In the presented article is analyzed aging of the photovoltaic power plant panels located in Dukovany. Photovoltaic power plant in Dukovany (identified also as PV power plant) is the oldest PV power plants built in the Czech Republic. PV power plant was put into service in 1998. After 17 years of working is slowly ending its life. This work compared an electricity production in individual years, decreasing of produce energy from the values given by the manufacturer and also describing visible defects on selected modules.