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Alternative fuel sources?
In the state-of-the Union speech President Bush trumpeted the virtues of ethanol - a domestically produced biomass – corn, soybeans, sunflower -based environmentally friendly alternative to petrol. Ethanol, an alcohol based fuel, can power ‘flex-fuel’ cars that run on either petrol or alcohol. Heavily supported by federal subsidies the production of ethanol (driven largely by electoral politics in Mid Western states) has risen from virtually zero in 1980 to an estimated 4 billion gallons in 2005, according to the Renewable Fuels Association. This is still a drop in the ocean (1%) when compared to daily petrol consumption of 375 million gallons. The main constraint to the greater penetration of ethanol-based fuel is its price despite millions of dollars of state subsidies. Importantly, research from Cornell University has shown that turning plants such as corn into fuel uses much more energy than the resulting ethanol generates. The report by David Pimentel and Tad W. Patzek at Berkeley, published in Natural Resource Research (Vol. 14:1 65-67) found that:
• Corn required 29 percent more fossil energy than the fuel produced
• Switch grass requires 45 per cent more fossil energy than the fuel produced; and
• Wood biomass requires 57 per cent more fossil energy than the fuel produced.
However, President Bush wants a vast expansion of the ethanol industry, particularly for “cellulosic ethanol”. Cellulosic ethanol is prepared using advanced technology and does not rely on valuable crops as it can use straw, corn stalks or agriculture debris. However, in spite of advances this process reportedly still has some way to go before becoming at least as competitive as currently used methods of ethanol production.
The Fuel Cell
The fuel cell is extolled as another one of the solutions to America’s oil import dependency. In January 2003 President Bush announced a plan to spend hundreds of millions of dollars to develop the fuel cell. A fuel cell is a machine – a devise that converts a fuel such as hydrogen to electricity without burning it. It uses the electrochemical process rather than the combustion process. The rhetoric and claims about the potential of the fuel cell to revolutionise transport are often exaggerated. The history of the fuel cell dates over 50 years and technologies under development for decades do not typically enjoy breakthrough status overnight. In transport, the fuel cell has seen limited use outside of the US space programme.
It is estimated that the current fuel cell engines in cars cost over a hundred thousand dollars each. This indicates how far this technology still needs to progress to be commercially viable. Indeed the fuel cell is no panacea. The hydrogen used in the electrochemical process to generate electricity to power the car currently comes from scarce and depleting fossil fuels like natural gas, oil and coal. Moreover while the electrochemical process in the car engine is non-polluting, the initial generation of hydrogen in the factory comes from a process called ‘reforming’, which does generate pollution or carbon dioxide (CO2) emissions. Thus, while hydrogen is relatively abundant in the environment (water, air etc), it still remains a huge challenge to produce it in a form that can be utilised in the electrochemical process, in a non-polluting and cost effective way.
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