It sounds like a great idea. A renewable alternative energy source, made from crops already being grown for food, which will reduce the greenhouse gasses being pumped into the atmosphere and help prevent global warming.

Ethanol, when mixed with gasoline, is an alternative energy capable of extending the life of the world’s fossil fuels.

It’s also a source for the hydrogen in fuel cells, themselves alternative energies.

In 1999 car manufacturers began producing automobiles which could run on ethanol concentrations between 0-100%. All 2006 U.S. car are compatible with gas/ethanol mixtures containing up to 10% ethanol. Some states only allow the sale of 10% ethanol gasoline.

So what’s not to like about ethanol as an alternative energy source?

Ethanol, although promoted as limiting the use of fossil fuels, is actually 34% less efficient than 100% gasoline. That equates to 34% fewer miles per gallon; so the 90/10 gasoline/ethanol mix, is 3% less efficient than straight gasoline, costing the consumer three cents more on the dollar for fillups.

And that‘s not the only strike against ethanol as an alternative energy.

The U.S. Federal Government supports ethanol as having a “positive net energy balance”–meaning that the energy needed to produce it is less than the energy it produces. But there is evidence to the contrary.

A 2005 study by Berkeley professor Tad Patzek examined all the processes involved in ethanol production requiring the use of fossil fuels–the energy used in fertilizer and pesticide production and application, in transporting the crop to the ethanol extracting plant, and in the extraction process itself–claims that 65% more energy is expended in creating ethanol than the ethanol produces when burned.

Not an alternative energy; a drainer of energy.

Advocates of ethanol point out that the farming and extraction practices Patzek’s study examined are being replaced by more efficient ones, and that ethanol certainly deserves continuing support as a possible alternative energy source.

In ethanol’s favor as a fossil-fuel sparing, alternative energy? The ongoing availability of corn. Now is the time to work on changing the ethanol production process to a demonstrably energy-and-cost efficient one.