Small district heating systems - System alternatives and costs

The interest for central heat supply of small residential areas using renewable energies (e.g. biofuels) is increasing in Sweden. Furthermore, many houses in detached residential areas are heated with electricity. Governmental aims to reduce the use of electricity motivate to discuss the possibility to connect those houses to a central heat supply. In this context distribution heat losses, the house substation's efficiency and the efficiency of the house heating system are regarded as being important performance parameters. Studies in the field usually focus on one or two subsystems at a time. In this study an overall approach on the distribution system, the house substation and the space heating system in the building is applied, i.e. all parts are regarded as one system. The objective is to identify, from an economical point of view, the optimal system design and operation strategy for the central heat supply of a small residential area.