The demand for a cleaner, greener environment is evident. Seems like everyone –from small communities to large corporations–is doing their part these days to promote a safer and cleaner environment, changing the way they operate to positively impact the preservation of the earth. School districts look to make their communities cleaner, and one way is through the use of alternative fuel in their school buses. The benefits of using alternative fuel in school buses are three-fold: in some cases it’s cleaner for the students and the environment, it may positively impact maintenance of the buses, and it offers potential cost savings to the district and community.
While alternative fuels may be eco-friendly, there are still several unknowns and a lot to learn about the various types of alternative fuels available and how to determine which fuel is best suited for your fleet and operation. Schools districts across the U.S. and Canada are working to understand the big picture as technology, infrastructure, and policy surrounding alternative fuels evolve. First Student is positioned to support the multiple options available and help the school districts in the implementation and management of the various options.
Compressed Natural Gas (CNG)
CNG is a fossil fuel substitute for gas and diesel. One of its attractive qualities, in addition to significantly reducing emissions, is the great supply of natural gas resources in the US and Canada. CNG is non-toxic, dissipates quickly, and its higher ignition temperature reduces the chances of accidental ignition. According to Clean Energy, the largest provider of natural gas fuel for transportation in North America, natural gas can provide savings as well as reduce NVH (noise, vibration, and harshness) as compared to other fossil fuel power plants. Reduced noise means fewer distractions for the bus driver.
Propane is a clean-burning fuel that reportedly reduces greenhouse gas, nitrogen oxide, carbon monoxide and total hydrocarbon emissions. Propane’s lower carbon content makes it more environmentally friendly than other fossil fuels, and it’s not harmful to soil or water. Additionally, propane dissipates into the air, has a narrow flammability range and is non-toxic and non-poisonous. The fuel is produced domestically from natural gas processing and crude oil refining and is easily available due to its abundant supply.
“There is certainly a growing trend towards alternative fuels from both an environmental and a fuel cost perspective, Mario DiFoggio, manager of Center for Education and Marketing for Thomas Built Buses, says. “Propane autogas has become particularly popular in the pupil transportation industry, however compressed natural gas (CNG) is also gaining traction in certain pockets of the country where infrastructure is in place to support this fuel choice.”
Diesel, traditionally, the most commonly used fuel in school buses, has suffered bad press due to Particulate matter emissions (black smoke). However, diesel fuel has improved considerably in the past few years. Clean diesel is a cleaner burning fuel that works in conjunction with particulate filters designed to clean diesel exhaust fumes and soot before they leave the vehicle’s exhaust system.. Diesel fuel now boasts lower levels of emissions and improved fuel economy. In fact, all buses manufactured since 2010 utilizes what the industry terms “clean diesel,” using ultra-low sulfur diesel fuel, catalysts, diesel exhaust fluid (DEF), particulate matter filters, and performance parts including vg turbos, and high-pressure common rail with injection pressures approaching 20,000 psi, to achieve a very eco-friendly power plant that challenges all clean fuel alternatives .
In 2003, the EPA launched a Clean School Bus USA program aimed at reducing the amount of pollution created by diesel school buses. The EPA estimates that more than 45,000 buses are using emission-reduction technologies and cleaner fuels
Choosing the fuel that best suits your school district’s needs may depend on a few factors, such as the availability of certain types of buses in your fuel choice, training in the use of alternative fuel, handling and storage of the fuel, Duty Cycle, and costs involved in developing an infrastructure or modifying existing facilities to support your fuel choice. “We believe that each district has its own unique circumstances that ultimately dictate the right fuel selection for their total cost of ownership,” DiFoggio says.
To better understand the technology, visit the U.S. Department of Energy Website, which provides plenty of resources and educational tools about alternative fuels. Also available is the Clean Cities Alternative Fuel Price Report, which provides detailed information and comparisons about the prices of alternative and conventional fuels.