When Will Alt-Fuels Replace Diesel, Gas Powered School Buses?

When Will Alt-Fuels Replace Diesel, Gas Powered School Buses?

Innovation in the school bus and medium-truck market is moving forward at a very rapid pace. The technological advances of new propane, CNG and electric school buses promise enhanced performance, improved fuel efficiency and reduced impacts to the environment. But districts and contractors will be hesitant to purchase such vehicles unless the following prove to be true: Grants and funding remain available to offset costs of vehicles, fueling and facility infrastructure; cost differential is narrowed; fuel tax credits remain in place; and the required fuel is readily available in their market at affordable prices and able to be on site. 

Manufacturers are increasingly interested in developing vehicles powered by electricity, natural gas, propane, and fuel cells, projetcs supported by billions of dollars of investments in research and development. But which technology will win the hearts of the school bus industry and transform the transportation sector of tomorrow? 

Without coordination between the vehicle, fueling and battery charging industries, successful market introduction of these new systems will be characterized by starts and stops, booms and busts and a prolonged (and potentially economically painful) market development phase that may or may not result in school bus sector acceptance. An example is the anecdotal evidence voiced by operators frustrated by the maintenance and operation of the post-2007 diesel exhaust emissions reduction systems that is driving much of the interest in alternative fuels.

Decision-makers in vehicle sales and manufacturing must join  power train systems developers and fuel suppliers in understanding how the school bus market will mix new technology with the challenges of maintaining its legacy fleet. Also, what adjustments must be made by the operator as regulatory issues develop and change, this will provide the ultimate value to the consumer?

Will Natural Gas, Propane or Electric replace Diesel and Gasoline? 

Recently, much attention has been raised concerning the rise of natural gas, propane systems and all-electric drivetrains as a domestically sourced and clean school bus transportation fuel, as vocal advocates for electric, natural gas and propane urge the transition of the school bus to run on those fuel systems. 

However, at present the CNG, Liquefied Propane and electric penetration in the school bus sector is about 5 percent. Many energy experts, presidential councils, and federal and state energy authorities all conclude that diesel will remain the predominant powertrain in North America and will remain the primary transportation fuel for the long term. This is attributable to the inherent energy density of diesel fuel and the ability of the diesel engine to translate the energy content into power economically. 

Supported by improved diesel exhaust after treatment systems developed to clean diesel emissions never imagined 20 years ago, diesel will probably remain the primary power plant choice for the next decade. Based on current school bus sales trends alternative fuels such as CNG and LNG, and innovative battery-electric school buses could increase to 10- to 15 percent of the total school bus market by 2020. Not surprisingly, Cummins has recently announced it is implementing an electrified powertrain program.

While alternative fuel proponents have aggressively pushed the claims of cleaner air with electric, CNG and LP, diesel engine manufacturers have not sat idle. New innovations in diesel engine design and after-treatment devices have virtually eliminated particulate matter and nitrogen oxides, and new vehicle performance enhancements have helped lower measurable carbon dioxide, successfully meeting the lowering of the targeted pollutants of the phased-in EPA diesel emissions reduction ruling. 

The comparison of old diesel to new CNG, LP and electric needs to stop. The market is changing, slowly. School bus operators seem to be more open to alternatives than ever before for a variety of reasons, not the least of which is economics and the environment. STN recently received 170 responses to a survey on alternative-fuel adoption. But in response to the question, “Do you operate alternative fuel buses,” only 36 readers responding, “Yes.” These also represented slightly more than 100 buses. Meanwhile 60 percent of those said they have received funding grants to offset the price of the bus, with 66 percent purchasing propane, 28 percent CNG and 6 percent electric. 

Hurdles must continue to be cleared for any of the competing alternatives to successfully gain market share. These include the reduction of vehicle cost, conveniently available refueling infrastructure, expanded vehicle comparable mpg range, overall user familiarity with the product, and confidence in the safety and reliability of the new technology. These obstacles can be overcome in time, and already we are seeing the incremental costs coming down. They will continue to do so, as the engine and vehicle OEMs enhance their R&D but it will require strategies spanning multiple industries to ensure that the operator realizes the full benefit of the new technologies. 

School bus operators need to assess the overall impact on the life-cycle cost, including setting reserves for their future replacement when switching to alternative fuels. Ultimately the operator will determine what fuels and vehicles will dominate the market of the future. What is clear today is that their choices are becoming more varied. From the alternative fuel vehicle options now available, to better performing diesel vehicles, consumers have choices to make going forward on how to invest their money and how to shape the future. 


TL PudlewskiBob1Pudlewski is STN’s technical editor with more than 40 years of experience in the school bus industry. He is the retired vice president of fleet operations, procurement and maintenance for Laidlaw and is a member of the National School Transportation Association Hall of Fame. 





Reprinted from the April 2017 issue of School Transportation News magazine.