Bachelor's thesis Joel Schölzel

 

Development of a methodology for the systemic evaluation of urban energy systems

Balancing energy system Copyright: EBC Balancing an urban energy system from the individual elements through the system unit building to a district

As a result of the energy transition the electrical and thermal energy supply changes. Due to the expansion of decentralized generation facilities, the volatility of electricity generation expands. The increased use of current-based heat and cold generators results in couplings between the electrical and thermal energy sector. Consequently, it is no longer sufficient to analyze a building as an isolated energy system. There is a need for acommonsystemic approach, taking into account the interactions of buildings with each other and with the supply network through energy demand and feed.

In the context of this thesis a methodology for the systemic evaluation of urban energy systems with the involvement of the higher energy system is developed. It is an instrument for the monitoring data-based analysis of the interactions in a city district, which arise from the increasing interconnections. At the beginning, the basics for the systemic evaluation of a district will be explained. Afterwards, definitions of various properties of urban energy systems are presented. These include network usability, system suitability, flexibility and environmental compatibility. These properties are assigned to literal-based parameters. Network usability is assigned to those parameters that evaluate the physical load of the network that results from the interactions within the district and at the interface to the higher-level system. Under system suitability the parameters are summarized, which allow an assessment of the behavior of the urban energy system as part of the higher energy system. For the assessment of flexibility, a required flexibility is determined and the use of existing flexibility options is considered. Finally, the environmental compatibility is classified with the emissions caused. The required monitoring data are defined and the developed methodology is implemented as a Python tool. The tool is applied to four sample districts to evaluate the systemic behavior of the districts and to discuss the practicability of the methodology.

The results show that in a network-reactive operation battery storages avoid bottleneck situations in the network and increase self-consumption. However, the battery storage is not fully utilized. CHP and PV systems increase coverage and energy autonomy at different times of the year. The application of the methodology requires a comprehensive and complete database. The methodology is characterized by a modular structure. The thesis lays the foundation for an user-friendly, automated assessment procedure for existing districts.