Energy modeling for eco-cities with focus on energy utilization in built environment

Sammanfattning: This study focuses on residential buildings that are planned to be constructed in the Sino-Swedish project in Wuxi, China. The focus is on how different heat transfer coefficients for building materials affect the energy consumption for a building in terms of heating and cooling requirements.   In the introduction an overview of major energy policies is given as well as a foundation for residential energy efficiency improvements and a description of the key components in other ecocities. A baseline and two scenarios with different energy performance were created in the modeling software DesignBuilder to calculate the energy consumption for heating and cooling. It resulted in three levels of energy consumption were the baseline had an energy consumption for heating and cooling of 62 kWh/m2-year, first scenario had 57 kWh/m2-year and the second scenario had 35 kWh/m2-year. There is a significant difference in energy performance between baseline and scenario two and this is due to the difference in construction air tightness and heat transfer coefficient for windows, walls, roofs, doors and floors.   The results from modeling in DesignBuilder were exported to the modeling software STELLA and scaled up to city level. Three building stock composition scenarios were created; 100 percent baseline, 100 percent scenario two and the last city composition 50 percent baseline, 30 percent scenario one and 20 percent scenario two. The result for each of the building stock scenarios was 126 GWh/year, 87 GWh/year and 116 GWh/year.   The thesis also discuss what parameters that have a significant impact on the buildings energy performance and what assumptions that might affect the results. The building performance and the choice of materials for the building envelope will affect the overall energy consumption; hence have a large impact on the Sino-Swedish eco-city project. The difference in energy consumption between the baseline and scenario two is substantial and the choice will affect other energy systems in the eco-city.