Comparison of solar thermal systems with storage: From building to neighbourhood scale

Abstract

The temporal fluctuation of solar energy resources often require the utilization of thermal energy storage to increase the level of solar energy. Solar energy systems that are used to meet the heating demands of buildings can be implemented in a variety of system configurations, ranging from energy production and storage at the building-level, to centrally located production and storage components coupled with a district-heating network. In this paper, quasi-steady state simulation models are used to evaluate the impact that different design configurations of decentralized and centralized solar thermal systems (with short- and long-term storage) have on the overall economic cost of the energy provision and the degree of solar energy utilization. A suburban neighbourhood in Switzerland consisting of 11 buildings is selected as a case study. Simulation results suggest that building-level long-term storage configurations out perform all other system configurations in terms of solar fraction and system efficiencies for the given case study. Furthermore, the results demonstrate that the location of the thermal storage and the separation of short- and long-term storage are crucial issues that affect the performance of building-level renewable energy sources, and thus merit further investigation.