Hydrogen Blending in Iberian Gas-Electricity Networks using Mixed Integer Linear Programming

J. Laguna Domínguez, F.A. Campos

Summary:

This paper develops an hourly optimization model coupling hydrogen (H₂) and natural-gas (NG) transport with electricity dispatch through combined-cycle gas turbines (CCGT). Mixed gas nonlinearities are approximated using McCormick relaxations and a tangent-based pressure-flow approximation. An iterative concentration reconstruction and bound-refinement procedure reduces the mixing inconsistencies, while fixed flow directions and relaxed thermal commitments make the weekly management tractable. A 2030 Iberian case study compares hydrogen mass-fraction limits from zero to 2.8% during a representative week. H₂ utilization ranges from nearly 0% to 85.7%, showing that H₂ injection potential strongly depends on project location, downstream gas demand, available NG dilution and network flow and pressure constraints. Increasing the maximum H₂ mass fraction from 0.7% to 2.8% raises avoided direct CO₂ emissions from 4.08 to 17.88 kt. The impact on CCGT generation is comparatively small, while gas composition, flows and pressures are more significantly affected.

Spanish layman's summary:

Modelo horario de optimización entera que acopla redes de H₂ y GN con el despacho eléctrico mediante CCGT. El caso ibérico 2030 muestra que el potencial de inyección de H₂ depende de la ubicación, demanda, dilución disponible y restricciones de flujo y presión, con reducción de CO₂.

English layman's summary:

Hourly integer optimization model coupling H₂ and NG networks with electricity dispatch through CCGTs. A 2030 Iberian case shows that H₂ injection potential depends on location, demand, dilution and flow/pressure constraints, while higher H₂ blending substantially reduces direct CO₂ emissions.

Keywords: H2 blending, gas-electricity coupling, integer programming, McCormick relaxation, Iberian energy system

Registration date: 29-sep-2026