Performance of factory made solar heating systems according to standard ISO 9459-5:2007

Abstract The utilization of solar energy based technologies has attracted increased interest in recent times in order to satisfy the energy demands in buildings. This research work presents a comparative analysis of the energy production and costs of factory made solar heating systems, Thermosiphon Solar Water Heaters Systems (TSWHS) and Forced-circulation Solar Water Heaters Systems (FSWHS), as a function of profile type (high and low) and collector absorber treatment (selective and black painting). We observe that the energy performance and the Levelized Cost of Energy (LCOE) is similar in TSWHS and FSWHS for load volumes below tank nominal volume, black painting absorbers and locations with high solar irradiation. In the case of load volumes greater than nominal, climates with low irradiation and collectors with selective absorbers, the differences in their energy performance can reach a 7% and the LCOE can increase up to 9%. The LCOE is lower for TSWHS systems for all the evaluated scenarios. We have also found that for cold climates, the FSWHS systems present higher net annual energy produced, however, for warm climates TSWHS systems present greater net annual energy production.