Insight into the usage of turbine current converters on the Southern Brazilian Shelf

Abstract

The continuous growth of the world population increases the demand and competition for energy, requiring an immense effort for nonrenewable energy sources availability. Application of marine currents for electricity generation could offer a distinct advantage over other renewable energy sources due to 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, especially the turbine-based current energy converter, which demonstrated high energy generation capacity and that have already been in operation. The tridimensional model TELEMAC3D was used to investigate the hydrodynamic processes. This model was coupled with the energy conversion module in order to prospect the best energy spots for marine current energy in the Southern Brazilian Shelf. The study area has shown two viable regions with high potential for exploitation of energy from marine currents, however, the more viable region for the installation of current converters is the northern region, bounded between the Conceição Lighthouse and the Solidao Lighthouse, reaching an average power around 10 kW/Day and integrated values of 3.5 MW/Year. The highest levels of power generation were found at intervals of 16 days, showing high correlation with events associated with the passage of meteorological fronts along the study region. This paper details the design of a turbines farm containing ten helicoidal turbines. With three grids a study computing one year of simulation with the TELEMAC-3D model coupled with the energy conversion module was carried out. It was possible to indicate an interest area for trial tests of modelling a turbine farm. The northern region site, on the structural scenario, stands out keeping high conversion rates during events of great potential energy. This improvement happens due to the intensification effects of the current field associated with the presence of the physical structure which enhances the efficiency of the site. No significant differences on the temporal variability pattern between the simulations studied were estimated, showing that the presence of the structures does not impact on changes in the energy conversion temporal pattern on the temporal scales studies in this work. The configuration settled for this study predicted an annual power output of 144,54 GWh which is equivalent to 0,53% of the whole energetic consumption of the Rio Grande do Sul State in 2010.