Beräkning av koldioxidutsläppet från bostadssektorn i Stockholms län
During the last decades the housing sector has increased continuously, and housings and services accounted for 40 % of the energy usage in Sweden during 2011. The expansion in number of buildings in society has resulted in an increase in both energy usage and emissions of greenhouse gases. It is crucial to enable a sustainable development of society and as a result, the demand to reduce the emissions of carbon dioxide is a current question. In this study, the carbon dioxide emitted from the housing sector in Stockholm is estimated. The housing sector can be divided into different types of houses such as apartment blocks, single-family houses and holiday houses. By collecting information of the energy purchased in respective households, a computational model is generated that calculates the total emission of carbon dioxide. The computational model is created in Excel and based on various assumptions and boundaries regarding the production of electricity and district heating. The environmental impact of the energy purchased is studied through a lifecycle perspective and the energy statistics is studied through an average perspective. The model is designed to calculate the emission factor from the electricity production through a Swedish, Nordic and Northern European perspective. The model also generates a value of the emission factor for the district heating system in Stockholm. By combining the emission factors and the energy statistics, a value of the total emission of carbon dioxide from the housing sector is obtained. A case study is implemented by examining the energy usage for the year of 2010. The emission of carbon dioxide during the year was approximately 1.3 million tones. By taking the import of electricity into account in the Swedish perspective, the result was obtained.When the Swedish electricity mix was replaced with the European mix, the amount of carbon dioxide increased approximately 3 times. As a result of the cold climate and low production due to recession during 2010, limited flow in water reservoirs and low production in nuclear power plants the emissions was approximately 30 000 tonnes higher compared to the year before. By assuming a Swedish electricity mix, the case study shows that the emission per square meter is the highest in apartment blocks, while the emissions from the single-family houses and holiday houses are relatively low in comparison. According to the sensitivity analysis the emission is essentially affected by the import of electricity. The efficiency in power plants also affects the result of the electricity mix in the Nordic and Northern European perspective. However, the selection of electricity mix in the production of district heating, biomass fuel in single-family houses and efficiency in boilers and burners are practically insignificant in the final result.