Life Cycle Assessment of Different Low-Temperature District Heating Development Scenarios: A Case Study of Municipality in Latvia

Sustainable heating solutions involving renewable energy sources and low supply/return temperatures for district heating are evolving. Low temperature use in district heating allows reducing the heating operation costs significantly and at the same time holding the sustainability criteria. However, an in-depth study on environmental impacts during the life cycle of low temperature district heating was not conducted until now. Thus, this study aims to find the best development scenarios for development of local low temperature district heating. For this purpose, a methodology adopts life cycle analysis approach that allows assessing the environmental impacts according to a variety of environmental performance criterions. The results of the study showed an improvement in the overall environmental performance towards the transition of a conventional 3^rd generation district heating to low temperature concept including the effects of reconstruction and modernization of the boiler house. A set of potential development is proposed. Specifically, the scenario implementing low temperature district heating with solar PV showed the best score for environmental performance. The scenario with implementation of low temperature district heating without solar PV did not show significant improvement in environmental performance under operation conditions of a pilot case study.