After an exhaustive analysis and with multiple alternative transportation fuel options considered, hydrocarbon-based fuels are expected to remain the predominant energy source driving American vehicles come 2050, according to a report by the National Petroleum Council.

The study, “Advancing Technologies for America’s Transportation Future,” sought to advise the U.S Department of Energy on fuels, technologies, industry practices and government policies for transportation in an effort to increase fuel efficiencies and reduce greenhouse gas emissions. In addition to petroleum, the report delved into the likelihood of biofuels, natural gas, electricity and hydrogen as commercial alternatives for advanced-fuel systems.

Commissioned two years ago by Secretary of Energy Stephen Chu, the study found that while alternative transportation fuels can become commercially viable in the coming decades, significant technology and infrastructure barriers exist and will require dedicated economic investment and some scientific serendipity to overcome.

“Transportation in the U.S. is undergoing dramatic changes. These changes could evolve at an accelerated rate dependent on the speed of technology advancements and the economic viability of alternative fuels and vehicles,” the report said.

But barring an unforeseen technological breakthrough, “internal combustion engines will remain dominant because of their lower cost and use in a diverse set of vehicle platforms." Based on commerciality, future vehicles will look technologically much like what is already in production or being developed today: conventional gasoline and diesel liquid, hybrid electric, plug-in hybrids and compressed natural-gas propelled.

The study identified 12 technology hurdles that would need to be overcome before wide-scale commercialization of advanced fuel systems could occur.
As an alternate to petroleum, natural gas as a transportation fuel held a clear advantage. This is due primarily to ease of conversion as natural gas vehicles benefit from nearly identical power trains and vehicle structure. Challenges include vehicle price premiums and infrastructure availability.

“The availability of long-term, low-cost domestic sources of natural gas, driven by significant new sources of shale gas, may present an opportunity to increase the role of natural gas as a transportation fuel,” according to the report. “Natural gas fueled vehicles could play a significant role in both light duty and heavy duty fleets if the cost differential between natural gas and oil persists, and natural gas vehicle costs significantly decrease through increased production and scale.”

However, the study notes that while liquefied natural gas and compressed natural gas are cost-competitive options for heavy-duty trucks, “diesel will remain the primary fuel” in 2050, the report projects.

Advanced biofuels could gain significant share in light-duty vehicles, concludes the study, but only if technology, cost and scale challenges can be overcome.

Alternative fuel options like electricity and hydrogen are not likely to have a material impact on medium and heavy duty fleets, but “could find use in niche applications.” The viability of electric vehicles depends upon discovering new battery chemistry to extend the range of the car and life of the battery. Advanced storage options are needed to boost hydrogen.

Alternative hydrocarbon liquids — gas-to-liquid (GTL), coal-to-liquid (CTL) — will require higher oil prices than currently forecast to gain traction. Still, these represent a large potential resource that could augment petroleum supply. “Commercial production of methanol from natural gas is established, but unlike GTL and other liquids significant investment would be needed in fueling and vehicle infrastructure.”

Bob Greco, director of downstream and industry operations for the American Petroleum Institute, responded in a release, “This report underscores the importance of an all-of-the-above energy strategy for America that includes responsible development of our vast oil and natural gas resources.”

The U.S. oil and natural gas industry has invested $71 billion in technologies aimed at reducing greenhouse gas emissions, Greco pointed out, compared with $43 billion by the federal government.

The future transportation fuels study makes no effort to calculate costs, but does recommend the government promote sustained funding of technologies while remaining market neutral. It also suggests government assist state, local and private governments as well as special interest groups to streamline the permitting and regulatory process for infrastructure.

“In the years ahead, the U.S. transportation sector could have access to a broad array of economically competitive fuel-vehicle system options…If the technology and infrastructure barriers can be overcome, plug-in hybrid, fuel cell, battery electric and natural gas powered passenger vehicles and heavy duty vehicles could come into widespread national use over the coming decades.” But, the scale of this effort “will be enormous,” the researchers forecast.

“Internal combustion engine technologies are likely to be the dominant propulsion systems for decades to come, with liquid fuel blends continuing to play a significant—but reduced—role.”

To access the report, click here.