A COMPARATIVE STUDY OF JACKET FOUNDATIONS FOR OFFSHORE WIND TURBINES

Resumo

The increasing use of wind energy comes from the need to ensure diversity and energy supply,
as well as the search for renewable energy sources, reducing the environmental impacts accentuated by
the use of fossil fuels. In this context, the worldwide trend in the development of technologies associated
with the production of wind energy has become more present in several countries. In Brazil, the first
wind turbines were installed in the northeast region, that suffers most from the critical levels of water
reservoirs and is well known for its great wind potential, which contributes to the success obtained in
the production of onshore wind farms. Aiming at the constant increase of the production of this type of
energy, the studies for offshore turbine installations have started. This work aims to study the installation
of wind turbines in a water depth of 40m using jackets as foundations. The natural frequencies and
stresses in a jacket structure used to support 5MW and 10MW wind turbines are evaluated. The analyses
were performed considering static and environmental loads of wind, wave and current. It was possible
to verify that the structural set related to the 10MW turbine has greater periods of vibration, besides
greater efforts, becoming necessary to adapt the jacket, as base enlargement. In addition, an adjustment
of structures geometries was also necessary in order to obtain greater cost-benefit.