tdmeeh’s Recent Comments

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  Algal oil energetics

  Want to learn something about the energetics of algal oil production? See below.  

  http://www.massey.ac.nz/~ychisti/TLReprint.pdfOn High energy requirements make the manufacture of algal biofuel prohibitive posted 8 months, 1 week ago 35 Responses

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  Enough with the dogma

  I am continually frustrated by the attitude that all biofuel schemes are net negative propositions and are thus worthy of ridicule.  Visit the WBM conference website and you will see a substantial showing of algal, cellulosic, and waste stream fuel folks.  In the right context, these technologies represent important wedges in the effort to reduce GHG emissions.On Bob Geldof takes a big ol' swig of biofuel posted 8 months, 3 weeks ago 6 Responses

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  More maps

  For more maps of flooded coastal areas with sea level rise, see Jonathan Overpecks's website:

  http://www.geo.arizona.edu/dgesl/research/other/climate_c ...
  On West Antarctic ice-sheet collapse means more catastrophe for U.S. coasts posted 9 months ago 5 Responses

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  Another view on LCOE

  Here is a link to an interesting paper on levelized cost of electricity with and without external environmental costs included.

  http://www.warren-wilson.edu/~tmeehan/Sovakool_2008.pdf

  Best,

  TimOn Proposed renewable-energy bill is better than nothing posted 9 months ago 26 Responses

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  Got grass?

  Jon,

  I'm glad you called attention to the greenhouse gas output due to space heating.  It's especially important in the northern half of the country.  I came across a neat report recently that explains how native perennial prairie grasses grown on marginal farmland can be an excellent source of energy for space heating.  

  1. Grasses are native and you mow them once after the growing season, so fields provide decent wildlife habitat.
     
  2. The annual yields are pretty darned high (~10 tonnes/ha) even with minimal fertilizer inputs. Legumes can be sown in so nitrogen input is reduced.
     
  3. You densify the grass after cutting (briquettes or pellets) which is not a very energy intensive or technologically involved process. The end product is pretty portable.
     
  4. Then you burn it in a boiler. There is no further processing so the net energy yield is pretty high (13 units energy out per 1 in).
     
  5. The plants are perennial so tillage is minimal and carbon accumulates in the soil from root biomass production.
     
  6. Farm income from harvested grasses offsets the drive to convert CRP grasslands to corn.

  There has been a lot of talk about switchgrass as a feedstock for cellulosic ethanol production.  But the net energy yield for switchgrass to ethanol is much lower.  Maybe we should use wind/solar/geothermal electricity to drive our cars and grasses to heat our houses.

  Just a thought.

  The link to the report:

  http://www.agrecol.com/AgrecolADDReport.pdf

  Another good grass site:

  http://grassbioenergy.org/

  Best,

  TimOn Slicing and dicing global greenhouse gas data posted 9 months, 4 weeks ago 17 Responses