by Tom Pritchett
Some have argued that bio-fuels, and more specifically bio-ethanol are the answer to America’s energy problems and our production of greenhouse gasses. Unfortunately, that is not the case. The U.S. uses fossil fuels primarily for four purposes: the generation of electricity, transportation, direct heating, and as raw material in manufacturing processes. The bulk of the greenhouse gasses (as CO2 equivalents) are emitted from the first two categories with the generation of electricity being responsible for 40.5% of the 2004 emissions and transportation being responsible for 32.8%. Obviously, to address overall energy needs and greenhouse emission, both these usages must be addressed. Unfortunately, bio-fuels only addresses the transportation usage and then, currently at a relatively insignificant level. Currently, bio-ethanol is not used for the generation of electricity and the only a very small fraction of bio-diesel is so used.
Because the generation of electricity consumes the most fossil fuels and generates the largest portion of greenhouse gasses, I will address this issue first. In the past eleven years, the U.S. overall demand for electricity has been rising at approximately 2% a year—well beyond the increase in electricity generated by renewable energy sources. Without the U.S. adopting conservation methods for stabilizing or actually reducing our overall demand for electricity, this trend of increased demand for electricity will likely continue.
Currently the fastest growing renewable sources of electricity both in the U.S. and worldwide have been solar and wind energy, while the other renewable sources of electricity in the U.S. have remained relatively stable. Therefore, for the next few decades, these two sources of electricity are the only renewable sources that can be counted on to make up this increase. However, in 2005 these two sources only accounted for less than ½ of a tenth of a percent of all the electricity generated in the U.S. In fact, the total amount generated by these two technologies was less than a tenth of the increase in overall demand from 2004 and 2005. Therefore, without the adoption of energy conservation measures, solar and wind energy will not be able to grow fast enough for the U.S. to avoid having to build additional fossil fuel based electrical generating plants. In fact, if the U.S.’s demand for electricity is not checked by conservation measures, it will be approximately 2025 before the annual growth in solar and wind electrical generating capacity will be large enough to absorb the increase in overall electrical demand. By that time, the U.S. will have to build possibly as many as 250 new fossil fueled 1000 Megawatt power plants, most of whom will be built before carbon sequestration systems have been proven technically viable.
Unfortunately, these new plants will remain in operation for another 30–50 years, continuing to spew thousands of tons of CO2 each day into the atmosphere. Obviously, the best solution is, as quickly as possible, to adopt measures for reducing our overall demand for electricity via conservation measures in order to minimize the number of new power plants that will be needed before the growth in capacity for solar and wind generated electricity can be expected to deal with expected increases in overall electrical demand and then to start replacing existing, aging fossil fuel power plants which are responsible for much of the air pollution impacting Americans now.
As far as bio-ethanol potential for addressing the energy needs for the transportation sector, again the current total bio-ethanol production capacity is just barely equal to the annual increase in gasoline consumption, which has averaged approximately 1.5% over the first five years of this century. Even with a bio-ethanol production of 3,000 billion gallons in 2010, as projected by one source, this would only replace less than 2% of the gasoline consumption as extrapolated from our current usage and the 1.5% rise per year—that is unless the U.S. also adopts measures for reducing our usage of gasoline. Furthermore, the 3,000 billion gallons projected to be produced in 2006 is slightly less than half the gallons of gasoline that would be saved today if the overall fuel efficiency for all vehicles in the U.S. merely increased by an average one mile per gallon. Whether such an increase in fuel efficiency will occur as the result of mandated miles per gallon standards, such were proposed by the state of California, or as the result of consumer decisions based upon higher gasoline prices is still an open question. However, it is clear that bio-ethanol, by itself, will have only a minor effect on reducing the greenhouse emissions from transportation over the rest of this decade. It is also clear that the only means to make major reductions in greenhouse gas emissions from transportation will be through conservation measures such as through mass transit systems that will reduce the average miles each American drives each year, by increasing the average miles per gallon that the average vehicle gets, and other such changes.
In summary, currently, bio-ethanol as well as the generating of electricity from solar and wind energy currently are making a very minor dent in our use of fossil fuels and generation of greenhouse gases. In the near future conservation is the most effective means of reducing our fossil fuel usage and the generation of greenhouse gases. In fact, without conservation methods, the U.S. may even need as many as 250 new, large fossil fuel power plants before the annual increase in our demand for electricity can be met by the annual increase in electricity generated from solar and wind energy.
by Tom Pritchett
Tom teaches Environmental Science at Cedar Crest College and is a member of the Alliance Energy Group