ROUSH CleanTech’s Clean School Bus program informs states on the maximum emissions reduction and monetary savings that they could achieve based on the VW Trust funds they allocate to replacing school buses.
In anticipation of the funds states can request from the Volkswagon Environmental Mitigation Trust Fund, Todd Mouw, vice president of sales and marketing, told STN that ROUSH CleanTech has “developed a Clean School Bus program that we are sharing with all state beneficiaries that showcases how much NOx could be reduced in their state depending on the percent of money allocated to school bus replacement.”
This program consists of sending each state that is interested an overview of how ROUSH CleanTech’s propane engines compare to older diesel ones, and the benefits that can be affected when purchasing alternative fuel engines. ROUSH CleanTech offers a worthy option with their 6.8L V10 3V engine which was certified in June by the California Air Resources Board to a NOx emission rate of 0.05 g/bhp.hr, making it 75 percent cleaner than the EPA’s standard of 0.20 g/bhp.hr.
The company provided STN with sample programs for the states of New York and Virginia. These projections are determined with the help of the Alternative Fuel Life-Cycle Environmental and Economic Transportation (AFLEET) Tool, which was developed by Argonne National Laboratory for the Department of Energy's Clean Cities Program.
The information sent to states stresses that replacing diesel school buses with alternatively-fueled ones is especially advantageous because the average life of a school bus is 15 years, meaning that there are diesel buses in operation that do not meet the current emissions standards, which were updated in 2010.
New York has 50,000 school buses in operation daily and in Virginia has over 15,000. In both states, the Clean School Bus program shows that a 2017-model year propane school bus is $5,000 to $10,000 more expensive than a diesel bus of the same model year, but is $20,000 to $25,000 cheaper than a 2017 CNG bus. These numbers are similar at the national level as well. The national averages have electric buses coming in at $300,000, over twice the cost of CNG ones.
If New York used one-quarter, or $32 million, of its allotted VW EMT funding for school buses, the program shows it could purchase 1,185 propane school buses, which would result in a reduction of almost 32 million gallons of diesel fuel over the 15-year life of the buses. Each year, over 300 tons of NOx emissions would be prevented from entering the air, and the “earned value” would be $116 million.
The program reveals that if Virginia replaced a 2007 diesel bus with a new “clean diesel” bus, NOx emissions could be cut by 56 percent. However, replacing a 2007 diesel bus with a new propane bus would reduce NOx emissions by 90 percent.
It goes on to list that the cost-effectiveness of a 2017 diesel school bus is $233 per pound, compared to $156 per pound for a propane bus and $194 per pound for a CNG bus. A 2017 Cummins 6.7 engine running on diesel is projected to emit 313 pounds of NOx over its useful life of 15 years. In the same time span, a propane-fueled engine will emit 67 pounds of NOx and a CNG engine will emit 89.
Propane affords the additional benefit of not requiring expensive and repetitive after-treatment because it burns clean and does not produce particulate matter (PM).
“Our Clean School Bus plans incorporate AFLEET model results based upon the states average cost of school buses (diesel, propane, CNG). Funding levels and the number of older school buses operating in that state are considered when developing a state's plan.” Chelsea Jenkins, ROUSH CleanTech’s executive director of government affairs, told STN.
“The funding covers 1992-2009 model years, so we wanted to be conservative,” Jenkins said, but she added that if older buses were replaced, obviously even greater NOx reduction could be achieved.