Interdependencies in infrastructure investment decisions in multi-energy systems

The German climate protection goals demand the decarbonization of the heating and cooling sector. The scenarios predict a strong electrification of the heating sector, including the substitution of gas-based heating systems. The continued operation of the existing natural gas grids in the case of a decrease in demand could increase energy-related network costs and thus grid charges, which would further increase the attractiveness of electric-based heating systems. An effect that could trigger or foster the gas phase-out. In this thesis, network analysis, multi-agent and mixed-integer linear optimization models are introduced to analyse the business dynamics between the retrofit decisions of building owners and the investment decisions of gas and electricity distribution network operators. The results forecast a decrease in natural gas demand in the gas distribution grids for most scenarios in Germany. In certain configurations, this develops into a self-reinforcing feedback loop that fosters a strong electrification and triggers the defection from the gas grid in the long run.