Multi-objective optimisation of a solar district heating network with seasonal storage for conditions in cities of southern Chile

Abstract

Rapid urban growth and enhanced quality of life have significantly increased the demands for indoor heating, especially in the developing world. In Chile, this demand is provided largely through low quality biomass which creates pollution problems. Due to the medium to high solar resource in most of Chile, solar thermal networks with seasonal thermal storage should be considered. In this paper, we assessed the use of solar energy with seasonal thermal energy storage to provide domestic heating through a heat network. For this, we performed a simulation-based multi-objective optimisation of the system’s design with cost and greenhouse gas emissions as objectives for two locations in Chile. Our results show that solar thermal networks are cost-competitive with conventional alternatives. Furthermore, the inclusion of seasonal thermal storage could improve the system performance decreasing the emissions by around 90% while increasing the LCOE by less than 20% compared with a conventional gas-heated network or resistive electric heating. We found that for specific system configurations and locations solar district heating with long term storage could be cost-competitive with burning firewood if externalities such as the social costs of local pollution were considered in the economic analysis.