Carbon mitigation potential of power to gas (P2G) for the industrial sector in South Korea combining top-down and bottom-up approach

As sector coupling technologies such as Power-to-Gas (P2G) gain attention for achieving carbon neutrality, this study provides the first integrated assessment of the carbon mitigation potential of P2G in South Korea's industrial sector, combining top-down estimates of renewable electricity surplus with bottom-up projections of hydrogen demand in industries. Assuming a 3 % reduction allowance rate and that 25 % of the required flexibility infrastructure is provided by P2G facilities, P2G could produce up to 3.63 MtH₂ of hydrogen annually by 2050 through grid-responsive operations. Projected hydrogen demand across steel, petrochemical, and cement sectors is 6.82 MtH₂, with steel accounting for 51 %. If fully supplied by P2G, the potential GHG reduction reaches 110.83 MtCO₂eq, equivalent to 42.5 % of 2018 industrial emissions. The quantitative results reveal a supply–demand gap and varying abatement efficiencies, with hydrogen-based steelmaking offering the highest mitigation per unit. These findings provide insights for sector coupling policies by identifying feasible deployment boundaries and prioritization strategies, emphasizing the alignment of hydrogen deployment with power system capabilities.