How much more environmentally friendly are electric cars and ethanol
powered cars compared to a typical gasoline car?  Does the pollution
output from the power plants or farm machinery/ethanol plants negate
the gain from the lack of pollution from the gasoline vehicle itself?

Hello brandoncolorado,

Thank you for your question.

Electric cars are very efficient compared to the cars most people drive.

Here is a very informative page on electric car emissions:

The Case for Electric Cars
http://www.teslamotors.com/display_data/21stCentElectricCar.pdf 

You are correct in hypothesizing that the output from the plants
negates the lesser pollution from ethanol-fueled cars, to an extent.

It was previously thought that ethanol was very inefficient; however,
new studies have come out this year saying that ethanol is not as
inefficient as previously thought, is more efficient than regular
fuel, and is getting better with new technologies being developed.

National Geographic
Ethanol Study Released
http://news.nationalgeographic.com/news/2006/01/0126_060126_ethanol.html 

As Hedgie pointed out, ethanol is ethanol, but there are different
ways of making this molecular compound.  In particular, the Brazilians
use sugar to make ethanol, and their method of using sugar is much
more efficient than the American way of utilising corn.  Americans
could support ethanol from sugar; it's quite a long story of why they
do not.

Sugar farmers in America get enormous federal government subsidies. 
The price that farmers from other countries sell sugar is very low
compared to that of American sugar, so Americans would make no money
with sugar if they sold it at market value.  They get huge subsidies
and sell sugar at a high price.  Sugar from other countries is slapped
with huge tariffs, so that it cannot compete in the American market
with American sugar.  Sugar is more expensive in America than most
countries in the world.  If you travel to any other country and order
a Coca-Cola, it has sugar in it.  In America, it doesn't; it has high
fructose corn syrup instead.  HFCS is very unhealthy compared to
regular sugar, so this is not a good thing at all, except for the corn
farmers.  Most processed foods in America do not have sugar but HFCS.

So, Brazil has cheap sugar and can make ethanol out of it very
effectively and at huge volumes.  America would be helping the world's
environment by supporting the Brazilian sugar industry or at least
letting sugar in America fall to market rates and using it for ethanol
instead of corn, which is entirely inefficient.  However, America has
chosen to pass specific laws charging large tariffs on Brazilian sugar
and Brazilian ethanol, which were supported by almost all
representatives.

It is not clear that corn ethanol should be completely abandoned in
the US, though, because it can eventually be made a more efficient
process.

Search terms:
electric car efficient
ethanol efficient

If you need any additional clarification, let me know and I'll be glad
to assist you.

--keystroke-ga

Thanks

My understanding (from a large amount of reading news/articles... for
whatever that's worth) is that hybrid electric cars are fairly good...
the reduced emmissions is very significant and the batteries recharge
themselves while driving.  Ethenol requires more energy to produce
than cars can get out of it.  So to use ethenol (with current
technology) is a losing battle as making energy with coal or gas makes
much pollution and costs as much or more than just buying gas for cars
would.

I have seen/heard rumors of a different kind of ethenol than is
currently readily available.  This newer ethenol is supposed to be
much more efficient, we'll see in a few years if this starts to pan
out.

excuse me Jack,

but ethanol is ethanol. It is a chemical name and so, there is only one ethanol.

find it here

www.strw.leidenuniv.nl/ astrochem/molecules.html

Hedgie,

Thanks for pointing out my poor language choice.  By "different kind
of ethanol" I did not mean to talk about a different product, but a
different process.  Ethanol is created by several different processes
right now, and more are being developed.  These new processes could be
(and some are expected to be) much more efficient than the current
inefficient processes.

I have not heard much about the new processes, but a friend of mine
who works in the biotech industry told me that they are making great
progress towards reasonable production of ethanol.