Potential for Energy Efficiency Improvement Beyond the Light-Duty-Vehicle Sector

The Transportation Energy Futures (TEF) Study evaluates various technological, fuel substitution, and policy options for reducing transportation-related greenhouse gas (GHG) emissions and petroleum use. In 2009, 30 quadrillion Btu of energy were used in the transportation sector. Light-duty vehicles (LDVs), cars and light trucks, account for 55% of this energy use. The other 45% consists of freight and passenger transportation by way of medium- and heavy-duty trucks, buses, aircraft, marine vessels, trains, pipeline, and off-road equipment. These are the non-light-duty vehicle (non-LDV) transportation modes. While there has been considerable research focusing on energy efficiency and fuel substitution options for LDVs, much less attention has been given to non-LDV modes, even though they constitute close to half of the energy used in the transportation sector. An extensive literature review of the non-LDV modes was conducted, and this report brings together the salient findings concerning future energy efficiency options in the time period up to 2050. The studies reviewed provided potential energy savings for individual technologies within each mode, as well as an overall energy savings representing the case where all possible improvements are implemented. The overall mode improvement estimate accounts for mutually exclusive technologies and the possibility that some technologies may counteract the effects of others. In addition, the report discusses the projected activity increases in each of the modes and combine this with forecasts of overall energy efficiency improvement potential to estimate the total GHG emissions relative to current levels and to a “business as usual” case based on Annual Energy Outlook (AEO) 2011 projections. The report find that there is room for technological and operational improvements in energy efficiency for each non-LDV mode. However, energy savings due to these improvements are essentially nullified by projected increases in the volume of activity by the U.S. Energy Information Administration and the Federal Aviation Administration, leaving non-LDV energy use and GHG emissions unchanged from 2010 levels. Considerable improvements will be necessary just to maintain the energy consumption and emission status quo. In order to decrease GHG emissions below 2010 levels, levers such as activity reduction, mode shift, demand reduction, and fuel substitution would need to be implemented in parallel with technological and operational energy efficiency measures. Other reports in the TEF series will address these areas.