[Renegade 13]

en.wikipedia.org/wiki/ethanol_fuel

For ethanol to contribute significantly to transportation fuel needs, it would need to have a positive net energy balance. To evaluate the net energy of ethanol four variables must be considered: the amount of energy contained in the final ethanol product, the amount of energy directly consumed to make the ethanol (such as the diesel used in tractors), the quality of the resulting ethanol compared to the quality of refined gasoline and the energy indirectly consumed (in order to make the ethanol processing plant, etc). Although a topic of debate, some research that ignores energy quality suggests it takes as much or more fossil fuel energy (in the forms of diesel, natural gas and coal) to create an equivalent amount of energy in the form of ethanol. In other words, the energy needed to run the tractors, produce the fertilizer, process the ethanol, and the energy associated with the wear and tear on all of the equipment used in the process (known as fixed asset depreciation to economists) may be more than the energy derived from burning ethanol. Two important flaws are cited in response to that argument: (1) the energy quality is ignored, which economic effects are large. Principal economic effects of energy quality comparison are the cleanup costs of soil contamination stemming from gasoline releases to the environment and medical costs from air pollution resulting from refining and burning gasoline. and (2) the inclusion of development of ethanol plants instills a bias against that product based strictly upon the pre-existence of gasoline refining capacity. The real decision should be based upon the long term economic and social returns. The first counter-argument, however, is specious, in that burning a gallon of cleaner ethanol is still pointless if it implicitly requires burning 2 gallons of dirty gasoline to create that ethanol in the first place.

Depending on the ethanol study you read, net energy returns vary from .7-1.5 units of ethanol per unit of fossil fuel energy consumed. For comparison, that same one unit of fossil fuel invested in oil and gas extraction (in the lower 48 States) will yield 15 units of gasoline, a yield an order of magnitude better than current ethanol production technologies, ignoring the energy quality arguments...It is suggested that an energy balance of 200%, or two units of ethanol per unit of fossil fuel invested, is needed before ethanol mass-production will become economically feasible.

According to a report by the Minnesota Department of Agriculture, when taking into account the energy needed to extract, transport and refine crude oil into gasoline, the final energy product of gasoline has an energy ratio of 0.805. That means ethanol production is 81% more energy efficient than gasoline, without factoring in the energy qualtity considerations. A 2002 report by the United States Department of Agriculture concluded that corn ethanol production in the U.S. has a net energy value of 1.34, meaning 34% more energy was produced than what went in. This means that 75% (1/1.34) of each unit produced is required to replace the energy used in production. The study also concluded that the energy used to produce and convert the ethanol was from abundant domestic sources, with only 17% of the energy used coming from liquid fuels, therefore, for every 1 unit of energy from of liquid fuel used, such as gasoline or diesel fuel, there was a gain of 6.34 units of energy. MSU Ethanol Energy Balance Study: Michigan State University, May 2002. This comprehensive, independent study funded by MSU shows that corn ethanol production has a net energy value of 1.56: it produces 56% more energy per unit volume of ethanol than it consumes. Nevertheless, as noted earlier, these relatively small energy gains are problematic, for they imply that between 2.79 (assuming net energy value 1.56) and 3.94 (assuming net energy value 1.34) units of ethanol must be produced for each unit of ethanol that can be sold to consumers. Actual net energy values might be improved by measures such as burning corn stalks (which are not fermentable using current technology) to run some parts of the corn ethanol production process that currently consume petroleum, gas, or ethanol (similarly to the way bagasse is currently burned to produce energy to run the ethanol production facilities in Brazil). As of 2005, ethanol production from corn may require an increase in the cost of petroleum before to become economically viable without government subsidies. Although for periods in the year 2005 ethanol traded for less than gasoline and diesel before any subsidy.