Fourth-Generation District Heating and Motivation Tariffs

Future district heating systems and technologies—also known as fourth-generation district heating—have a potentially important role to play in the green transition of societies. The implementation of fourth-generation district heating involves adjustments in the demand side to allow for low temperature supply. In order to facilitate such changes, district heating supply companies have in recent years introduced tariffs with penalties for high return temperatures and benefits for low return temperatures. This paper describes the case of a housing community of 17 buildings in their attempts to adjust to such tariffs as an integrated part of connecting to district heating. Replacing domestic hot water tanks with instantaneous heat exchangers and introducing smart meters resulted in abilities to lower the return temperature from around 40 °C to around 30 °C. However, the current design of the motivation tariffs does not yet fully compensate the consumers because the supply company provides unnecessarily high supply temperatures. Based on such efforts, this paper discusses the fairness and effectiveness of the tariffs and provides recommendations for improving them.