Dynamic exergy analysis of energy systems for a social dwelling and exergy based system improvement

•Exergy analyses of five energy concepts for a social dwelling are presented.•Two reference energy schemes and three more innovative schemes are evaluated.•Exergy performance of system components are based on dynamic simulations.•Exergy approach is used to further improve the best system configuration.•Adapted configurations have resulted in a further reduction of net PE need.

This paper presents a study of the usefulness of the exergy approach in the development of energy systems for the built environment. The energy and exergy performance of five different energy systems for a social dwelling in a multifamily building from 1960s in Bilbao (Spain) are studied; two reference cases as well as three improved options. The total energy chain is considered from the energy demand to the energy resources and the analyses are performed using dynamic simulations. The exergy losses of energy system components are identified and quantified and efficiency values in terms of energy and exergy are evaluated. Based on an analysis of the exergy losses further improvements are investigated. This study has shown the exergy concept to be a useful addition to the energy concept, giving a more rational analysis than an analysis solely based on the energy concept. It has also shown that identification and quantification of exergy losses can support the further improvement of energy system configurations, leading to a further reduction of exergy losses and thus a further reduction of high quality energy use.