Suggested Citation:
Allan, Alexander (2011) Renewable Transportation Fuel for California’s Electric-Drive Vehicles. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-11-20

California has enacted a number of policies that incentivize the use of advanced vehicle technologies and fuels to help reduce petroleum usage, air pollution and greenhouse gas emissions. These include the Pavley greenhouse gas emissions standards, the Low Carbon Fuel Standard (LCFS), the Zero Emission Vehicle (ZEV) and Low-Emission Vehicle (LEV) regulations and initiatives that support adoption of alternative fuels, such as the Air Quality Improvement Program (AQIP) and Alternative Fuel Incentive Program (AFIP). In addition, the state has set an economy-wide goal of reducing greenhouse gas (GHG) emissions 80% below 1990 levels by 2050. Greatly reducing GHG emissions from the transportation sector will likely require large-scale adoption of electric-drive – plug-in hybrid electric, battery-electric, or hydrogen fuel cell vehicles – powered by renewable, low carbon electricity or hydrogen. Under the Renewable Portfolio Standard (RPS) the contribution of renewable sources to California's electricity generation mix will increase from 20 percent in 2010 to 33 percent in 2020. Likewise, SB1505 requires hydrogen transportation fuel in California to achieve a 30% reduction in GHG emissions per mile and include a 33% renewable component. The mutual policy goals of decarbonized transportation fuels and electricity generation will lead to a “convergence” of these two previously disparate energy sectors. Any effort to assess California’s ability to achieve deep GHG emissions cuts from transportation will therefore require an integrated approach that considers such a convergence, understanding how best to share energy supply resources among both sectors and meet the combined demand for low carbon, renewable energy they represent.

In previous studies, Ryan McCarthy developed an hourly model of California’s future electricity grid (LEDGE-CA) to investigate GHG emissions and cost impacts attributable to interactions between growing populations of electric-drive vehicles and the evolution of the electricity supply in California. This thesis aims to extend McCarthy’s work in two key areas: quantifying renewable resources available for electricity and hydrogen fuel production in California and investigating the potential role of energy storage. Using geospatial and temporal analysis of planned and potential renewable electricity generation projects, this study develops a detailed assessment of the hourly renewable electricity supply in California that serves as an input into LEDGE-CA. Wind and solar energy are abundant renewable resources in California, yet their intermittency make them challenging to integrate into the electricity grid. Grid-energy storage options are evaluated to investigate how best to utilize wind and solar energy resources to meet electricity and hydrogen fuel demand.

This study assesses the total potential for using renewable resources to produce fuel for electric and hydrogen vehicles in California and identifies potential strategy differences in terms of where and when to produce electricity and hydrogen fuels. Alternative pathways are compared with respect to cost, GHG emissions, energy demand, and transition issues.