Time: Wednesday, 04/Sept/2024: 11:00am - 12:00pm Session Chair: Stephanie Riedmüller |
Location: Theresianum 0601 Room Location at NavigaTUM |
Long-term multi-objective optimization for integrated unit commitment and investment planning for district heating networks
Zuse Institute Berlin, Germany
The need to decarbonize the energy system has led to an intensified focus on district heating networks in urban and suburban areas. Therefore, exploring transformation pathways with reasonable trade-offs between economic viability and environmental goals became necessary.
We introduce a novel network-flow-based model class integrating unit commitment and long-term investment planning for district heating networks incorporating multi-energy markets. While the integration of unit commitment and investment planning has been studied for electrical and multi-energy systems, suitability for the application of long-term portfolio planning of a single district heating provider on an urban scale has yet to be met. Based on mixed integer linear programming, the model bridges the gap between overly detailed industrial modeling tools not designed for computational efficiency at scale and rather abstract academic models.
The formulation is tested on Berlin's district heating network, including potential investments with a 25-year depreciation period. Hence, the challenge lies in the large number of variables and constraints and the coupling of time steps through investment decisions.
A case study explores different solutions on the Pareto front defined by optimal trade-offs between minimizing costs and CO2 emissions through a lexicographic optimization approach, i.e., optimal costs are relaxed incrementally before prioritizing CO2 emission reduction.
The resulting solution catalog can provide decision-makers valuable insights into feasible transformation pathways, highlighting distinctions between robust and target-dependent investments. This study's findings further emphasize the significance of integrating unit commitment into investment planning to provide a nuanced understanding of possible ways to decarbonize district heating.
Costs for transition of the heat sector in a large city: simulation of scenarios with a digital twin
1IU International University of Applied Sciences; 2Stadtwerke München GmbH
A functioning transition of the heat sector is a prerequisite for the success of the energy transition as a whole. Against this backdrop, Germany has set itself the target of using only renewable energies and unavoidable waste heat in the heat sector by 2045 at the latest. For this purpose, among other measures, the Heat Planning Act was created, which regulates the development of municipal heat plans. The Stadtwerke München (SWM) have developed the ‘Model Munich’, a building-specific geographic information system containing data on heat demand, heating system, construction year etc., which is coupled with the multi-agent system Invert/EE-Lab. This enables the simulation of building-specific long-term scenarios regarding renovation rates and depths, as well as the selection of systems for space heating and hot water generation. The ‘Model Munich’ in combination with the multi-agent simulation model Invert/EE-Lab was used by the city of Munich to develop a municipal heat plan. The simulations of long-term scenarios for the transition of the heat sector consider building-specific investment and operating costs. For example, this allows the quantification of the additional costs associated with higher renovation rates and depths needed to achieve the goals of the Heat Planning Act. Furthermore, analyses can be made regarding the effects of higher carbon prices or changes in subsidies.