The purpose of the proposed thesis is the systematic design and optimized configuration of a small hydropower plant (HPS) by using one or more hydro turbines. The first pillar of PhD is to find the optimal channel and the optimal drawing of the penstock (minimizing construction and operation costs) for each intake – tailrace pair. The differentiation lies in the fact that the channel is suitable for areas with a very small slope on stable ground, while the penstock is suitable for large slopes, practically in any type of terrain, but in general, quite more expensive than the open one.The purpose of the proposed thesis is the systematic design and optimized configuration of a small hydropower plant (HPS) by using one or more hydro turbines. The first pillar of PhD is to find the optimal channel and the optimal drawing of the penstock (minimizing construction and operation costs) for each intake – tailrace pair. The differentiation lies in the fact that the channel is suitable for areas with a very small slope on stable ground, while the penstock is suitable for large slopes, practically in any type of terrain, but in general, quite more expensive than the open one.In the second pillar of PhD, a study will be carried out through an exhaustive search or other optimization techniques for each pair of intake – tailrace pair, taking into account the topographic study that will have been completed, where all areas will have been characterized. The main objective is to find for each possible layout, penstock cross-section, the suitable hydro turbine, generator and transformer, under consideration of the nominal flow, taking into account the given gross head of intake – end, optimizing the design of the small hydro with one or more hydro turbines. Considering all the above results, an analytical techno-economic study will be applied, for each intake – tailrace pair.Last but not least, the first goal of every investment is the greatest possible profit with the minimum possible cost. Based on that, the third pillar will contain the optimal operation of a small hydropower plant with two or more hydro turbines, besides the “synergetic” and “hierarchical” methods by using, for example, the Lagrange method.