District heating has the potential to provide consumers with heat using resources that would otherwise be wasted (e.g. surplus heat from industry) or increase overall efficiency by generating both heat and electricity. However, the introduction and utilisation of district heating has to be performed in a responsible way in order to benefit all the different stakeholders involved. A positive outcome depends on local preconditions and the identification of trade-offs involving different environmental, social and economic considerations. In the history of district heating, several illustrative articulations of sustainability can be found, and situations in which different trade-offs have become clear.
This chapter will discuss some articulations of sustainability and the environmental, social and economic trade-offs that can be identified for district heat distribution systems, to help achieve a deeper understanding of sustainability considerations and trade-offs for technical systems in general. Examples from research on district heating, carried out at Chalmers University of Technology from 1991 until today, will be used to illustrate real-world dilemmas.