Impact of global warming and building renovation on the heat demand and district heating capacity: Case of the city of Riga

Changes in weather conditions due to global warming affect the energy demand of buildings, resulting in changes in the installed heat capacity of district heating systems. The study provides a methodology for assessing the potential effects of climate change in combination with renovation of existing building stock on building heat demand. The system dynamics approach was used for investigation of the interlinkages and causality of energy efficiency, global warming, and total installed heat source capacity. Variations in the heating load of a district heating system due to improvements in building energy efficiency were studied in combination with three climate change scenarios. The optimal balance point between investment at the heat source side and at the heat consumers side was also investigated. The interaction of global warming, building heat demand and installed capacity of the district heating system was identified by the levelized investment approach. The study shows that global warming directly influences the heating degree-days and reduces the heat demand in the case study considered (part of the Riga city). A significantly higher impact on heat demand could be achieved by implementation of building renovation, however the funding available for this purpose is insufficient in the studied case.