Dr. Joungho Park and his team from KIER conducted an economic analysis of water electrolysis for green hydrogen production. They compared alkaline and PEM water electrolysis, suggesting optimal operation strategies. Alkaline water electrolysis is cost-effective but needs stable power, while PEM electrolysis can operate on renewable energy but has higher installation costs. The researchers proposed using the existing power grid to supplement alkaline electrolysis and implementing energy storage systems. By combining renewable energy with backup power, production costs can be reduced. The study also recommended applying electrical overload for PEM systems to improve economic efficiency. In environments with high renewable energy shares, PEM electrolysis is ideal, while a combination of alkaline electrolysis and a carbon-free power grid is suitable elsewhere. The team suggested a tailored hydrogen production combination for Korea using offshore wind and solar power. The research aims to guide investment decisions in building hydrogen production systems.