Integrated Electricity and Gas Systems Modelling: Assessing the Impacts of Electrification of Residential Heating in Victoria

Electricity and gas systems are undergoing a fast transition towards low-carbon and more integrated energy systems. One of those pathways is the electrification of residential heating, whose impacts can be better quantified by jointly modeling the two systems. This paper presents a novel integrated electricity and gas transmission system model with high spatiotemporal resolution and realistic system operating constraints. The electricity system model is a unit commitment with a strengthened DC optimal power flow, formulated as a mixed-integer linear program. The gas network model consists of a dynamic gas flow model that captures gas network flexibility, as measured by the linepack. The model is implemented on projected 2025 case studies with the actual Victorian transmission systems, assuming the use of air-to-water electric heat pumps for both space heating and domestic hot water. In the context of the specific assumptions and scenarios considered, results suggest that: (i) residential electrification will generally require additional imports and/or local generation, and interconnectors and intra-state transmission lines may also need augmentation in scenarios with full electrification; (ii) the gas network can provide the flexibility needed by the system in most electrification cases; and (iii) the total electricity-gas CO
₂
emissions might slightly increase as electrification increases.