful algae farms would be able to produce (at least?) 5,000 gallons of oil per Acre per year - an order of magnitude greater than conventional agricultural crops, such as palm oil and rapeseed.
According to:
http://oakhavenpc.org/cultivating_algae.htm
nekote on 05/09/2007 at 2:40 PM
115
That's a possible research result, before or after figuring out how to get sunlight to split water - setp 1 - isolating / filtering the water molecules.
Of course, there's the two for one win - win.
Energy and fresh water from recombining the split H2 and O2.
mshelef on 05/09/2007 at 4:12 PM
1
I have spent my whole career in a decidedly unglamorous task of catalytically cleaning up automotive exhaust where the catalytic active sites are (and always were) the scarce and expensive platinum group metals. While base metals serve as important catalysts for a host of indispensable products (nitrogen fixation being the most vital one, perhaps), for some tasks in refinery processes, pollution control, fuel cells, etc., the noble metals have proven to be irreplaceable notwithstanding more than half a century of continuous efforts and numbingly recurring claims.
About four decades ago the Nobel winner, Willard Libby, claimed that base metal perovskites performed as well as noble metals in automotive pollution control.
The august (at the time) Bell Labs seemingly confirmed the claim. It turned out to be a mirage associated with rather prosaic Pt impurities in the synthesized perovskites.
Since then until now we are still without “poor man’s platinum”, or ruthenium I might add.
One more remark: in the same time frame (25 years ago?) I fuzzily recall a meeting at Caltech where Harry Gray in a beautiful lecture on photochemical production of hydrogen using homogeneous catalysis by Ru-complexes in water, waved a test tube with a few cc of hydrogen in it. He announced-here it is, but do you realize how much grant money did it cost? Did we make giant strides since to be able to have even a glimmer of hope that it might make a dent in our energy conundrum?
These musings do not detract from the important quest to unravel the gist of photosynthesis but must pie-in-the sky promises to be used for that purpose?
Mordecai Shelef (NAE member)
kearns on 05/09/2007 at 5:04 PM
25
zippo on 05/09/2007 at 9:49 PM
24
Like another person responding to this article mentioned, if you only get 1000 kw/m>2 minus losses from inefficiency, then shouldn't we be building an infrastructure that can provide adequate power within that envelope?
The problem with people today is that they want solar to work with contemporary power consumption models. Sadly, the fact remains that our current energy production methods are already struggling to meet that demand for power. Thus it is absolutely vital to work on decreasing the demand at the same time that we increase the supply.
nekote on 05/10/2007 at 8:56 AM
115
I'm in 100% agreement with energy efficiency.
Increased MPG, say 100 MPG, at a neutral or decreased aggregate lifetime cost will always be a good thing - extending range and/or decreasing onboard fuel storage requirements (weight and volume).
But, the true value of increased energy efficiency is determined by the cost of the available input energy.
Thus, economically, the lower the price of energy, the less value any increased efficiency has and the cost factor must always be overcome, if it is to be economically viable / worthwhile.
If storing sunlight can provide "oil" at, say, $1 / barrel, there is less value to any potential costs of increased efficiency than if the price is $100 / barrel.
And, if storing sunlight and later "burning" it is carbon / CO2 neutral, there is no net effect on man made CO2 production, regardless of efficiency.
carlii on 05/10/2007 at 5:26 AM
25
http://en.wikipedia.org/wiki/Geothermal_power
The MIT analysis shows Geothermal also has a valuable contribution to make to the world's energy usage.
http://geothermal.inel.gov/publications/future_of_geothermal_energy.pdf
Yet, Solar is more easily portable and can be integrated into above ground technologies.
Advances in the economics and energy efficiency are moving solar center stage.
scasteel on 05/15/2007 at 5:10 PM
1
techdufus on 05/29/2007 at 6:19 PM
1
wleighty on 12/28/2007 at 12:52 PM
1
All renewables except geothermal are time-varying in output, thus requiring storage to "firm" the energy supply at daily-to-annual scale, adding great strategic and market value. Electricity provides no affordable "firming" storage. Two transmission and storage schemes seem attractive, both proceeding from hydrogen production:
(1) Compressed hydrogen, transmitted by pipeline and stored in large, solution-mined salt caverns;
(2) Anhydrous ammonia, NH3, produced from H2 and atmospheric nitrogen, transmitted and stored as a liquid in pipelines and large, surface tanks. NH3 is valuable as both an N-fertilizer and as an energy carrier, storage medium, and fuel; the ICE will run on NH3.