Environ-economic analysis of high-temperature steam electrolysis for decentralized hydrogen production

Abstract

Hydrogen has attracted attention as a sustainable energy source that can replace fossil fuels because it does not emit CO2 during combustion. Water electrolysis can be used to generate "green hydrogen;" however, electricity prices determine the cost competitiveness of water electrolysis. Moreover, small-scale production is necessary owing to the difficulties in terms of the transport and storage of hydrogen. Thus, we propose a decentralized hydrogen production method using an integrated model of a solid oxide electrolyzer cell (SOEC) and a small modular reactor (SMR). A comparative study was also conducted for different configurations of the integrated model considering the carbon emission costs. The results indicate that when both electricity and heat are supplied from an SMR to the SOEC plant, the hydrogen production cost ranges from $5.02 to $7.60 per kg of H2, whereas the CO2 emission is the least at 0.36 kg per kg of H2. Our findings suggest that the integrated model is both feasible and sustainable for decentralized hydrogen production.