Comments on: Against the Grain: What Were They Thinking II?

By: Earl Killian

Earl Killian — Mon, 21 Apr 2008 03:20:06 +0000

Dan Seidel, I agree about gas hog vehicles, which is why I’m not a big fan of ethanol. Internal combustion engines are only 21% efficient or so, which helps make them gas hogs. (The bigger part of the “hog” is the sheer weight of the vehicles, which is unnecessary.) A good reason to turn to electricity is that it is as efficient as internal combustion is inefficient. The grid is 92% efficient at delivering electricity to our plugs, we can convert it to DC at >90% efficiency, store it and recover it in batteries at >90% efficiency, and use that electricity to turn motors at >90% efficiency. Moreover, we can convert sunlight to electricity at 30% efficiency, which is two orders of magnitude better than plants can convert sunlight into stored starch and cellulose.

By: Dan Seidel

Dan Seidel — Mon, 21 Apr 2008 02:12:35 +0000

Not many folks who criticize ethanol realize that its only the starch that is used to make ethanol. The protein portion of the corn is still usable and is fed to livestock. But if you really want to describe the problem its consumption. This country needs to get off the gasoline binge. We as a nation are drunk on our gas hog vehicles.

By: David B. Benson

David B. Benson — Fri, 04 Apr 2008 18:21:01 +0000

David Ahlport — All the energy sinks you name can in principle be provided by bioenergy. There is ample available, just undeveloped.

By: jmd

jmd — Fri, 04 Apr 2008 07:39:23 +0000

I think the point was that although native prairie biofuels would indeed require energy to harvest transport, and process, growing them wouldn’t require any fossil fuel inputs because theoretically a natural prairie ecosystem would be self-contained. In practice it wouldn’t be so simple, because as was pointed out, energy removed from they system in order to use it somewhere else would have to be replaced somehow. The idea is probably to use a greener source than fossil fuels.

By: David Ahlport

David Ahlport — Fri, 04 Apr 2008 03:52:26 +0000

==it would also provide a source of biofuels that in itself requires no inputs of fossil fuels (energy is needed to harvest, transport, process).==

Says who?
You take stuff out, take it elsewhere, and burn it.

Unless what you take is ENTIRELY drawn from the air, by definition it will require inputs.

And unless all this machinery used to harvest it, transport it, store it, process it, refine it, and distribute it requires 0 energy. That also requires INPUTS.

You sir, are claiming that the laws of thermodynamics, and conservation of matter magically don’t apply to biofuels.

By: Jeremy

Jeremy — Fri, 04 Apr 2008 02:34:59 +0000

A lot of the same problems apply to other sectors as well. In my state of Tasmanian, Australia we are replacing prime agricultural land with tree plantations. While this can be seen as carbon positive (or at least carbon neutral over the long term), it means that the agricultural demands still need to be met elsewhere; but they tend to be moved to more marginal land that has lower yields and requires more energy; which is ok economically because the loss of land is pushing prices up. If tree plantations are effectively carbon neutral (since the trees are used for paper, which eventually decays) but the agricultural is becoming more energy intensive and clearing more land, the end result is an increase in carbon emissions, rather than a decrease.

By: David B. Benson

David B. Benson — Thu, 03 Apr 2008 17:17:38 +0000

In yesterday’s TNYT (or the day before), an article pointed out that this year farmers are switching back to soybeans rather than so much corn. In part this has to do with field rotation schemes.

By: Andy

Andy — Thu, 03 Apr 2008 14:32:46 +0000

I have two comments on this post. First, here is the Ecological Society of America’s position on biofuels which notes that restoration of native prairies would not only sequester large amounts of carbon (it is the conversion of forest and grassland to crop land which accounts for the first anthropogenic increases in atmospheric CO2); it would also provide a source of biofuels that in itself requires no inputs of fossil fuels (energy is needed to harvest, transport, process). http://www.esa.org/ pao/ policyStatements/ Statements/ biofuel.php

Second, If, as many folks believe, we are not subject to Malthus’s prediction of food shortages, then why don’t we have enough arable land to grow both food and fuel? It is my though that the need for biofuels has only brought the oncoming Malthusian predictions to bear out a little sooner than would have occured under our continuously increasing global population.

Let’s take advantage of this glimpse of the future and stop using our food for fuel, restore degraded semi-arable lands to native grassland (CRP lands) and forest; a workable source of biofuels.