Energy Systems Simulation on an Urban District-Level

Abstract: The development of urban-scale energy systems modelling on a district-level is presently the target of many research organisations because of the growing interest in assessing the effect of energy efficiency throughout the full energy chain in urban district environments. This Master thesis includes an overview on energy use with aggregation at building- and a geographically restricted residential area level. The research was focused on three aspects to achieve sustainable development: selection of a modelling tool within energy engineering, energy systems modelling on a building-level and on an urban district-level, and an analysis of the magnitude of energy flows (heat and electricity) between different system components and also on an aggregated level on an hourly basis at predefined climate conditions. To reach the objectives, an extensive screening of 129 modelling tools was conducted based on nine different parameters provided in table form. Moreover, a more in-depth literature study was conducted in text form where a total of 21 modelling tools were reviewed addressing a wide range of characteristic features within each tool. The chosen modelling tool was “SimulationX” for this work. Other tools considered were e.g. EnergyPlan, TRNSYS, and Homer. SimulationX was mainly chosen because of the expected high level of detail that could be achieved in the modelling process and the wide range of components available to design an energy system, both on a building-level and on an urban district-level. Furthermore, a design of the requested architecture of the energy system on an urban district-level has been established representing the full energy chain from natural resources to energy end-use services. By the use of the SimulationX software and the Green City library specifically used in this project, a total number of three concepts were created with the general idea to present the difference between individual energy solutions of households compared to integrated solutions of multiple households for a part of a district in the area of Uppsala to emphasise the possible synergistic effects. The first and second concept describe the integrated energy system within a building while the third concept simulated a restricted residential area consisting of 67 single-family houses, 197 terraced houses and 120 dwelling apartments. Based on the results from the simulations the total annual energy demand for electricity and heat was estimated to be 4653 and 11 153 kWh, respectively for a single-family house. For a terraced house, the electricity and heat demand amount to 4000 and 7122 kWh, respectively. On an urban district-level, the model design indicates that the heat demand of 2604 MWh can be sufficiently met throughout the year with a TES integrated in the system, but the total annual electricity supply is 436 MWh lower than the demand. The main advantages with the chosen modelling tool are the predefined parameters and user profiles available as well as the high level of detail that can be achieved on a building-level. However, the tool currently lacks the ability to estimate CO2 emissions and calculate the investment costs required for the different energy system models. For future recommendations, an economic analysis can be conducted to calculate the investment costs required for different energy system designs. This will help future decision-making processes in evaluating the feasibility of an energy system and possibly what components that significantly might affect the total investment costs.