In Slovakia, hydropower as a renewable energy source has a significant share. It is in the first place among renewable resources that are used in Slovakia. Due to the topicality of the issue, the thesis is focused on the investment project of a small hydroelectric power plant as a whole. The work evaluates and analyzes the economic efficiency of the use of hydropower on the example of a specific small hydropower plant. The economic analysis points to the adequacy of the investment itself, depending on the form of its financing. The work takes into account two basic methods of financing a small hydropower plant, namely equity and debt. Each variant of capital then offers three alternatives of view on a given issue at different discount values. The final summary of individual indicators offers an economic evaluation of the project. The secondary work discusses the legislative environment and possible obstacles, but also shortcomings in the further use of hydropower for energy purposes. The economic analysis shows that the investment in small hydropower projects is advantageous at the current guaranteed purchase prices using mostly own or provided the return on investment during the life of the project and foreign capital. In the next period, the further use of hydropower will be affected, in addition to legislation and overcoming other obstacles, especially by the economic efficiency of projects, which will depend on the approved purchase prices.