The renewable energy sources are day to day more important in our world. In my thesis, I am providing a design of the electrical system of a dwelling house with photovoltaic system. Firstly, I scrutinize the features of the building and I give an appraisement for the electrical energy consumption. Secondly, I review the opportunities of the photovoltaic power generation in Hungary. In the 3rd section I examine deep inside the low voltage electrical system designing, and this part will show the electrical track busway as well. Along this chapter, I expound, size and choose all the parts of the electrical system. At last but not least, in the 4th part of the dissertation, it shows all the steps which needed in a miniature pvotovoltaic power plant design. During the section I choose the solar panels, inverter and the elements of photovoltaic protection system.After that I analize the shadow effects on the roofs of the house. Furthermore I make calculation for the DC and AC cables. For the last step I simulate the working system and I rate results.