Hydrogen is a flexible energy carrier and storage medium that can play a critical role in decarbonizing energy and fighting climate change. One major impediment towards wider adoption of hydrogen is the lack of supporting infrastructure, including refueling stations, production plants and distribution facilities. Farsighted policies are required to attract infrastructure investments and create the necessary economies of scale for hydrogen to become market competitive with other sustainable alternatives. This research addresses several critical challenges facing the rollout and scale-up of hydrogen infrastructure in California. An optimization-based modeling approach including technical, economic, social, and environmental factors will be utilized to help design an evolving holistic infrastructure system for hydrogen through 2050. This work will be done collaboratively between the UC Davis Institute of Transportation Studies and the National Renewable Energy Laboratory (NREL), leveraging each other’s expertise across different fields such as the hydrogen supply chain, and electric and natural gas grids. NREL’s Scenario Evaluation & Regional Analysis (SERA) model will be central to this modeling effort, with soft linkages to a suite of other models developed at ITS-Davis. A goal of this analysis is to help formulate hydrogen related policies that would enable California to achieve its carbon neutrality targets by 2045.