Driving Towards Sustainability?An Assessment of Smith College’s Vehicle FleetNora Beem – EVS 300 – Spring 2005Abstract:The recent formation of a sustainability committee at Smith College speaks to thegrowing awareness and need to make environmentally conscious decisions regarding theCollege. One area in which changes could be made to reduce the College’sEnvironmental footprint is transportation. Converting the 20 diesel vehicles to a B20biodiesel is one way to reduce both emissions and consumption of fossil fuels. Using aB20 blend eliminates the need to retrofit the current engines. Another way in which theCollege could reduce fuel usage and the consequent emissions would be to replaceseveral of the 7-passenger vans and sedans with hybrid vehicles. The economicsassociated with converting to biodiesel are negligible considering the benefits the Collegewould gain in emissions reductions as well as how the decision would reflect on thesustainability of the campus. Projections for converting several of the gasoline vehiclesto hybrids show that in several instances the hybrids cost less overall as well as use lessfuel. These findings support the notion that the College can make choices that are bothenvironmentally and economically beneficial. Reducing the emissions caused by Smithtransportation would not only reduce our footprint, but also reinforce the College’s claimof seeking more sustainable options on campus.Introduction:Cars have become the trademark of American society. They are a status symbol, acultural icon. Unfortunately, this love affair has become one of the leading contributors to greenhouse gas emissions worldwide. In 1995, it was estimated that there were roughly 777 million vehicles (cars, trucks, and motorbikes) in the world (McNeill 2000). Another source estimates that approximately 44 million motor vehicles are sold each year(Gabel). With one vehicle for roughly every eight people, it is not surprising that global warming is progressing at an increasingly rapid rate. According to the Environmental Protection Agency (EPA), the average car expels approximately 11,500 pounds of carbon dioxide annually, while trucks produce over 16,000 pounds (“Consumer”). The United States produces more greenhouse gases per capita than any other country in the world. It is estimated that 6.6 tons of greenhouse gases are emitted annually for each US citizen (“Global”). While certainly not the most powerful greenhouse gas in terms of ability to trap heat, carbon dioxide is by far the largest productof the combustion of fossil fuels. In average vehicle emissions, the carbon dioxide produced is twenty times greater than the carbon monoxide produced, 150 times greater than the hydrocarbons, and 300 times greater than the nitrogen oxides emitted. Carbon dioxide illustrates a positive correlation with fuel consumption; every one percent increase in fuel consumption results in a one percent increase in carbon dioxide emissions. The EPA credits this greenhouse gas as transportation’s primary contribution to climate change (“Consumer”). In fact, every gallon of gasoline burned produces over 24pounds of carbon dioxide as a waste product and diesel fuel generates nearly 28 pounds per gallon (“Emissions”).The state of Massachusetts alone produced 98.4 million metric tons of carbon dioxide emissions in 2002, with transportation contributing to more than 30 percent of this greenhouse gas. The University of Massachusetts, Amherst campus, based here in Pioneer Valley, was the second highest contributor of carbon dioxide overall (transportation and stationary), producing almost 10 percent of the state’s total emissions – the equivalent of approximately 20,500 cars (Massachusetts). The overwhelming generation of waste products from the combustion of fossil fuels has lead to a search for alternative fuel sources in an attempt to reduce emissions. One of the primary focuses of this search is biodiesel. Biodiesel is an alternative fuel created from renewable resources such as fat or vegetable oil. The majority of biodiesel is generated from soybeans because of the industry’s ability to produce them in excess, but it can also be made from recycled cooking grease (“Alternative”). The fat or oil undergoes a process known as ‘transesterfication,’ whereby it is combined with alcohol and a catalyst to remove the glycerin. The fat/oil separated from the glycerin is then considered biodiesel or methyl ester. The glycerin byproduct is often sold for use in soaps or other products, making the process void of waste (“Biodiesel”). Biodiesel can be mixed in any ratio with petroleum diesel to create a biodiesel blend. However, 41 percent of all biodiesel is a 20 percent biodiesel blend (B20) and another 40 percent is pure biodiesel, or B100 (“Comprehensive”). The attraction of B20 is that it can be used in a regular diesel engine without the need for any modifications or retrofitting. Pure biodiesel, on the other hand, acts as a solvent, and can release deposits of previous petroleum diesel, causing the fuel filter to clog. This complication often requires the commitment to biodiesel from the beginning of the vehicle’s life (“Clean”).There is a strong correlation between biodiesel and fossil fuel emissions. As the percentage of biodiesel increases, there is a steady decrease in the amount of carbon monoxide, hydrocarbons, and particulate matter produced (“Comprehensive”; fig 1). While itis true that the amount of nitrogen oxides increases slightly with the percentage of biodiesel (fig. 1), this is due to the higher density and lower volatility of biodiesel in comparison with petroleum diesel. It is thought that these differences advance the fuel’s injection and subsequent combustion, causing higher nitrogen oxide emissions (“Evaluation”). The benefits of biodiesel are clear – not only does its use lessen the production of greenhouse gases, but the renewable fuel reduces our dependence on nonrenewable fossilfuels. The absence of this fuel being used on a commercial scale leads one to believe thatthere might be a drawback, and there is – an economic one. It takes approximately 7.3 pounds of soybean oil to produce one gallon of pure biodiesel. With soybean oil costing about 20 cents per pound, that comes out to $1.50