Agriculture Reference
In-Depth Information
food should not be used for energy. There is no doubt that a balance must be main-
tained. Corn producers, who have pushed for production of ethanol from corn grain
in order to raise prices, have been successful. However, it must be recognized that
corn production must remain great enough to meet food, feed, and export demands
as well as to produce ethanol.
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At this time, some amount of fossil energy is used in all bioenergy production.
However, the systems used to produce the two most common biofuels, ethanol and
biodiesel, produce more energy in the fuels and coproducts than that required for
their production (Durante and Miltenberger, 2004).
Net energy has been discussed and debated in the literature extensively. Authors
of these articles have used somewhat different assumptions and different domain
boundaries and as a result have delivered an array of conclusions about the sustain-
ability of biofuels. An extremely thorough analysis, attempting to level the differ-
ences in assumptions and domains of several previous reports, was published in
Science
(Farrell et al., 2006). The conclusions, although not above criticism, suggest
that biofuels are energy positive; that is, energy contained in the fuel is greater than
the energy (other than solar radiation) that is consumed in creating and delivering
the fuel to the point of use. They wisely pointed out that gasoline has a net energy
value of only 0.80, meaning that 20% of the energy in a gallon of gasoline is used
to extract, transport, and refine the crude and deliver the resulting fuel to the point
of use. Compare this to the net energy value of ethanol from grain of 1.30 and from
switchgrass (cellulosic ethanol) of 11.2.
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Production of bioenergy feedstocks has much the same requirements and makes use
of much the same resources as does production of human food and animal feed. This
has given rise to a controversy of fuel versus food and feed. It has been estimated
that there are sufficient land and water resources, and that sufficient infrastructure
can be developed to produce, transport, and process sufficient bio-based feedstock to
supply required bioenergy as well as to meet food and feed demands. However, the
justification for these estimates has not been adequately documented. And, even if
resources are sufficient, as the bioenergy production system develops there will be a
transition phase consisting of changes that will have perceived and real implications
for food and feed producers and consumers.
The rise in price of corn grain attributed to the amount being converted to etha-
nol has been linked to increases in prices of other commodity grains and to prod-
ucts made from them. There is concern that demand and price paid for biomass for
energy purposes will cause increased production of energy feedstock and decreased
production of crops for food and feed. Perlack et al. (2005) suggested production of
1 billion tons of feedstock for ethanol production will not cause significant changes
in commodity use and prices. Recent changes in Board of Trade values for corn
and other grains appear to contradict that suggestion—at least in the short run. The
