A general model for the optimization of energy supply systems of buildings

The model has been applied to a case study consisting of a domestic building located in Bilbao (Northern Spain). 13 different technologies were taken under consideration together with the specific conditions of the Spanish context. Three different objectives were determined: (i) the optimal cost; (ii) the Zero Energy Building (ZEB); and (iii) the ZEB′, an alternative ZEB where the whole electricity consumption is considered for the calculation of the NRPE. The 3 cases were compared and analyzed and, finally, a parametric evaluation was carried out, setting the aspects that limit the feasibility of low energy buildings: economic feasibility and physical constraints such as roof availability for renewables.