Petroleum Displacement And Greenhouse Gas Reduction
While it may not be of major concern to racers right now, one final and extremely important factor to consider is the environmental impact provided by this project. Currently, nearly all race fuel comes from the same source that's used in our day to day transportation. This fuel source is pumped out of the ground from wells, processed, and shipped-either by truck or pipelines-to the local fueling stations. We then purchase the fuel, burn it in our car, and fill it back up when empty.
Summarizing earlier articles, the United States currently consumes approximately 20 million barrels of oil per day, 365 days a year, approximately 65 percent of which is imported. This rate is one quarter of the world's total consumption. To put this in perspective, if one were to take the number of 55-gallon drums of petroleum the U.S. consumes in a single day and place them side by side along Interstate 40, the line of drums would stretch from the West Coast all the way to the East Coast, back to the West Coast and then back east to Amarillo, Texas. Since this source is non-renewable and has a limit, there will come a time in which the transition to other energy sources must occur.
Petroleum displacement is defined as the amount of petroleum that can be substituted by another energy source. The total amount of petroleum used by transportation includes the amount used to produce and transport the fuel, known as "well-to-tank." The amount used to propel a vehicle (or race car) is called "tank-to-wheels." The sum of these is the "well-to-wheels" petroleum consumption number.
To reduce the petroleum used on a well-to-tank basis, its concentration in fuel can be reduced. For this project, E85 was the fuel chosen. By doing so, the team effectively replaced 85 percent of the petroleum-based fuel with a renewable fuel (ethanol). Note that in the processing of E85 some petroluem is consumed on the well-to-tank basis, therefore the reduction is not exactly a one-to-one relationship. Even so, in a 30-lap race with the car averaging 5 mpg, less than 1 gallon of petroleum would be consumed in an E85-fueled engine.
Another issue is global climate change. The largest contributor of greenhouse gases from transportation is carbon dioxide (CO2). The total amount of CO2 from vehicles is the sum of the CO2 generated in making the fuel, well-to-tank CO2 plus the amount generated from tank-to-wheel. This is defined as well-to-wheel CO2. Since petroleum is pumped out of the ground, processed and burned, there are no upstream factors reducing the total amount formed. However, if the fuel used comes from a renewable source that requires atmospheric CO2 to grow, the total well-to-wheel carbon footprint may be greatly reduced.
To fully evaluate energy emission impacts of advanced vehicle technologies and new transportation fuels, the fuel cycle from wells to wheels and the vehicle cycle through material recovery and vehicle disposal need to be considered. Sponsored by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE), Argonne has developed a full life-cycle model called GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation). It allows researchers and analysts to evaluate various vehicle and fuel combinations on a full fuel-cycle/vehicle-cycle basis.(www.transportation.anl.gov/modeling_simulation/GREET/)
In the case of cellulosic E85, 85 percent of the fuel comes from natural biomass that absorbs atmospheric CO2, and grows through the process of photosynthesis. This greatly reduces the well-to-wheel carbon footprint. Using Argonne's GREET model along with data collected from the track, CT's team analyzed the total well-to-wheel carbon footprint of the Camaro, using both petroleum-based race fuel and cellulosic ethanol. For cellulosic ethanol, our analysis used switch grass as feedstock and included corn-based ethanol, race fuel, and modern production vehicles for comparison.
The results from this well-to-wheel analysis are startling. By switching to corn-based E85, a race team would lower greenhouse gas emissions by 25 percent. If it used a cellulosic blend of E85, the race car would have a lower greenhouse gas impact than an unleaded-fueled, '10 Toyota Camry. If it used a 100 percent blend of ethanol (E100), the car would have a lower greenhouse gas impact than an unleaded-fueled Toyota Prius! In fact, the race car would exhibit a greenhouse gas impact of a vehicle that ran on unleaded fuel, achieving 115 mpg. In addition, using E85, over a 30-lap race (including two warm-up laps), only one gallon of non-renewable fuel would have been consumed. Using E100, not a single drop of petroleum would be used. Domestically-generated money spent on fueling the vehicle would stay in the U.S., supporting local industry. That's a win for everyone involved.