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This discussion relates to Technology Review's article Solar-Power Breakthrough.

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  whynot
  

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  08/01/2008 02:25 AM

  nice breakthrough, but?

  It seems like this may be a nice scientific break through, but Meyer's claim that "this is probably the most important single discovery of the century" seems a little overly sensationalist
  
  A couple questions:
  1.  Wouldn't creating H2 and O2 then recombining them in a fuel cell be way less efficient (and more expensive) than just using batteries?  Good fuel cells are typically less than 60% efficient at generating power.  So if we assume that the dr's process is 90% efficient and that the power electronics to regulate the voltage both to the Dr's device and then from the fuel cell to the outlet are each 95% efficient then you get .9*.6*.95*.95 = .49.  You lose about half your energy!  If on the other hand you use batteries that should easily be able to get 90% efficiency on charge and discharge (depending on the chemistry and charge/discharge rate this could be quite a bit higher), and you assume the same losses for the power electronics .9*.9*.95*.95 = 73%. 73% is much better than 49% and you eliminate the need for all those expensive storage tanks and fuel cells.
  
  2.  If you have access to a fuel cell anyway, couldn't you just run it in reverse to separate the H2 and O2?  Perhaps the idea is that a reversible fuel cell would be more expensive that the combination of the Dr's device and a more conventional fuel cell.  For a paper on a reversible fuel cell with round trip efficiency of ~50%, see link below: http://gltrs.grc.nasa.gov/reports/2006/TM-2006-214054.pdf

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  • 
    Wireless Dongle
    

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    08/01/2008 03:50 AM

    Re: nice breakthrough, but?

    Your questions are sensible, but the photosynthesis focused research produces energy without any noticeable costs (if I understood the article properly). Of course there is the machine manufacturing cost that harnesses the energy from the sun, but then it uses a catalyst that reforms itself ('heals itself' according to the article).
    
    On the other hand your figures are based on extensive refinement to fuel cell technologies. This technology is still a new breakthrough and it is logical to expect it to evolve into becoming more efficient than current day fuel cells in my own opinion.
    
    Also since there is a  one time cost of manufacturing the apparatus that collects Hydrogen and Oxygen and then the catalyst is self-healing, you can think of it as free energy in a way.

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  • 
    libraryman
    

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    08/01/2008 08:59 AM

    Re: nice breakthrough, but?

    Excuse me but you are missing something in your equation, the efficiency of the power generator/converter.
    In the first equation you have the artificial photosynthesis efficiency but you do not include the efficiency of current solar cells producing electricity (or the efficiency of any other power generating device).
    If you set up your equation properly with all the parts you would have seen this. Units have to balance.
    The replacement cost of batteries is a huge factor as the other respondent points out. Just to replace the lithium ion batteries in those new cars costs hundreds of dollars and must be paid every 4 years or so.

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    Bruceahz
    

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    08/01/2008 09:45 AM

    Re: nice breakthrough, but?

    A benefit of making H2 and later putting it into a fuel cell (instead of just using a battery for storage) is transportability. Moving a battery to where you want to use the electricity is a non-trivial exercise.
    
    The problem with plug-in hybrids is the length of time it takes to recharge their batteries. A fuel cell vehicle can "recharge" in the same time as a gasoline vehicle.
    
    Note that a couple of months ago, in this space, there was a discussion of a company trying to implement a battery-swap-station system for overcoming this extended recharge problem.

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    • 
      Siphon
      

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      08/03/2008 10:06 AM

      Re: nice breakthrough, but?

      Moving hydrogen to where you want to use the electricity is a non-trivial exercise with losses that will always be bigger (by entropy) than advanced batteries.
      
      Hydrogen as an energy carrier is a total loser.

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• 
  devassocx
  

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  08/01/2008 02:26 AM

  I hope its a breakthrough

  Its all interesting and hopeful.
  
  However, this year I have probably read of a dozen
  or so breathroughs regarding our energy problems.
  
  Later, there appear to have been serious difficulties of one kind or another.
  
  So sometimes, they hype gets ahead of the reality.
  I hope thats not the case here.

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  • 
    javs
    

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    08/01/2008 08:49 AM

    Re: I hope its a breakthrough

    I also hope it's a breakthrough. Researchers are like baseball players they make homeruns, but also strike out. What's needed is that they keep taking tunrs at bat. At some point the solar home run is bound to come.
    
    To increase the incentives for researchers to take turns at bat, I have suggested to take down the barriers on the development of the resources of the demand side, as follows:
    
    The electric power industry regulations have a strong barrier to the development of the resources of the demand side. For any solar power breakthrough to be integrated to power system planning, operation and control a new market architecture and design is required to eliminate said barrier.
    
    The article is a good contribution to TR readers about one of the most important kinds of uncertain generation.

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    • 
      vv111y
      

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      08/01/2008 02:21 PM

      Re: I hope its a breakthrough

      A scenario I was thinking (and I'm sure many, many others) is to make the US's SW desert our new 'solar Saudi Arabia'. CA, AZ, NM would be the 'have' states. Distribution of electricity to the rest of the country, and manufacture of synthetic fuel on site (which gets shipped to rest of the continent).
      Given the hurdle(s) you've described, how bleak is the outlook for something like that?

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      • 
        ted122
        

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        08/03/2008 04:28 PM

        Re: I hope its a breakthrough

        I agree, make sure to add Nevada to solar sink.  This needs to be a project the size of the Interstate Highway system.  We shouldn't wait until the perfect solar technology system is developed.  Whoever is President next, should tackle this project make it WWIII in scope and intensity.  This would quickly cure the oil speculators, starve the Middle East and take them out of the equations.  The US should lead the technology and throw everything we have at the project.  A project of this size stimulate the economy and give us something "real" in return.    The environmental wackos would need to get out of the way.  There will be room for the wildlife and I'm certain some species might even find life better. 

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    • 
      javs
      

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      08/01/2008 07:06 PM

      Re: I hope its a breakthrough

      Kevin,
      
      Is there a reason why the following was taken out of my post
      
      ... The EWPC article Uncertain Generation is Here to Stay takes the idea into the context of the Third Industrial Revolution. . . . . . . With regard to solar distributed generation, please read the EWPC article Nanosolar Breakthrough and the Old Paradigm. Research for scheduling and integrating ... solar power to power systems planning, operations and control, will be part of the next stages. . . . . . . To understand what to do first in the wider, and highly uncertain, legislative and regulatory context, TR readers should consider reading the EWPC article Leadership Answers What to do First, whose summary is "The answer to the question of what to do first is for the global power industry to get out of the wrong jungle to produce a EWPC based EPAct as soon as possible. That is the kind of leadership needed to face the inevitable fundamental changes required to significantly reduce today’s legislative and regulatory uncertainty."
      
      Please let me know,
      
      Thank you,
      
      José Antonio

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