•It isn’t factual. This is the author’s opinion. So we can say because it is just an opinion.
We don’t know if people actually produce livestock feed. By product of producing corn.
There is a reference which means it is true.
The National Geographic article gives an introduction to many of the issues. I thought it was
more balanced than some of the scientific literature that we looked at.
Define the NEB Ratio? Neb is net energy balance which is energy output subtracted by energy
input. We look at energy yielded from fuel vs. energy ingested into the production for example
of ethanol. Ratio is some cases for ethanol where it yields 25% more than in its production and
that is the NEB.
NEB ratio is done a little differently. It is the output of energy vs. input of energy. It is one
thing to remember…terminology NEB and NEB ratio. Ratio is output divided by input so think
of it for ethanol it is 25% more out than what you would put in to get that.
What is the significance of NEB ratio less than 1?
Put more energy input than we get output. If the output from a biofuel is less than input your
NEB ratio will be less than 1. So you are putting more into the production than what you are
What is the significance of that? If you saw an NEB ratio of less than 1?
It is costing you more to produce and overall it costs more. It is not necessarily going to be bad
in all cases if some of your inputs are not non-renewable fossil inputs. There is nothing that says
that if I want to drive from point A to o=point B that I have to do it with a fuel that has a ration
greater than 1. If I am relying on fossil fuel totally it means I have to get more fossil fuel out of
the earth and I burn and that is impossible, I can’t just say that. If you have another source of
energy for your inputs there is nothing inherently wrong with driving an ethanol car where it
took more energy than what you are burning.
Question #1 – part 2:
Neb ratio takes into effect everything involved in the production. Facility level all energy used
(including energy for employees to run the plant, etc.) the ratio is too generalized. When
comparing fossil fuels used in this ratio vs. renewable resources we could get a similar NEB ratio
if we use the same energy from coal as from solar. Solar energy is renewable so it makes no
BGYC58H3F.October,4,2007 TUTORIAL 2 3