The increased use of renewable energy resources for rural electrification has encouraged research and experimental projects decreasing designs uncertainties. This paper presents a deep and critical review of the design of micro hydro-generation technologies for river applications. This article shows three principal aspects: design, analysis and computational tools to study vertical micro-turbines, including the ones that are not vertical but that are relevant for the actual research. An exhaustive review is presented and analyzed hereafter. An in-depth review analysis focused on design is carried out. As a result of this work, it is clear that despite the need for interest in using renewable resources technologies, there is still a lack of research about design focused on computational analysis, as evidenced by the limited number of publications so far.