Hossein Hesamzadeh in his Ph.D. thesis seeks to improve the operation and economic design of district heating and cooling systems within local energy communities. His research is motivated by the need to support decarbonization, sector coupling, and the integration of distributed energy resources, while addressing the technical, economic, and regulatory challenges arising from coupled thermal and electrical networks and the strategic behavior of participating actors. In this context, his work examines how such systems can be designed, operated, and regulated to ensure technical feasibility, economic efficiency, and fairness, while enabling effective participation in local energy and flexibility markets. The outcome of the thesis will be  the development of innovative modeling and decision-support frameworks, together with policy-relevant insights on pricing mechanisms and regulatory structures, to improve system performance, economic sustainability, and community participation, thereby contributing to more resilient, efficient, and low-carbon local energy systems.