Optimization of photovoltaics panels area at Serbian zero-net energy building

In this study, the possibilities to decrease energy consumption of a residential building in Serbian conditions are analyzed. The building uses electricity for space heating system, heating of domestic hot water, lighting, and for other electric equipment. The electrical energy is generated by photovoltaics (PV) system and it may be consumed by the building or may be fed-in to the electricity grid. The major aim of the optimization of PV area is to determine the avoided electricity from the grid (avoided exergy), and to minimize the consumption of primary energy. The residential buildings with variable thermal insulation thickness, hot water consumption, life time, and PV's embodied energy are investigated, in order to achieve zero-net energy building or positive-net energy building. The buildings are presented by a mathematical model, in EnergyPlus environment. Open Studio plug-in in Google SketchUp was used for building virtual design, Hooke-Jeeves algorithm for optimization, and GENOPT software for software execution control. For the different areas of photovoltaics, the investigations gave the results for their optimal values. In that way, the fossil energy consumption and CO₂ emission are also minimized.