Abstract:Currently, hydrogen is used in California in only a few significant applications, with refining being the most dominant. However, hydrogen has the potential to be a major zero-carbon energy carrier across many applications, including transportation, buildings, and various industries. What would be required for this kind of scale-up? What is the potential for hydrogen in different sectors and in different parts of the state? How can this potential be realized? Scaling up the use of hydrogen will likely require strong policies because currently it is produced on a small scale and is therefore expensive. This brief covers basic concepts of how hydrogen could be used, and how much end-use demand potential there could be for different applications across transportation, buildings and industry; however, it should be noted that this brief does not consider hydrogen used within the electricity system). It also considers strategy to some degree – such as where the greatest efforts should be placed. It builds on research that is ongoing on UC campuses as well as other sources.