Bridge Support Structure for Horizontal Axis Tidal Turbines Parametric Study

Many island countries are heavily dependent on diesel fuel for electricity, which contributes to harmful emissions and high electricity costs in these locations. Archipelagos create channel opportunities that produce higher current velocity potential that can be utilized. In the Caribbean archipelago, we focused on a site in the US Virgin Islands which was selected through satellite images and confirmed using USCROMS current mapping. In this paper, a novel bridge-like support structure for horizontal axis tidal turbines (HATTs) is being proposed that can better utilize surface current velocities within a channel and create a more efficient operation and maintenance (OPEX) process. This design is based on NREL's RM 4 current energy converter and optimized to better suit known issues that lead to the failure of tidal energy in these locations. In isolated locations like archipelagoes, the extraction and maintenance of these devices will be extremely costly and inefficient leading to these devices not being economically viable. With a bridge-like structure that has HATTs attached, allows for easier access for OPEX and opportunity for local labor without the need for special large-scale devices. With current speeds being depth dependent, these HATTs can be launched at varying depths that would be most effective for each location. We use Solidworks to develop the model of the structural design. An actuator disk model will be utilized in determining the loads on the structure as a function of number of turbines, depth, and current speeds. This study confirms that this structural design can support several tidal turbine devices under varying conditions. This design is shown to be more efficient for archipelagos in utilizing higher current potential and allowing easier access for operation and maintenance of the HATT devices.