Hydrogen economy is a socio-economic system in which the main energy source is hydrogen. To reach net zero emissions by 2050, the hydrogen economy is getting more attention in Seoul as well as Korea. Transition from fossil fuel to hydrogen is also expected to induce the new industry and lower the import dependency. The hydrogen technology is classified into three fields: production, storage-transportation, and utilization. In the utilization, the field of most interest to the public, a fuel cell is the key component. Fuel cell is an electrochemical reactor wherein the hydrogen and oxygen react to produce heat and electricity. A small-size fuel cell is installed in a car to become a fuel cell electric vehicle, while a large-size fuel cell is established as a combined heat and power plant.

Seoul city is increasing its budget for hydrogen economy from 23.6 billion won in 2019 to 60.3 billion won in 2020, focusing on the transportation section. Though it is an early stage of promotion policy, Seoul had a similar experience in the 2000’s: the change of diesel city bus to CNG bus. Because hydrogen and CNG have similar characteristics as a new expensive eco-friendly fuel, the successful transition of 7,000 CNG buses offers good implications. Moreover, as a leading city in the adoption of hydrogen economy, Ulsan also provides many insights with its wide range of policy experiences.

This study sought to estimate the socio-economic effects of the hydrogen economy scenarios in Seoul. The effects of greenhouse gas reduction, particulate matter reduction, and operating revenue of refueling station are calculated as economic benefits. The first policy scenario of operating refueling station and subsidizing hydrogen bus, costs 143.5 billion won with benefit of 33.9 billion won in the most active plan until 2040. The second policy scenario of subsidizing non-commercial hydrogen passenger car costs 604.1 billion won with benefit of 48.1 billion won in the most practical plan until 2040. As a result, we conclude that Seoul city needs to focus on refueling station and bus rather than non-commercial passenger car. For hydrogen economy. Seoul should consider not only the pace of introducing hydrogen technology but also the reliability of its applications.