This bachelor thesis aims to analyse the physical theory behind the photovoltaic cells and propose extension measurements for a modernised on-line laboratory. The first part of this thesis describes the theory of the photovoltaic conversion of solar energy into electricity. The p-n junction is described in detail because of its importance for a thorough understanding of the subject. The temperature dependence of a photovoltaic panel, i.e. the negative impact of rising temperature on the output power, is also described here. The contributions of this thesis include a summary of the current situation and the system of state subsidies for the current year as well as a proposal for an extension of measurements in an on-line laboratory, which is...