Analysis of Net Zero-energy Building in Spain. Integration of PV, Solar Domestic Hot Water and Air-conditioning Systems

In this work, global energy balances for grid-connected Spanish buildings have been carried out to evaluate the potential of self- consumption applying European Directives. Using the software TRNBuild, five three-story buildings have been created and run in TRNSYS Simulation Studio. Four end-user categories (hospitals, offices, shopping center, schools) and five Spanish provinces with different weather conditions have been selected to calculate total thermal, electrical and domestic hot water (DHW) consumptions. It was assumed thermal (heating and cooling) and DHW demands could be supplied without direct consumption of fossil fuels, using air-to-air heat pumps and solar collectors with electric auxiliary resistances. Hence, for each case, a global electrical balance (discounting solar thermal contribution) between demands and the PV array production has been performed. Finally, parametric and economic analyses have been carried out, demonstrating the feasibility of these systems.