Estudio del potencial eólico en mar abierto y optimización de la producción energética en la implantación de grandes parques eólicos marinos

Abstract

Depletion of primary fossil energy sources, greenhouse gas emissions and the need for sustainable energy consumption make it necessary to change the energy model, with the preferential use of renewable energies, major due to they are essentially clean, indigenous and inexhaustible on a human scale, in addition to allowing a sustainable development of all the countries of our planet. Currently, wind energy, produced in wind farms connected to the electricity grid, is the second largest source of renewable energy worldwide, with an installed power of 591.5 GW at the end of 2018, with a large projection of the future in the energy context. In particular, the offshore wind industry, with an installed capacity of 23.1 GW, divided into more than 100 wind farms in operation, it is based on the experience of the land wind industry, as well as on the codes and standards of gas installations and oil companies in the sea. However, there are still barriers to overcome, such as estimating the energy produced by wind turbines in the open sea considering the boundary conditions, which would allow a more complete study of the viability of offshore wind farms. The identification of wind potential in a marine site is essential for a largescale project to be carried out. The uncertainty in the determination of energy production can be minimized by using expressions that identify the marine atmospheric boundary layer, such as the equation of the profile of the wind speed with the height of the similarity theory, applicable to the atmospheric surface layer. In this line, a study method is developed to determine the annual energy production of a wind turbine in the open sea, which takes into account the continuous variations of the atmospheric stability and the roughness of the sea surface. The input data of the method proposed and for the validation of the results are extracted from the German research platform FINO 3. The objective is to extend this method to the usual form of measurements for an energy feasibility study, that is, when they are carried out with measurement masts, where the meteorological data are obtained at levels much lower than those of a wind turbine hub. On the other hand, the campaign of measurements can be reduced in the research phase of a wind farm, when a statistical distribution adequately describes the variation of the wind speed of the study area, and it is usual that, in locations with moderate to strong winds, can be represented by the probability distribution of Weibull, although it is not described as a general function. For this reason, a statistical study of the wind applied to offshore sites is carried out, with data from the FINO 3 research platform and with two buoys from the National Data Bouy Center. The results obtained show that, in certain latitudes, this statistical distribution is not representative of the wind speed. Also, a study of wind turbulence in the open sea at different heights of the surface layer has been made, considering atmospheric stratification. Confirming, in all years, that the curves of the turbulence intensity, as a function of the wind speed, are kept below the curve of the class C, of low turbulence, of the normal turbulence model of the IEC 61400-3 standard. Finally, another line of research developed is the optimization of the implementation of offshore wind farms for geometric configurations with alignments of equidistant wind turbines, based on the greater extraction of wind energy due to the lower interaction of its wake. The case study presented is obtained with data from the Gran Canaria buoy, belonging to the network of deepwater buoys (REDEX) of Puertos del Estado, of the Ministerio de Fomento of the Government of Spain.