Evolving a Cleaner Grid: Uses of Natural Gas in Transportation

Achieving greenhouse gas emissions reduction goals from the transportation sector will be a monumental challenge. Various alternative vehicle technologies such as plug-in hybrids, battery and fuel cell electric vehicles offer the promise of sharply reducing end use emissions. However, when considering the full fuel cycle, it is clear that a dramatically cleaner electricity grid will also be necessary if we ever hope to meet ambitious long-term reduction goals. To demonstrate the importance of achieving this dramatically cleaner grid, our analysis implements Argonne National Laboratory’s GREET model and the latest Annual Energy Outlook data to evaluate the relative merit of various alternative vehicles on a well-to-wheel basis while taking into account projections for the evolution of the U.S. electricity supply. Fortunately, significant progress is now underway to transform the electricity sector. The emergence of substantial supplies of shale gas, at low cost and substantial abundance, has dramatically reshaped the energy landscape. There are multiple pathways for this abundant supply of natural gas to help reduce the transportation sector emissions footprint, whether through greater utilization in highly efficient natural gas combined-cycle electricity generators, direct use in compressed natural gas vehicles, or steam reformation to provide hydrogen for fuel cell vehicles. Greater reliance on high efficiency natural gas combined cycle generators, combined with the steady expansion of renewable generation and energy efficiency, is providing a critical alternative to continued reliance on dirty, legacy generators. This emerging new clean power paradigm can multiply the benefits of more rapid growth in electric drive vehicles.