[SGVLUG] Should we use biofuels? Was ...Tom & his Prius....

[David Lawyer]

On Sat, Jul 22, 2006 at 06:55:35AM -0700, Dustin Laurence wrote:
> On Wed, Jul 19, 2006 at 03:29:06PM -0700, David Lawyer wrote:
> 
> > switchgrass.  David Pimentel, a professor at Cornell, has analyzed the
> > energy costs of producing ethanol and biodiesel and claims that it
> > takes more energy to produce than is returned when you burn it as a
> > fuel.  This like trying to recover oil from a depleted oil field where
> 
> While looking for something else, I did find the reason I pay little
> attention to Pimentel and his lonely crusade against the energy balance
> of alcohol fuels (and apparently sometimes biodiesel, which is quite
> insane).  It's not particularly ethical to leave questionable research
> unchallenged, but this thread is more or less dead so I'm simply going
> to give a link to a listing of many other studies that always seem to
> contradict his position:

I already explained why to get reasonably accurate results you need to
use IO analysis.  I looked at a summary of the energy inputs from the
optimistic study and found no entries for human labor nor depreciation
of embedded energy of farm machinery.  Nor a lot of other energy
inputs to farms.  At least Pimentel does enter these energy cost.
> 
> http://www.journeytoforever.org/ethanol_energy.html
This was very biased.  They tried to imply the imprimatur of famous
universities just because some professor there has done incompetent
and/or biased research (it happens all the time).  Also a study they
presented looked at the average farm and the "best" farm.

Actually one should look at the worst farm, with the poorest soil,
most expensive water supply, poorest climate, worst transportation,
etc.  This is because if you are going to increase corn production,
for fuel then the good farms are already in use and one has to put new
land (inferior to most of the land already in production) into cultivation.  This is called marginal analysis.  

I searched for Pimentel and Leontief matrices and found nothing
appropriate.  So I suspect that Pimentel hasn't done it right either
and that his results may understate the energy content of ethanol.

To do it right is hard, since one has to calculate the energy content
of most everything using Leontief matrices.  

			David Lawyer