PART I of II
The transportation sector has entered a period of dynamic change. For roughly a century, we have propelled ourselves with internal combustion engines that burn liquid fossil fuels. At present we are evaluating a menu of fuel choices to drive us into the future, including propane, electricity, hydrogen fuel cells, and natural gas.
When contemplating the future of transportation, it can be helpful to think about our original transition from horses to motor vehicles. Between 1890 and 1915 we experimented with many means of propulsion, including steam-driven vehicles such as the Stanley Steamer, battery-electric vehicles like the Becker Electric, as well as vehicles that burned liquid fuels in internal combustion engines like Ford’s Model T.
We are entering a similar period of change, and we would do well to use the fuel that offers the best financial and environmental benefits for each application. There is no “one-size-fits-all” solution when it comes to transitioning our transportation sector from gasoline and Diesel to cleaner fuels.
What are the Options?
- Propane is compelling because existing vehicles may be easily retrofitted to accommodate this low-cost fuel. While propane is cost-effective, it does not offer meaningful Greenhouse Gas reductions over gasoline and Diesel.
- Electricity has distinct advantages insofar as electric propulsion is extremely clean, very efficient, and quite cost-competitive. In this way, battery-electric propulsion is a perfect solution for passenger vehicles and light-duty trucks and buses. Recent experience, however, has shown that battery-electric technology is not reliable or cost-effective for medium- and heavy-duty applications.
- Hydrogen fuel cells are attractive because their exhaust consists of steam. At present, however, hydrogen fuel cells are not cost-competitive, and fuel is difficult to find outside of Southern California.
- Conventional Natural Gas (CNG) and Renewable Natural Gas (RNG) offer a good solution for medium- and heavy-duty fleets that return to base on a daily basis, such as transit, refuse, and cement fleets. CNG and RNG may also work well for log and drayage trucks.