Viability of the application of marine current power generators in the south Brazilian shelf

Abstract

Abstract The continuing growth in the world population has increased the demand and competition for energy, such that immense efforts are required to make non-renewable energy sources available. Using marine currents to generate electricity offers a distinct advantage over other renewable energy sources because of the regular and predictable nature of the resource. Therefore, in addition to promoting the development of new technologies, global policies for the generation of renewable and clean energy are being strengthened. Several methods of energy conversion have been developed over the years: the turbine-based current energy converter, in particular, has demonstrated high energy generation capacity and is already in operation. In this study, the three-dimensional model TELEMAC3D was used to investigate the hydrodynamic processes. This model was coupled with an energy conversion module to determine the best energy sites for marine current energy generation in the southern Brazilian shelf. Two viable regions were found in the region of study that exhibited high potential for energy generation from marine currents; however, the northern region has been found to be a more viable region for the installation of current converters and can reach an average power of approximately 10 kW per day and integrated values of 3.5 MW per year. The highest levels of power generation were found at 16-day intervals, showing a high correlation with events associated with the passage of meteorological fronts along the region of study. In this study, we design a turbine farm with ten helicoidal turbines. Three grids were used in a one-year simulation of the TELEMAC3D model that was coupled with an energy conversion module. The simulation results were used to identify a suitable region for trial tests on a model turbine farm. For a simulation with physical structures, the northern region site was notable because high conversion rates were maintained during events of high potential energy. This enhanced electricity generation occurred because of the intensification of the current field by a physical structure that enhanced the efficiency of the site. No significant differences in the temporal variability pattern were estimated between simulations with and without structures; thus, the presence of structures did not change the temporal energy conversion pattern on the time scales considered in this study. An annual power output of 59.39 GW h was predicted for the turbine configuration that was chosen for this study, which was equivalent to 0.22% of the entire energetic consumption of Rio Grande do Sul State in 2010.