Effects of Ice, Wind, Waves and Currents on Offshore Wind Turbines Destined for Atlantic Canada

Abstract The Canadian provinces of Newfoundland and Labrador (NL) and Nova Scotia (NS) are conducting assessment studies to investigate the use of offshore wind turbines to generate electricity. This paper deals with numerical simulations of two 15 MW offshore monopiles wind turbines: One is located off the western coast of Newfoundland Island (in water depth of 45 m) and the other is located off the northern coast of Nova Scotia (in water depth of 60 m). The two monopiles are similar, each has a diameter of 10 m, a tower of 150 m high, and blades rotor diameter of 240m. The environmental conditions (ice, wind, waves and currents) are also fairly similar; however, the water depth is different. The objective of this work is to conduct numerical parametric analyses to investigate the effects of environmental conditions (ice, wind, waves, and currents) on the behaviour of the monopiles when operating in “production mode”. All simulations were carried out using an open-source code, called OpenFAST. The environmental parameters were obtained from a metocean investigation of the region. In this paper, including ice loads on the monopiles in offshore Atlantic Canada is a significant contribution to the literature. For the simulations, the ice thickness was varied between 0.5 m and 1.6 m, the wind speeds were varied from 10 m/s to 20 m/s, the wave heights were varied between 1.7 m to 4.9 m, and current speeds were varied from 0.05 m/s to 0.25 m/s. The results of the simulations are presented and discussed, and conclusions and recommendations are provided.