Obtaining a NZEB in Mediterranean climate by using only on-site renewable energy: Is it a realistic goal?

A new concept of building is represented by Zero Energy Buildings (ZEBs). This paper evaluates the possibility to obtain a NZEB (for office building) by using only “on-site” renewable energy, solely on the roof. A dynamic energy simulation code, EnergyPlus, is used. Two different Italian climatic zones (Palermo and Naples) and two typologies of building are considered: square or rectangular basis. For the building with square basis, the energy self-sufficiency is kept up to a higher number of the building levels (8 for Naples, 10 for Palermo) compared to the case of rectangular basis (7 levels for Naples, 9 for Palermo)