Experimental measurement of the loads on tidal turbines using conditions derived from field measurements

Tidal turbines are typically conservatively designed leading to additional, associated, expense. Overdesign is commonly driven by a limited understanding of the conditions at the deployment site. The RealTide project aims to tackle this conservative design by producing an open-access database of field and experimental data, providing a fuller understanding of the spatial and temporal variation of these conditions and the interaction of real-world conditions with the turbine. Under this project, high resolution Acoustic Doppler Current Profilers (ADCPs) have been deployed in the Fromveur passage (France) alongside the Sabella D10 tidal device. When interpreted using a high resolution three-dimensional TELEMAC model of the tidal environment, a number of both typical operational and energetic conditions have been identified. These results show that the influence of waves subjects even bottom mounted turbines to large variation in velocity. Tests in FloWave have been conducted under representative conditions that combine multi-directional waves with noncolinear currents. A highly controllable, three-bladed, model turbine has been tested under these conditions, with device power and force measurements. The RealTide database has been populated with information about the real world and experimental conditions and the response of and loads experienced by the turbine. This data provides a set of information that may be applied to the design of real-world devices deployed in the ocean. The device data is complemented by a set of, spatially dense, acoustic Doppler velocimeter measurements characterising the model turbine’s inflow, near field, and wake. Particular attention is paid to ensuring the resulting open-access database is correctly quality assured and practical to access, providing maximum benefit for academic and industrial users alike.