Life Cycle Assessment of Natural Gas-Powered Personal Mobility Options

The recent expansion of unconventional natural gas production in the United States has enabled a steady increase of its use in all consumption sectors, including transportation. In this study, the environmental footprints of three natural gas-based personal mobility options are examined from a life cycle perspective: battery electric vehicles (BEVs), compressed natural gas vehicles (CNGVs), and fuel cell vehicles (FCVs). The results suggest that natural gas-powered vehicles have the potential to considerably reduce the overall environmental impact associated with driven miles in comparison to conventional petroleum-powered internal combustion engine vehicles (PICVs). BEVs and FCVs in particular offer significant reductions in greenhouse gas emissions, especially if carbon capture and sequestration (CCS) technologies are implemented at the fuel conversion facilities. It was furthermore determined that the use phase dominates the life cycle impacts of all of the vehicles considered, although the manufacture of power sources for BEVs and FCVs significantly contributes to their respective environmental burdens. Efforts presently being exerted for the greener manufacture and more efficient powertrain design of BEVs and FCVs are likely to further extend their environmental advantages over CNGVs for the utilization of natural gas as a transportation energy resource.