The article presents the results of a single-purpose optimization of the composition of the hybrid complex consist of the wind-solar and diesel power plants, according to the criterion of the minimum cost of electricity for a small settlement in given geographical conditions. An estimation of the impact of an additional criterion for the total investment cost limitation on a result of solving an optimization problem is given. It is shown that the ratio of the proportions of the solar and wind power plants is not constant when total investment cost changes and it changes to the exclusion of one of the renewable energy sources from the complex.