Abstract
This paper considers a solar combined heat and power (CHP) system comprising parabolic trough collectors, a backup boiler, and an organic Rankine cycle engine. Its application is especially analysed in the context of a district heating and cooling network with a temperature of 20-30 °C, where distributed heat pumps are used as user substations. The case of a high temperature traditional network is however also considered. The analysis includes TRNSYS simulations for different geographical locations and different variants of the system configuration. Technical performances are presented in terms of energy outputs, which are then used for economic estimates. A similar analysis is carried out also for a flat plate collector field for heating only, in order to compare different possible ways of exploiting the solar resource. The solar-CHP configuration is found to yield acceptable economic performances, provided an extensive use of the backup boiler is considered. Environmental implications and alternative solutions are discussed.