Comparative analysis for distributed generation using ultra‐low head hydro, solar and wind energies

Summary Brazil has one of the richest river basins in the world and an energy matrix based mostly on hydroelectric power. Current national policy is increasingly promoting renewable sources like wind power and solar photovoltaic power. Technologies used in generation energy via hydro, wind, and solar sources can be employed in decentralized generation. This study describes a turbine for hydro energetic use in flow sites with heads up to 2.5 (m). A hydrodynamic study was performed using computational fluid dynamics (CFD) analysis to evaluate the performance of this turbine. For this, a three‐dimensional model of the turbine was considered, consisting of three computational domains, using periodicity to decrease the computational cost. The variation of the angular velocity and the volumetric flow were the boundary conditions. The turbulence model used was the shear stress transport. The draft tube geometry was modified according to the results of the CFD analysis. The efficiency and performance of the turbine improved from 79% to 80% as a result of this modification. A case study was conducted for a comparative financial analysis of the turbine proposed in this paper, with wind power and solar photovoltaic decentralized generation in Brazil. The difference between the present study and the previous studies is that there is an analysis of three renewable sources that are able to work in micro generation. In Brazil, the use of hydraulic energy to generate electricity is notorious, and the fact of being that it is one of the sources under analysis is due its high availability in the country; wind energy has presented attractive implementation costs when compared to other sources, and solar energy is, currently in Brazil, the source with the largest number of micro generation type plants, mainly after Brazilian electric energy agency normative resolutions. The paper introduces an economical analysis among an ultra‐low head turbine (with the description of the CFD analysis), wind and solar power under the same parameters.