Sustainable Transportation Energy Pathways (STEPS)
The focus of this report is on the transportation technologies that can be used to reduce fuel usage. Even though reducing greenhouse gas emissions is the ultimate goal, the structure of the California Energy Futures project was to separate the demand for energy from the supply. Vehicle efficiency is a demand side option while developing low carbon electricity and fuels is a supply side option and each of these is considered separately (there are reports of the availability of biofuels and low-carbon electricity). This report is a supplement to the Summary Report for the California Energy Futures (CCST 2011) and examines the contribution of the transportation sector to California’s total energy demand along with the potential for technologies in different transportation sectors to reduce fuel demand in the year 2050.
If greenhouse gas (GHG) emissions are to be reduced substantially, by as much as 80% by 2050, transportation must play a large role, given that it makes up approximately 40% of greenhouse gas emissions in California. The transportation sector includes light-duty vehicles (passenger cars and light duty trucks), heavy duty trucks, buses, aviation, rail, marine, agriculture and off-road vehicles. The three primary means of reducing transportation emissions are reducing travel demand, reducing energy intensity and reducing carbon intensity. In order to achieve the very deep reductions in emissions necessary to meet the target, advanced technologies will need to be employed both for making vehicles more efficient and for producing low-carbon fuels. The benefit of using of these advanced technologies is, of course, dependent upon the level of adoption of these technologies and the associated reduction in energy use and carbon intensity.
We forecast that total transportation travel demand will continue to grow through 2050 because of population growth and increasing demand per capita, which follows historical trends. This growth will need to be counteracted by significant increases in efficiency, electrification (including hydrogen) of vehicles and use of low-carbon fuels and electricity. The business-as-usual (BAU) scenario in this analysis projects that transportation fuel demand for 2050 will be approximately 43 billion gallons of gasoline equivalent (gge), compared with 2005 values of around 27 billion gge. Both the BAU and the median cases discussed in the summary report assume that the population increases 50% between 2005 and 2050 and per capita light-duty VMT increases by 33% (based upon Caltrans 2008). Implementation of technologies to significantly improve efficiency and deploy electrified transport could lead to transportation fuel demands in 2050 of approximately 17 billion gge, much of which is electricity, hydrogen and biofuels. Reductions in travel demand that occur because of changing development and demographic patterns as well as via policies such as SB 375 could result in even further reductions in fuel use and make the GHG reduction targets easier to achieve.
Suggested citation: Yang, Christopher, Joan Ogden, Dan Sperling and Roland Hwang. California’s Energy Future: Transportation Energy Use in California. California Council on Science and Technology. December 2011.