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This discussion relates to Technology Review's article A Biofuel Process to Replace All Fossil Fuels.

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  ka5s
  

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  07/27/2009 07:38 AM

  TANSTAAFL

  The USA in 2007 used about 20.68 million barrels of oil every day. Put another way, that's some 36 million gallons per hour. There being no such thing as a free lunch, replacing this will require moving more than 70 million gallons of fuel and feedstock every hour.  The article is not heavy on water requirements, either, which in our sunny Southwest is the least replaceable of resources.
  
  Still, good luck!  Let us find ten technologies each ten percent as efficient as touted and (other things being equal!) our problems are solved. 
  

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    Kevin Bullis
    

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    07/27/2009 08:46 AM

    Re: TANSTAAFL

    The algae will certainly need a lot of water. (I don't have the exact figures.) But it won't be fresh water--the algae grow in brackish water.

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      GaryB
      

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      07/31/2009 02:41 AM

      Re: TANSTAAFL

      " ... company says it is not using algae "

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  stradric
  

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  07/27/2009 08:35 AM

  Perspective

  I was puzzled how this could actually replace our fuel consumption.  Based on this page (http://www.eia.doe.gov/basics/quickoil.html), with their 378 million gallons of gasoline per day statistic, I calculated that we'd need 6.7 million acres of land to replace gasoline (based on the 20K / year).  And to me that seemed ridiculous.
  
  However, the total acreage of farmland in the US is around 922 million, which would make the 6.7 million acre requirement a rather small percentage. (http://www.ers.usda.gov/StateFacts/US.htm)
  
  Couple this great technology with an increase in efficiency for our transportation fleet and that requirement gets even lower.  Very promising stuff.

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    mkogrady
    

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    07/27/2009 01:30 PM

    Re: Perspective

    Use the fuels to power mass transit first, then individual vehicles.
    
    Mass transit is much more sustainable from an Energy Consumption perspective (rail installation is another matter entirely).
    
    Always was and always will be.

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      gregkbell
      

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      07/28/2009 11:22 AM

      Re: Perspective

      Instead of pounding our heads against the wall with social engineering projects (trying to force people to use mass transit), let's focus on allowing people to drive their cars with homegrown fuel.
      
      This will allow us to quickly reduce our foreign oil dependence, and thus consign the oil producing regimes of the middle east to the dustbins of history.

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        rttedrow
        

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        08/03/2009 08:23 AM

        Re: Perspective

        Alone, the savings from ceasing our petroleum-related aid and military adventures in the middle east and elsewhere ought to pay for this.

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      swimdad623
      

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      07/28/2009 10:21 PM

      Re: Perspective

      You may be surprised to find out that mass transit is not all that energy efficient.  In fact, Khosla Ventures commissioned a study that showed that an electric car uses less energy and generates less carbon than taking public transport.  The reasonong for this was that public transport often results in mostly-empty vehicles, and because transport stations uses a lot of energy even when nobody is there.
      
      http://khoslaventures.com/presentations/Hybrids.pdf
      
      As a New Yorker, this seems obvious to me.  Outside of rush hours, the busses are usually empty, the NYC subway isn't overly full, and the station lights are always on 24x7.  In addition, the first air-conditioned station just opened, and a lot of the stations are going to be retrofitted with cooling systems.

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        mkogrady
        

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        07/29/2009 08:33 AM

        Re: Perspective

        The Khoshla paper cites NY Heavy Rail as a reference - NY has higher labor costs, restrictive regulations and a whole litany of issues that make an apples to apples comparison unrealistic. I believe that when you calulate usage over a 7X24 period, the costs escalate considerably as well. The website materials here also target India in particular, not US cities. The government regulations in India are drastically different than the US.
        
        Thought #1 - develop a Light Rail Solution with economies not found in heavy rail. Basically reengineerig the mass transit with fuel efficiency in mind and place an emphasis on the fact that the US can realistically produce X amount of fuels ourselves. The strategy would be to build the solution to use only the fuels or power sources we can produce ourselves.
        
        Thought #2 - Run Mass Transit for peak times only not 24 hrs per day. Most traffic congestion, parking congestion etc all happen during normal business hours. By moving all the workers using mass transit during this peak period, you would drastically improve those cost figures. After working hours, shut the system down for daily maintenance. A 5AM to 8PM Operations M-F window would cover the larger percentage of people who can leverage mass transit most effectively. On weekends, run the systems from 8AM to 6PM or commuters can use their own vehicles.
        
        A key point to remember too is that even a normal ICE vehicle runs much more effciently when you run it at a steady state (ie not stop and go traffic). My 2003 Ford Taurus gets an average of 23 mpg in my daily driving, but just last week I had to take my son to sign up for classes on the other side of the state and my drive at 75mpg in steady traffic, my mileage jumped up to almost 28 mpg. Multiply this type of improved efficiency by millions more drivers and the fuel consumption figures drop dramatically. Getting more cars OFF the road means there will be improved efficiency for everyone who HAS to drive regardless of the type of fuel they fill their vehicle with.
        
        
        Thought #3 - buying all electric implies these vehicles will be affordable. The readers of this material are most likely well educated, upper middle class people, and buying a $30,000 + car is not a huge burden. However, there are a larger number of poorer people who need mass transit to make a living. The Hybrid paper pretty much hammers down the fact that being green means you have to have "green backs" in your pocket before they're affordable.
        
        Don't get me wrong though. I think Electric propulsion is the way to go, but we're a heck of a long way off before this becomes an affordable reality.
        
        The Khoslav site has a paper that specify's Bicycle Commuting for the 600 million Indian citizens too. This would work in the US in sunbelt areas for many US workers and commuters and parts of the country could use this mode of transport for 30 - 40% of the year.
        
        Utlimately it will boil down to Alternative Fuels, Mass Transit, electric propulsion and human powered vehicles with Telecommuting being a huge tool as well. There will always be a reason a person needs to go from point A to point Z, but what tool they select will be determined by their affordability. A $40,000 Hybrid Electric vehicle can easily be replaced by a laptop, internet connection and cell phone for many people. Conversely a light rail solution can be replaced by a well built bicycle (or electric bike).
        
        Given more choices, I believe commuters will pick the one that fits their budgets best (or combo's) regardless of how energy independent it makes the US, and how much carbon we don't put into the air.

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    yoyofella
    

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    07/27/2009 05:17 PM

    Re: Perspective

    I think your calculation is a bit off. According to the DOE link you provided, the daily US petroleum consumption is just 20milion barrel/day, which means it's about 7.3 billion barrel/year.
    
    
    Assume Joule Biotech's accurate in their 20k barrel/acre annual production prediction, that means we need just 365,000 acre, or about 570 square miles (think 24milex24mile). see calculation here
    
    Still a huge size, but definitely manageable. Another way to picture this: the Sunny city of Phoenix, AZ is 475 square miles. so in order to produce enough petroleum for the entire US using this tecnology, we just need a little more land than a US city.

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      bruce1q
      

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      07/27/2009 08:24 PM

      Re: Perspective

      The  article claims 20k Gallons of fuel/acre NOT 20k barrels.
      So the required acreage would be 42x your calculations if you used barrels.

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