Evaluating the sustainability of the hydrogen economy using multi-criteria decision-making analysis in Korea

South Korea announced a hydrogen economy roadmap and hydrogen regulations aligned with its decarbonization plan. However, the environmental, economic, and social sustainability of the hydrogen economy in South Korea has not been thoroughly studied. Under the Energy Trilemma framework, we compared the positive and negative impacts of hydrogen with other energy carriers, including nuclear, coal, gas, and renewables. The selected evaluation criteria included the energy return on energy investment, greenhouse gas emissions, levelized cost of electricity, import dependency, and long-term energy storage. As a result, we argue that green hydrogen improves environmental sustainability and energy security by reducing the carbon emission intensity of the energy sector and energy dependency on imported sources. We propose three critical policy implications to maximize the benefits of hydrogen while minimizing its negative economic impact. First, the rapid expansion of renewables, particularly large-scale wind power, is required. Second, clean hydrogen portfolio standards must be aligned with South Korea's decarbonization plan. Third, governmental investment in research and development activities and demonstration projects will reduce hydrogen production costs by maximizing the utilization of renewable resources.