Photovoltaic Panels in a Single-Family House

In recent years the production of energy for own purposes from photovoltaic panels enjoys growing interest in Poland. In 2016 and 2017, more than a dozen thousand micro-installations (in the vast majority the photovoltaic) have been yearly connected to the network. However, the share of micro-installations in the total electricity production in Poland is still very small. Total power below 200 MW gives a share in the order of tenths of a percent. Comparing the installed capacity in photovoltaic sources in our country with the average of the European Union (over 3550 MW) we can expect it to grow in the coming years. Will this increase be generated by prosumers and their micro-installations? Yes, if they would find that it is just profitable.This paper discusses the key parameters—which are responsible for the profitability of investment in photovoltaics from the point of view of an individual customer—the owner of a detached house.