Nowadays, the Ukrainian electricity industry is experiencing difficult conditions, as it is operating in a mode of depletion of its production potential. At the same time, the transition to sustainable and renewable energy is the necessary basis for the country’s welfare and for ensuring its energy security. Therefore, today we cannot do without the additional attraction of sources of funding from investors. The purpose of the survey is to study the pattern and effectiveness of investments and identify links and dependencies between key technical and economic parameters and investments in renewable energy sources. To achieve this goal, the authors divided the study into four successive stages, which made it possible to study the subject of the study comprehensively. As a result of the study, results have been obtained that complement the existing theoretical, methodological, and practical developments. Mathematical calculations (using the example of the largest wind power plants in the south-eastern region) revealed transparent relationships and dependencies between the critical technical and economic parameters of the WPP of South-Eastern Ukraine and investments in the wind energy sector. Among them: the installation of 1 MW of additional WPP generating capacity requires an average of EUR 1.51 million of investment resources, and the production of one additional kWh of electricity requires an investment EUR 0.42 euros; therefore, providing an additional thousand households with WPP electricity is possible with an investment of EUR 1.345 million.