Response to Comment of my Review

Oh, we're talking about biodiesel if is wasn't immediatly clear from the title on the post. I posted a review of a major National Renewable Energy Laboratory (NREL) study on soy-derived biodiesel. J.C. Winnie of After Gutenberg later published an extended comment on my review on his own blog that I would like to respond to.

The first statement I take umbrage with appears to be confusion over one problem with the energy return on energy invested accounting used within the NREL study:

The authors failed to take into account any power input other than fossil fuel, i.e., they omitted electricity, which is a predominant energy input.

This isn't what I said. I stated that "for the purposes of this study, this means the hydroelectric and nuclear power share," (of electricity). The study used a bouquet of energy sources intended to be representative of the USA as a whole. In the States, the share of nuclear and hydroelectric power (20 + 3 %) is not very big, so they are not omitting all of the electricity consumption from their energy balance equations, just a chunk of it. In a nation such as France, Canada, or the nordic and baltic states this would have had a much bigger impact.

I also said that the coproduct accounting stank because the meal is worth less (on a mass basis) than the oil, whereas NREL's accounting gave equal value to not just the meal but also the water content and hulls of the beans. Winnie casts some doubt on this assertion:

In another post, a Missouri farmer indicated that the meal when used as a high-protein animal feed is worth more than the biodiesel at current prices. Yet it may well depend upon where one looks and who does the looking. Reportedly, Biodiesel production in Indiana is rapidly increasing because the price of soybeans have become relatively cheap compared when compared with markets in other grain-producing regions in the Midwest, plus the demand for fuel in Eastern states is increasing.

There is no need to rely on anecdotal evidence in this case. Entering the terms "wholesale price soy meal" into Google yields precisely the data we desire from the University of Cornell. If we open up Table 9(2).xls we'll find that a bushel of soybeans yields an average of 11.33 lbs. of oil and 44.26 lbs. of meal for the year 2004/5. We can calculate from the table that soy oil has a value of $0.2321/lbs. while meal has a price of $0.0915/lbs. Sometimes I want to leave something as an exercise to the reader.

The last comment I would like to make regards the closing discussion:

Speaking of accounting, such a narrow perspective omits acknowledgment 1) that, whether in Europe or North America, biomass-based power generation is likely to remain more cost effective than biofuel production, or that, as Tad Patzek continues to remind us, bottom line, “There simply isn’t enough arable land available in the world to grow the crops that would be needed to fuel our oil habit.”

This is a bit of a non-sequitur, in that my original post didn't really attempt to address those issues. Entropy Production is a blog; an evolving narrative. I can't write a book chapter every post, so no one post will be a self-contained document. I only consider biomass energy solutions useful if they produce a portable, calorific, liquid fuel. Generation is just not on my agenda; there are too many better ways to generate electricity without invoking issues like soil erosion.

With regards to Tad Patzek (and by extension David Pimental) they both like to include energy amortization charges for all the capital infrastructure used for the production of biofuels. The NREL study does not deal with this issue. It is a topic that will have to be saved for another time.