March 31, 2006
-- by Dave Johnson
There is a great Kos diary, Daily Kos: Peak Sugar - Entropy Will Not Be Mocked, that discusses whether it takes more energy to make ethanol than the ethanol produces. Very interesting.
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I thought it got pretty incoherent, pretty fast.
But it did make one very important distinction -- between energy and fuel. The earth must be in energy equilibrium. There cannot be an "energy crisis". But there can be, and is, a fuel crisis.
It is always true that it takes more energy in to get a given amount of useful energy out. The issue for us is how much energy in is required to produce useful fuels, and more importantly, what kind of energy in is needed. Petroleum, when refined, is a terrific fuel for mobile machines. And even better, almost all of the energy that went into the production of a given amount of petroleum came from radiant solar energy stored in living tissue long, long ago. The energy we have to put in to "produce" petroleum is a tiny fraction of the total energy available in that "product". Perhaps the most expensive (in the sense of irreplacability) ingredient in petroleum is time.
In the case of ethanol, fertilizer and/or quickly consumed natural equivalents in soil, are required to produce fuel. If it takes a lot of fuel (or energy resources that can be converted to fuel) to produce ethanol, then ethanol may be a very, very expensive fuel. Maybe more expensive than alternatives. I don't know.
Fuel is about convenience and cost. Even if ethanol (or any other fuel alternative, like H2) turns out to be extremely expensive, it may still be a viable fuel, given how much we value the convenience that fuel provides and how much alternatives cost.
However, the cheapest fuel will always be fuel that is not consumed.
Posted by: Anonymous at March 31, 2006 8:39 AM
We don't have to use chemical fertilizers to fertilize fields. They are a recent invention. The alternatives used for a zillion years will still work. Check out organic farming.
If organic farming can sustain production of sufficent quantities of ethanol to make a dent in our fuel requirements, great. Given that organic techniques are not used on a large scale in the production of food, it seems quite unlikely to me that organic techniques can support "fuel argiculture" on a truly vast scale. I don't claim to know about this, but I do get suspicious of something-for-nothing schemes and perpetual motion machines when I see them. I hope I'm wrong.
Posted by: Anonymous at March 31, 2006 1:06 PM
Anonymous, my hunch is you are wrong. It's true that agribusiness doesn't normally use organic methods to produce our food, but if anyone wouldn't it would be them. Check out what Brazil's doing to fertilize those sugar cane fields, will you? I haven't checked yet, but my impression is they're being so careful about ecology, even using the pressed stalks to provide the fuel for the distilling process, that I'll bet they've got this one covered, too.
After all, for most of human history, farming was done on a very large scale using nothing but organic methods because there weren't any manufactured fertilizers. Organic farming is merely returning to earlier methods of farming. Geez, even in my childhood I used to hate driving past the spinach fields on our way to the "shore" because they stank from the dung used to fertilize them, and that wasn't considered "organic farming." Now dung is just one more by-product of agribusiness that's polluting the air, rivers and the water supply because they haven't figured out how to get rid of it. If they were to use it as fertilizer by plowing it into the fields before planting, it wouldn't stink.
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