Verfahren zur integrierten Betriebssimulation von Strom- und Gastransportinfrastrukturen

• Integrated dispatch simulation of electricity and gas transport infrastructures

Löhr, Lukas; Moser, Albert (Thesis advisor); Fasold, Hans-Georg (Thesis advisor)

1. Auflage. - Aachen : printproduction M. Wolff GmbH (2022)
Book, Dissertation / PhD Thesis

In: Aachener Beiträge zur Energieversorgung 221
Page(s)/Article-Nr.: x, 217 Seiten : Illustrationen, Diagramme, Karten

Dissertation, RWTH Aachen University, 2022

Abstract

In the context of the European Green Deal, the European Commission has formulated a strategy for energy system integration. Its goal is to create integrated energy infrastructures with increased physical coupling of the electricity, hydrogen, methane and district heating infrastructures. These are to be planned and operated in a supply-secure manner with the lowest possible emissions and costs. The bidirectional coupling of the transmission systems for electricity and gases forms the backbone of integrated energy infrastructures. In order to leverage optimization potentials, the introduction of an integrated system planning is being discussed. Within such a process, dispatch simulations are needed for the calculation of assessment parameters such as welfare gains, CO2 emissions or grid security indicators. Therefore, the aim of this work is to develop a method that has a high temporal, spatial and technical resolution in an integrated modeling approach, while allowing applicability to large-scale systems. The developed method is based on a nonlinear optimization problem, which minimizes variable operating costs, CO2 emissions and energy not served during plant dispatch and network operation of the electricity, gas and district heating infrastructure. The transport infrastructures for electricity and gases are modeled on grid-node level, considering quasi-steady-state physical power flow equations for the calculation of grid congestion and grid losses. The scalability of the method allows the application to large-scale energy systems over an entire year in hourly resolution. To control model complexity, a three-stage nested decomposition approach is developed. This solves the optimization problem several times, first with a high level of model detail in temporal, then spatial and finally technical dimension. Thereby, several model reduction techniques are applied and information is propagated at the interfaces of the different stages. The nonlinear optimization problem is solved in the last stage with successive linear programming. In exemplary investigations, the performance of the developed method is demonstrated. To this end, it is applied to a scenario of the European electricity, hydrogen, methane and district heating system in 2040. The application shows cross-infrastructure interactions in operation, which represent the optimized system responses to surpluses and shortages of renewable electricity generation, grid congestion in the electricity and hydrogen transmission system or shortages of seasonal hydrogen storage capacities. In a cost-benefit analysis of electrolyser sites in Germany, it is presented that primarily grid congestion and secondarily grid losses in the electric transmission system influence the siting decision and outweigh congestion and losses in the hydrogen system. Electrolysers close to renewable electricity generation from wind turbines in northern Germany therefore have a greater systemic benefit than electrolysers close to load centers in southwestern Germany.