This thesis explores the influence of transmission network connection costs on the economic and financial parameters of power generating facilities. Elements of grid connection expenses have been analyzed together with the parameters they depend on. The thesis describes the most often used ways of determining connection fees. The basic parameters influencing the connection fees and the connected increase in investment cost. The influence of the increased investment cost due to connection fees on the levelized cost of electricity was analyzed. As the levelized cost of electricity is the minimum average electricity price that the power generating plant must achieve to be profitable, this comparison gives the scope of the difference in competitiveness of power generating facilities depending on the amount of the grid connection fee. The influence of the grid connection fees on economic and financial parameters of power generating facilities has been described in an example of one photovoltaic power plant investment project. The economic and financial parameters of the investment project have been compared for two reviewed scenarios. A sensitivity analysis has been performed for the optimal scenario taking into consideration various amounts of the grid reinforcement fee and different distances from the existing transmission network. In the sensitivity analysis financial and economic parameters have been determined for the assessed sub scenarios. This thesis confirms the hypothesis that location and connection power of a power generating facility together with the approach on determining connection fees can influence the levelized cost of electricity. The influence of increased investment cost caused by connection fees is significantly larger than the influence of increased operating cost caused by grid use fees. Following the analysis of the example of a photovoltaic plant investment project the conclusion is reached that the influence of grid connection cost on the economic and financial parameters of photovoltaic power generating facilities, although it can be significant, is lower than other parameters as the solar irradiance intensity.