Modelling the impact of flow-driven turbine power plants on great wind-driven ocean currents and the assessment of their energy potential

The persistence in the strength and direction of western boundary great ocean currents suggests that flow-driven turbines implemented in these currents have great potential for energy exploitation. However, technological developments in the design and installation of power-generating plants in the ocean are tied to our capacity to accurately identify the most favourable sites and provide practical assessments of the potentially recoverable energy. Here we use a global eddy-resolving ocean model to demonstrate that large ocean power plants may exert feedback on oceanic circulation that results in highly unpredictable changes in ocean currents. Regionally, these changes can drastically modify the path of the current. In extreme cases this corresponds to a decrease in the available power by more than 80% from initial expectations. Ocean currents offer a potential source of power, but identification of the best sites requires a detailed understanding of their variability. Barnier et al. undertake global eddy-resolving ocean modelling to gain insight into the feedback from ocean power plants on currents and the changes they can induce.