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Scientists Develop First Practical Artificial Leaf March 28, 2011

Posted by Metabiological in Ecology, Science.
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This is all kinds of awesome.  Researchers have developed the first practical example of an artificial device capable of producing electricity through the process of photosynthesis.  In short and artificial leaf.

About the shape of a poker card but thinner, the device is fashioned from silicon, electronics and catalysts, substances that accelerate chemical reactions that otherwise would not occur, or would run slowly. Placed in a single gallon of water in a bright sunlight, the device could produce enough electricity to supply a house in a developing country with electricity for a day, Nocera said. It does so by splitting water into its two components, hydrogen and oxygen.

Holy renewable energy Batman.  This is the holy grail of renewable energy research.  A device that enables us to power our society using the non-polluting and completely renewable energy of the sun AND it helps to bring down atmospheric concentrations of CO2.  This is so good that at first I wasn’t sure this wasn’t a prank or an early April Fools joke but it seems to be legitimate.

Now if you’ll allow me to come down from cloud 9 for a moment there are of course practical considerations that need to be addressed.  First and foremost is cost.  Though the article mentions that one of the things making this new “leaf” practical is the fact that it uses lower cost materials than previous models it still remains to be seen whether the technology can scale up and compete with more traditional fuel sources.

Secondly, and more important in my opinion, is the question of water.  The device splits water into it’s component parts (hydrogen and oxygen) and uses them to make energy.  This of course means that for the device to work it will need a steady and most likely substantial supply of water.  The problem is that the water crisis is the biggest environmental problem you’ve never heard of.  Humanity is already using more than half of all world runoff for our own purposes leaving very little for the rest of the natural world.  Adding another human use for water may push us over the edge in terms of our water consumption.

I’ll add one caveat to that.  The article didn’t mention if the water had to be fresh.  Terrestrial plants need to use fresh water for physiological reasons, primarily to maintain levels of salt concentrations in their tissues (I’m not going into the details, Google it if you’re interested).  However there doesn’t seem to be any reason apparent to me why these artificial leaves couldn’t use salt water for their purposes.  If that turns out to be the case then my water concern is largely moot since salt water is one thing this planet has plenty of.

Finally I will offer not so much a problem as an interesting thought experiment.  If this device works by splitting water into hydrogen and oxygen then presumably at least some of that oxygen will be released into the atmosphere.  Done on a large enough scale, like if this technology takes over as our primary power source, it could conceivably alter the composition of the atmosphere enough to produce changes in the biosphere.  An greater abundance of oxygen could be beneficial to certain species of animal life allowing them to extract more oxygen with fewer breaths and therefore generate more energy at a lower cost to themselves.  Incidentally this is also predicted to happen to plants as CO2 concentrations rise.  Of course a greater abundance of oxygen could also lead to a greater risk of wildfires and could lead to oxygen toxicity in vulnerable environments.

Difficulties aside I am completely supportive of this kind of technology and look forward to seeing it break into the mainstream.


The Coal Question: An Old Problem For Our Time February 4, 2011

Posted by Metabiological in Ecology.
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I just finished reading an amazing book that clearly and articulately examines one of the most pressing issues facing the world today: the unsustainable use of fossil fuels as an energy source and how technological innovation may not be our savior after all.  Oh, did I mention the book was written in 1865?

“The Coal Question” by British economist William Jevons was at the time a topical examination of Britain’s dominant position in the world and how the might of the British Empire was in many ways tied to its easy access to high quality coal.  In the 19th century the British coal fields helped to drive the wave of industrialization that swept across the Western world, making Britain quite wealthy in the process.  Jevons breaks down both Britain’s reliance on coal and the implications that come with its exponential usage and eventual exhaustion.

Much of what Jevons writes would be immediately recognizable to anyone today who keeps up with the debates going on in the world of climate change and energy policy.  He noted that the exponential growth of coal usage in the UK could not be sustained indefinitely and that then current estimates of how long the supply would last were grossly wrong due to their plotting the increase in usage in additive terms rather than exponential.  He also pointed out that it wasn’t simply a lack of coal that threatened Britain’s superiority but a lack of cheap, high quality coal.  This is an important idea to keep in mind today when discussing peak oil because as anyone who works in the oil industry would tell you there is still a lot of oil left in the world.  The problem is that said deposits are either poor quality or in incredibly inaccessible places, either of which makes the mining and refining uneconomical.  It’s not just oil that drives our economy but cheap oil.  Take that away, without a substitute waiting in the wings, and our society grinds to a halt.

Oddly enough Jevons actually did examine alternative energy methods, though he does so in order to show their unsuitability.  Wind and wave energy he criticized for there intermitency and there lack of energy storage ability, essentially the same problems that plague those technologies today.  Hydroelectric power he was more favorable towards but ultimately rejected due to the need fow an appropriate site for the factories.  Oil was also rejected due to the limitations it possessed in his day.

It may be easy to criticize Jevons as just another Malthus for all the things he didn’t get right.  Though he was correct that Britain would eventually lose its status as the global superpower due in part to the end of its supply of cheap coal he was incorrect in predicting the end of prosperity.  He didn’t (and couldn’t have) foreseen the rise of oil and the development of nuclear energy.  However for all he got wrong it’s what he got right that makes him so applicable to this day and age and one idea in particular stands out: Jevon’s Paradox.

A common response both then and now to arguments like Jevon’s is that as technology advances it will allow us to use resources like coal more efficiently, using less of the resource to achieve the same result.  In short, technological progress with save us from our consumption.  What Jevon noticed is that while technological innovation does result in greater efficiency it does not result in a decrease in the products consumption but rather increases it.  The reason for this is simple: as technology makes it easier to extract and utilize a resource the price of said resource drops and as the price drops more people tend to use it.  More importantly though as the price drops people tend to find new uses for the product that had previously been prevented by cost limitations.  Thus even with increases in efficiency the use of something like coal can continue to grow exponentially.

This is the problem facing today’s world.  Even with the large amount of oil still out there (and as I mentioned there is a lot) technological progress that allows us to extract it economically and use it more efficiently will not save us.  With demand continuing to rise due to the growth of new economies it can at best maintain our usage, never decrease it.

Fossil fuels will run out and sooner than many people think but the major threat to our civilization is not the end of oil but the end of cheap oil.  Will another power source rise to take its place?  Honestly I don’t know.  Nuclear power has the potential but is very expensive to build and comes with its own set of problems.  Will wind, wave and solar overcome their intermittent nature and power storage issues?  Will anyone actually develop fusion power?

Right now no other option is ready to take over for oil and though a mixture of different methods (solar, wind, biofuels) will definitely go a long way towards doing so we must be prudent in the use of our most important resource.  Cutting back on personal demand by doing all the things experts keep telling us to do (drive as little as possible, buy local foods to reduce travel time, recycle, etc.) is a good place to start but unlikely to make much of a dent in global consumption.  Partly this is due to the relatively small percentage of oil use taken up by residential areas, with industry and agriculture making up the vast majority.  More importantly though is that  cutting back on personal usage would require a large segment of the population in order to be effective, something unlikely to happen in the numbers needed.

To truly reduce the amount of oil we use will require a two-pronged approach: technological advances that allow us to use less oil to achieve the same effect and social policy that keeps that keeps the price higher enough to discourage mass consumption.  Is this a great solution? No, frankly it’s not but it may buy us the time we need to create a better energy future.