The Sunday, July 2, edition of the Washington Post had a column titled "The False Hope of Biofuels" which had the basic premise that biofuels could only supply half of our transportation fuel needs by 2025 and that food supplies would be compromised if it did so. I don't think that any responsible person has argued that we could supply more than 30% of our current transportation fuel requirements, rather a diversity of fuels and conservation methods, featuring plug-in hybrid electric vehicles, will be required to provide relief from our increasingly expensive oil supplies.
In the most authoritative report on this subject "Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply", an ORNL study determined that enough fuel could be produced from biomass to meet more than one-third of our current demand for transportation fuels in the U.S. by 2030. As far as the arguments about land usage, the land necessary for producing the biofuels includes currently unused marginal land on which switchgrass or similar crops could be grown, land that is currently idle, and cellulose products produced from forestry wastes and the like, that do not require any additional land usage, as well as a fraction of the land currently devoted to the production of food, which is currently used to produce food for export or to produce food that is bought by the government to subsidise farmers. This study did not include the very significant amount of fuel that could be made from municiple solid waste, or methane from landfills and animal wastes (manure).
The answer to our increasingly expensive fuels is a diversified utilization of several technologies, not just biofuels. The combination of biofuels; vehicles that use less fuels, such as energy efficient hybrid electric vehicles (HEVs): those made by Toyota, the Honda Insight and Civic and the Ford Escape
Escalade; more importantly plug-in hybrid electric vehicles (PHEVs); all electric vehicles (EVs); fuels made by coal liquefaction; vehicles running on CNG; our remaining domestic supplies of oil; and gains in efficiency made possible by more widespread use of mass transportation are more than sufficient to supply our transportation needs for the foreseeable future, even after allowing for population growth and land needed for growing food crops.
In the long run biofuels would only be needed for some specialty vehicles, perhaps such as airplanes or some military vehicles, that are difficult to transition into one of the other categories or whose performance is greatly reduced by these other methods and to supply the fuel needed to run the PHEVs. PHEVs and EVs eventually could be the mainstay of our personal transportation fleet. Use of these two types of vehicles transfers the primary source of energy from oil to electricity, which can be made from renewables (preferably), coal, or nuclear sources.
Suitable battery technology has been the limitation that has prevented the marketing of PHEVs and EVs, the engineering of these vehicles is relatively straight forward, given a suitable battery. Suitable batteries (lithium ion batteries made by A123 and Altair, several other companies have batteries in earlier stages of development. Kokam (South Korea) has been furnishing lithium ion batteries for limited production PHEVs such as taxis being developed by Hybrid Technologies) have been developed and are being tested. Problems with overheating have been overcome. These batteries are lightweight, have a high energy density, a long operating life, can be charged rapidly and have a suitable operating temperature range to be used in light vehicles. The obstacles are further testing, cost and production volume. Testing is proceeding satisfactorily and should be complete this year. Cost is said to be a function of production volume and maturity of the products. Most experts agree that suitable batteries will be available in two to four years. DaimlarChrysler has a test fleet of 20 PHEV vans and both Toyota, GM and Ford have disclosed that they are developing PHEVs. A Toyota Prius has been modified to a plug-in by Energy CS , earlier post, by replacing the standard 1.3 kWh NiMH batteries with a 9kWh Lithium-ion battery pack.
Significantly greater yields are being made every year as to the amount of ethanol or biodiesel that can be made from an acre of feedstock and the net positive energy available from a unit of fuel is also constantly increasing as the processes and land useage become more efficient. Admittedly ethanol made from corn is a poor source; this is merely a transitional supply as technologies are being developed (and have already been demonstrated) to make ethanol from the whole corn plant (kernels plus corn stover) and virtually any feedstock that is made of cellulose.
There are other biofuels such as those being developed by Dupont the University of Wisconsin and biodiesel made from algae is being seriously developed by three US firms. Dupont and BP will begin marketing the first generation of biobutanol in the UK in 2007. Biobutanol is touted as a better fuel than ethanol, it has a higher energy content and it can be used in engines without any modifications.
All of these fuels and vehicle technologies do not consider the usage of the fuel cell in transportation vehicles. Fuel cells still have many technological and cost barriers that must be overcome before they can be used in light transportation vehicles (cars, SUVs, vans and pickup trucks). Very expensive fuel cells with a short lifetime and without a fuel (hydrogen) distribution infrastructure may be available in 4 or 5 years, but most experts believe it will be 20 or more years before they come into widespread use and therefore the fuels and technologies described earlier are needed and probably superior to fuel cells. The National Research Council recently concluded, “Overall, although a transition to hydrogen could greatly transform the U.S. energy system in the long run, the impacts on oil imports and CO2 emissions are likely to be minor over the next 25 years.”