In the last few years, interest has been increasingly focused on alternative and renewable sources of energy. Wind energy as an alternative to fossil fuels is receiving close attention while the number megawatts produced has been rapidly increasing. In many locations in the United States and internationally, construction of onshore wind farms has raised environmental and aesthetic concerns. In addition, the terrestrial wind cycle and the daily energy use cycle are not well matched, with peak winds occurring when the energy demand is at its lowest, requiring the development of energy storage strategies and devices. On the other hand, offshore wind farm development can avoid most of the aesthetic issues, with the added benefit of stronger and sustained winds at lower heights and more aligned wind and usage cycles.
The goal of this proposal is to evaluate the most effective foundation system for offshore wind towers by examining the performance of different systems when the structure is subjected to both wind and wave loading.
The project will carry out centrifuge testing in the NEES@Rensselaer facility. The testing program will focus on monopiles and suction caissons. Preliminary testing will be conducted using testbeds at Texas A&M University to evaluate the design of the tools and the models, as well as the sensors. The testing will be used to characterize the response of the foundations systems under a comprehensive range of loading conditions similar to those an offshore wind tower would be subjected to. Numerical analysis will be used to simulate the response of the tower-foundation-soil system with realistic soil models. The numerical and soil models will be validated against the testing.
The foundations currently used for offshore wind towers may not be the most effective solution for this application, especially in weaker soils. Foundation designs which evolved in the offshore oil and gas industry are not readily applicable to wind tower foundations offshore and design codes are not providing sufficient guidance for designers. Since foundations account for a significant part of the cost of offshore wind towers, choosing the most effective and most economical system will improve the viability of offshore wind energy generation.
