Passive Houses are buildings with low energy demand for heating (below 15 kW h/m(2) year), but provide comfortable indoor conditions. This paper presents the performance of an energy system designed for such a house located in Bucharest. Building system combines the earth-air heat exchange (EAHX) technology with photovoltaic panels. The photovoltaic panels were analyzed in terms of energy production and economic investment. The energy demand of the house was simulated using the EnergyPlus software in order to understand the house performance during cold and hot seasons using various occupancy scenarios. The results showed that the energy demand for a passive house is 14 kWh/m(2) year. Finally, the actual data measurement indicated that the passive house, has a good thermal comfort with a minimum energy consumption close to 13 kWh/m(2) year. The electricity generated from PV system during one year was 1556.5 kWh/year, the rest of necessary energy for consumption being supplied by the grid. (C) 2017 Elsevier B.V. All rights reserved.