the way it is currently implemented.
Most studies indicate an EPR (Energy Profit Ratio) of 1 for corn ethanol from an energy standpoint, and 1.3 to 1.8 for corn ethanol once the value of coproducts are credited. Considering that 2/3rd’s of the energy consumed in corn ethanol production is in conversion (ethanol plant), this indicates opportunities for utilizing co-generation or renewables (wind) for most of this process energy. This is why I view ethanol in general, and corn ethanol spoecifically, more as a valuable energy carrier than an energy source. Process corn for ethanol using an energy input from renewable energy, renewable energy is converted to a valuable liquid fuel, with most of the food value of the corn remaining for consumption.
Just east of Ames, IA an ethanol processing plant is being built. In the brief for the project they advertised how the new plant will use the same coal supply delivered to the Ames, IA municipal electric plant 4 mi. to the west, thus resulting in savings. Problem is, this plant will burn coal to produce a liquid fuel with an EPR of 1 (corn ethanol) when you could produce a liquid fuel with an EPR of 5 from the coal directly. Thus, from a greenhouse gas standpoint, this ethanol is worse than petroleum derived fuels.
Once the crises arrives, ’energy balance’ will be the prime consideration in evaluating process feasibility.
With co-generation, this plant could have been located such that waste heat from the coal fired electric plant could have been utilized by the ethanol process. In addition, the Ames power plant burns local garbage, therefore waste material from the ethanol process could be burned (resource recovered, as they call it).
Another alternate is wind. Most of the corn belt and the high plains (potential switchgrass growing region) are reasonably close to areas that have good to excellent wind energy potential, most of which is essentially stranded. A major wind farm was just completed around 50 mi. to the NW of the plant site.
Corn ethanol is not a 'solution' to the coming energy crises. But I do think, under the scenario presented above, a viable mitigation option. Wind energy and corn ethanol are proven, scalable processes. We have the corn, we have the wind, why not marry the two as a mitigation/powerdown option until cellulosic ethanol and other developmental energy options mature. To me, this makes a lot more sense than pouring energy and money into developing tar sands or pre-oil shale.
Refer to Table 6 of the following report for a breakdown of energy use for corn ethanol production.
The Energy Balance of Corn Ethanol: An Update / AER-813
United States Department of Agriculture - July 2002
http://www.transportation.anl.gov/pdfs/AF/265.pdf Another consideration is that an energy system dependent on biofuels will be subject to crippling shortages during drought years. Can you imagine the effect of a ‘dust bowl’ series of years on a biofuel industry?
I believe that biofuels need to be exploited to their maximum practical extent. But any energy infrastructure system would have to address periods of reduced production of these fuels. One way to mitigate would be to build a ‘strategic coal stockpile’ with mothballed liquefaction capacity ready to be put on line in the event of a shortfall. Mothballed capacity and stockpiles are not a part of a Laissez-faire system.
In the coming world of energy scarcity, the current ‘free-market’ dynamic will be incapable of providing a relatively stable energy supply. We will need a diverse, redundant and integrated energy infrastructure that will require planning and coordination far beyond what ‘market signals’ (ie: price) can provide.
Once we have established a USEA (U.S. Energy Authority) that provides centralized high-level planning and funding for the energy infrastructure, we can begin basing infrastructure development on an energy balance basis. This would hopefully avoid the building of inefficient systems, such as the coal fired ethanol plant I cited above.
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