I'll start by pointing out that I see no value in E85 as it still requires 15% gasoline usage. E100(which isn't yet legal within the United States) should be used in all smaller passenger vehicles while E95 should be used for buses and freight vehicles. While use of ethanol causes a 15-30% loss in power, we're not running out of it as we eventually will with petroleum fuel sources. I'll note for the reader that this is not a global warming thread. I'm actually rather fond of the idea of global warming to an extent, in the regard that vast amounts of carbon have been removed from our ecosystem which I feel we should slowly reintroduce and that life seems to thrive in moderately warmer conditions.


Popular Sources of Ethanol

Miscanthus
Yield: 780 gallons/acre(7300 liters/hectare)
GHG Reduction: 37-73%
This is grown in Africa and southern Asia and, consequently, isn't the best choice as an American fuel source. It does, however, have a decent yield per acre and emits considerably less greenhouse gases.

Switchgrass
Yield: 330-810 gallons/acre(3100-7600 liters/hectare)
GHG Reduction: 37-73%
Switchgrass is approximately two meters tall, drought resistant, and grown in most North America. It has the same greenhouse benefits as Miscanthus but an unpredictable yield. The ease of cultivating is a significant bonus.

Poplar
Yield: 400-640 gallons/acre(3700-6000 liters/hectare)
GHG Reduction: 51-100%
Poplar, or members of its genus, is grown in most of the Northern Hemisphere, has an exceptable yield and ranges from mediocre to exceptional green house effect. While the statistics offer solid advantages, I have trouble accepting that we could cultivate and harvest poplar in the way we do corn and sugar.

Sugar Cane
Yield: 570-700 gallons/acre(5300-6500 liters/hectare)
GHG Reduction: 87-96%
Cane is grown in semi tropical and tropical regions including Hawaii and the Gulf Coast states. It has an appealing yield and the best(consistently) level of greenhouse effect.

Sweet Sorghum
Yield: 270-750 gallons/acre(2500-7000 liters/hectare)
GHG Reduction: Not available
This is grown in semi tropical regions including the same regions with the United States as Sugar Cane and is drought resistant. The yield ranges from a respectable level at best, to a laughable level at worst and there is currently no information regarding it's impact on greenhouse affect.

Corn
Yield: 330-420 gallons/acre(3100-3900 liters/hectare)
GHG Reduction: 10-20%
America's favorite crop. I'm fairly certain this is the only reason it's considered as a viable source of ethanol. It has the worst(consistently) yield and laughable greenhouse benefits.

In my opinion, the best sources of ethanol would be switchgrass and sugar cane, though other regions would likely profit from using other methods such as using miscanthus in Africa and Asia.


Methods of Use

Internal Combustion Engine
Four stroke ICEs pump a fuel mixture(in this case pure ethanol) and oxygen(as well as other elements in the air) into four or more combustion chambers each containing their own piston which, along with turning the drive shaft pushes the pistons from the other chambers along the process. This system provides exceptional performance but poor efficiency. To use ethanol in ICEs on the scale that we currently use gasoline would require such extensive use of our arable land(with any ethanol source) that it would do great damage to production of food crops. It is my opinion that the ICE should die alongside the use of gasoline.

Direct Ethanol Fuel Cell
DEFCs use platinum which is too expensive for mass production. Research being done implies that the platinum can be replaced by nickel, iron, and cobalt. They seperate electrons from the biomass to give a more direct energy conversion. In the Shell Eco-Marathon Europe the DEFC vehicle Schluckspecht showed itself capable of consistently attaining a fuel efficiency of 3000 km/l(7056 mpg). Admittedly, at a total weight of 25 kg(55 lbs) Schluckspecht isn’t exactly a passenger vehicle but some fine tuning may yield acceptable performance results with a significantly better level of efficiency than any existing ICEs.


We're a few years off from desirable usage of ethanol as a fuel source, but once the politicians, industry heads and consumers get their collective acts together we just may have something environmentally sound and inexpensive to replace our current fuel situation. We should, however, continue to deal with the price oil until we reach that rather than encouraging people to pursue such foolish ideas as the ethanol ICE or corn based ethanol.

Comments, clarifications, corrections, and counterpoints are all eagerly anticipated.

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During the journey we commonly forget its goal. Almost every profession is chosen as a means to an end but continued as an end in itself. Forgetting our objectives is the most frequent act of stupidity.
-Friedrich Nietzsche, The Wanderer and his Shadow

All good socialists have villas in Southern France. That's not the point.
-Eurosocialist

I can't see ethanol as a fuel source, there isn't enough raw material to produce the volume needed.

I heard that angae could be used instead of corn etc. While there is a lot of that, it serves a purpose too so taking it will certainly cause other problems.

__________________
Hope is the opposite of audacity. It's passive, an excuse for inaction.

Socialism doesn't create a rising tide that lifts all boats. It drains the lake and teaches the boat riders not to help themselves by rowing.

“What's the difference between Sarah Palin and Barack Obama?”

“One is a well turned-out, good-looking, and let's be honest, pretty sexy piece of eye-candy.

“The other kills her own food.”