“Great, another process that uses more energy that it makes,”
I thought I read somewhere that it takes less energy to make this ethanol than crude. Considering the cost of offshore rigs and artic drilling, this might make sense.
I’d be interested in reading that if you can find it.
I think this old argument that "it takes 1.x BTUs of energy to produce 1.0 BTUs of product" is very deceptive as it appears as if you must add some extra energy from a second source to produce the product. I don't think it works that way.
I believe the truth is that you add, for example, 1.5 units of feed stock into the system and produce 1.0 units, you have "expended" only the 0.5 units in the process. It is a positive gain. This is how crude is turned into gasoline, by putting 1.x BTUs of crude energy in, and getting 1.0 BTUs of gasoline energy out. The crude can't be burned in a car, but the gasoline can, so a fraction of loss in the process is OK.
Similarly, if you took 1.5, or even 2.5 or 3.5 BTUs of cudzu and turned it into 1.0 BTUs of ethanol, that's still a positive gain, because the cudzu is worthless to power a car, but the ethanol works.
These actual numbers floating around are "true", but they're deceiving, because it appears as if some second source of energy is being added to produce the product that results in some kind of negative return, and that's not the truth.
I've used lots of "I think" wording in here. I can't find a source on the net where this is verified, but I have heard this argument made in the past, and it explains why these processes are done when it would seem on the surface as if there's some sort of fraud going on.