Energy Efficiency Trends in Large Clusters of Residential Buildings
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Master Level Thesis Energy Efficient Built Environment No.11, Jun 2019 Energy efficiency trends in large clusters of residential buildings Master thesis 15 credits, 2019 Energy Efficient Built Environment Author: Viktor Unéus Supervisor: Mats Rönnelid Examiner: Ewa Wäckelgård Dalarna University Course Code: EG3020 Energy Engineering Examination date: 2019-06-04 K i Abstract The aim of this thesis work is to analyse the trends in heat use among Borlänge Energis district heating customer over the last 20 years. Several reports show that in general the buildings stock get more and more efficient, both in Sweden and other European countries, but will the same trend be seen among Borlänge Energis customer? Data of delivered heat to 324 customers, both single-family houses and multi-family houses, for the period of 1998-2018 is used in this study. The heating that is assumed for domestic hot water is calculated and the heat used for heating is temperature corrected so the heat needed for a normal year could be calculated. The investigated customers are divided into different groups representing various types of buildings with different building years. From this data it’s possible to see trends in heat usage in kWh/building, and year for various types of buildings over the period. Other studies on how trends for heating usage in buildings have report heating usage in kWh/(m2,year). It wasn’t possible in this work to get data of the size of each building, which means that it’s not possible to compare the result from this study with other studies. However, assuming that the building area have been the same and that no extensions of the buildings have been done during the period, the trend in changed heat use should be the same, unless the result is presented in kWh/m2, year and kWh/building, year. The overall results show that there is a reduction in energy use in the buildings in Borlänge during the period 1998-2018. The decrease in heat use are in the order of 0.3 – 0.4 %/year, with larger decrease in multi-family houses. This is considerably less than the decrease of heat use in the buildings stock of 0.9 – 1.2 %/year reported for the entire building stock in Sweden during approximately the same period. ii Contents 1 Introduction ................................................................................................................................... 1 Aims and Objectives ............................................................................................................. 1 2 Literature Review........................................................................................................................... 2 3 Theory and data anlysis ................................................................................................................ 4 Availed data ............................................................................................................................ 4 Personal integrity ................................................................................................................... 4 Balance temperature .............................................................................................................. 4 Temperature correction ........................................................................................................ 4 Hot water ................................................................................................................................ 5 Energy signature .................................................................................................................... 6 Heating reader ........................................................................................................................ 6 Energy cost ............................................................................................................................. 6 Disposable income ................................................................................................................ 7 Single family house prices .................................................................................................. 7 Sample size ........................................................................................................................... 7 Investigater areas ................................................................................................................. 7 4 Method .......................................................................................................................................... 10 Need of heating per building ............................................................................................. 10 Calculation ............................................................................................................................ 10 Margin of error in the calculations .................................................................................... 11 5 Results ........................................................................................................................................... 13 Need of heating .................................................................................................................... 13 Energy signature .................................................................................................................. 18 Sensitivity analysis ................................................................................................................ 18 5.3.1. Change of DHW share ............................................................................................... 19 5.3.2. Change to constant DHW ......................................................................................... 19 5.3.3. Conclusion ................................................................................................................... 20 5.3.4. Change balance temperature ..................................................................................... 20 6 Discussion .................................................................................................................................... 21 7 Conclusions .................................................................................................................................. 23 Limitations and/or Applicability of the Study ................................................................ 23 Recommendations for Future Work ................................................................................. 23 Acknowledgment ............................................................................................................................ 23 8 References .................................................................................................................................... 24 Appendix 1, Energy signature .......................................................................................................... i iii Abbreviations Abbreviation Description DH District heating DHW Domestic hot water SMHI Swedish meteorological and hydrological Institute iv Nomenclature Symbol Description Unit D Date Dend End date for the period in question Dstart Start date for the period in question DD Degree day °C/day Haverage Average heating MWh Hcorrecteed Temperature corrected heating usage MWh HDHW,average The average heating for DHW MWh HDHW, day Heat for DHW and day MWh HDHW Heat for DHW in the period MWh Hend End of the heating trend MWh HStart Start of the heating trend MWh k Constant for DHW n Numbers of days in the month x year xchange Yearly change % v 1 Introduction In this thesis work together with Borlänge Energi (The local energy company) and Sweco the task is to analyse the trends among the district heating (DH) customers need of heating. Borlänge Energi has 6 534 DH connections including 5 695 single-family households and 784 connections for companies where multi-family houses includes [1]. This thesis work will focus on single and multi-family houses. While Borlänge Energi has data back until 1998 saved, they haven’t analysed how the energy need among their customers has change over time. Since the data from each customer needs to be processed before it can be used, 345 DH connections has been chosen which will represent different areas. In their data it’s possible to know if it’s a private or company customer where multi-family households used to be owned by companies. In Table 1 the heat sources for the DH network in Borlänge under 2017 is listed [2]. As can be seen household waste, biomass and waste heat from the industri accounts for a large part of the total heat delivered to the customer. The emissions from DH is specified to 68 CO2- eq/kWh for combustion and 4 CO2-eq/kWh for transport and production of the fuels. A majority of this emissions is coming from burning the waste. Table 1, fuel for DH in Borlänge 2017 Fuel Share Waste heat from the industry 20.4 % Smoke condensation 1.5 % Net heat from heatpumps 0.5 % Houshold w aste 39.3 % Landfill and sewage gas 0.6 % Bio fuel 34.7 % Electricity to heatpumps, electricity boiler etc 1.8 % Fossil fuel 0.5 % Other 0.7 % While there are some old buildings being replaced by new ones most of the buildings that we will use in the coming decades are already built. In 2018 there were 2 081 112 single-family houses in Sweden which is an increase of 63 048 single-family houses over the last three years [3]. During the same period there were 146 618 newly houses built which means that 83570 or 4.1 % of the