Optimal hydrogen infrastructure planning for heat decarbonisation

Energy decarbonisation is essential to achieve Net-Zero emissions goal by 2050. Consequently, investments in alternative low-carbon pathways and energy carriers for the heat sector are required. In this study, we propose an optimisation framework for the transition of heat sector in Great Britain focusing on hydrogen infrastructure decisions. A spatially-explicit mixed-integer linear programming (MILP) evolution model is developed to minimise the total system's cost considering investment and operational decisions. The optimisation framework incorporates both long-term planning horizon of 5-year steps from 2035 to 2050 and typical days with hourly resolution. Aiming to alleviate the computational effort of such multiscale model, two hierarchical solution approaches are suggested that result in computational time reduction. From the optimisation results, it is shown that the installation of gas reforming hydrogen production technologies with CCS and biomass gasification with CCS can provide a cost-effective strategy achieving decarbonisation goal. What-if analysis is conducted to demonstrate further insights for future hydrogen infrastructure investments. Results indicate that, as cost is highly dependent on natural gas price, Water Electrolysis capacity increases significantly when gas price rises. Moreover, the introduction of carbon tax policy can lead to lower CO2 net emissions.