The paper describes the basic parts, characteristics of operation and production of solar power plants and the method of connecting them to the power grid. The basic structure of the costs of building a solar power plant is stated, and a model for analyzing the economic profitability of the construction is created. The basic economic parameters used in the analysis of the profitability of the project are defined. On the selected test example (location Split and Zagreb), based on the created model, an analysis of the economic profitability of the construction was carried out with regard to the currently valid purchase prices of electricity and currently valid equipment costs.