|
Wednesday, May 09, 2007 Supplying the World's Energy Needs with Light and WaterA leading chemist says that a better understanding of photosynthesis could lead to cheap ways to store solar energy as chemical fuel. By Kevin Bullis
While researchers and technologists around the world scramble to find cleaner sources of energy, some chemists are turning to nature's own elegant solution: photosynthesis. In photosynthesis, green plants use the energy in sunlight to break down water and carbon dioxide. By manipulating electrons and hydrogen, oxygen, and carbon atoms in a series of complex chemical reactions, the process ultimately produces the cellulose and lignin that form the structure of the plant, as well as stored energy in the form of sugar. Understanding how this process works, thinks Daniel Nocera, professor of chemistry at MIT, could lead to ways to produce and store solar energy in forms that are practical for powering cars and providing electricity even when the sun isn't shining. What's needed are breakthroughs in our understanding of the fundamental chemical processes that make photosynthesis possible, according to Nocera, a recognized photosynthesis expert. He is studying the principles behind photosynthesis and applying what he learns to making catalysts that use solar energy to create hydrogen gas for fuel cells. Nocera's goal: a world powered by light and water. Technology Review: What's the biggest challenge related to energy right now? Daniel Nocera: The real challenge with energy is the scaling problem. We're going to have this huge energy need, and when you start looking at all the numbers, there's only one supply that has scale, and it's the sun. But it's still a research problem. Technologies all follow lines; then there's a discovery and a new line that's better. We're on a very predictable line now in solar. Most things you hear about are incremental advances. TR: You're studying photosynthesis to get ideas for how to convert sunlight into a chemical fuel--hydrogen--for use when the sun isn't shining or in powering fuel-cell vehicles. DN: You can use the electricity directly when the sun is out, in places that have sun. [But] you need storage. There's absolutely no way around it. I am distilling the essence of photosynthesis down to be able to use it. TR: Why is photosynthesis attractive in finding a source of clean energy? DN: [Photosynthesis] does three things. It captures sunlight, and [second,] it converts it into a wireless current--leaves are buzzing with electricity. And third, it does storage. It stores the converted light energy in chemical energy. And it uses that chemical energy for its life process, and then it stores a little. It turns out [that] photosynthesis is one of the most efficient machines in the world for energy conversion. But it's not great for storing energy because that's not what [a plant] was built to do. It was built to live and grow and reproduce. And so that's the approach we take. Can we now do what the leaf is doing artificially, which is the capture, conversion, and storage in chemical bonds? But my device doesn't have to live: it can take a lot more of that energy and put it into chemical bonds. |
Audio »
Share »
Digg this
Add to del.icio.us
Add to Reddit
Add to Facebook
Slashdot It!
Stumble It!
Add to Newsvine
Add to Connotea
Add to CiteUlike
Add to Furl
Googlize this
Add to Rojo
Add to MyWeb
Favorite
Print
E-mail
Solar-Power Breakthrough
07/31/2008
Comments
mkogrady on 05/09/2007 at 1:24 PM
88
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
114
http://www.greenandgoldenergy.com.au/Documents/SolarEnergyTheOnlyGameinTown.pdf
nekote on 05/09/2007 at 2:27 PM
114
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
114
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
24
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
114
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.