UC Davis Institute of Transportation Studies

Station availability is a major concern when the deployment of an alternative fuel such as hydrogen is considered. Too few stations will make the network inconvenient, while too many will make the refueling network cost prohibitive. As a follow-up analysis to two station siting analyses completed by the authors for the California Hydrogen Highway Network, this report takes a closer look at the regional differences between the four main metropolitan areas in California: Greater Los Angeles, the San Francisco Bay Area, the Sacramento metropolitan area, and the San Diego metropolitan area. The purpose of this analysis is twofold: to generate a general model to assess hydrogen needs in different regions, and to apply the model to compare its results with the California hydrogen highways report. In the analysis that follows, average driving time to the nearest station (convenience metric) is used to determine the number of stations necessary for each region. By using convenience to determine the share of stations, regions that are less dense will be served as well as those regions with high density. The results suggest that the percentage of stations needed to meet a convenience target differs among regions depending on density. For example, a 4-min average travel time in Sacramento requires 7.2% of stations, whereas it requires only 3.3% of stations in Los Angeles. The developed equation predicts station needs as a function of population density and a desired level of convenience; if the caveats explained in the paper are observed, the prediction equation can be applied to any region.