Abstract
Sustainable Marine Energy’s floating tidal platform PLAT-I 4.63 hosts four SCHOTTEL Hydro Instream Turbines with a 6.3m rotor diameter; the platform has a rated power of 280kW. PLAT-I underwent sea trials from 2017 to 2020, in Scotland and Nova Scotia. During the latest deployment in Grand Passage, Nova Scotia, the platform was operational on both flood and ebb tide, allowing comparison to be drawn between environmental conditions and the impact on power production and platform performance. The platform passively aligned to the flood and ebb tide and showed good stability to the dominant flow direction. The platform was free to rotate about the mooring turret and this feature was not affected by tide state, tide direction or strength. The power output for the platform met or exceeded numerical predictions. Individual turbine performance was slightly affected by tide direction, and thus velocity conditions, and turbine position relative to the hulls and mooring assembly; the power output and thrust for the turbines was very comparable to predictions from a blade element momentum model despite these marginal differences. The mooring performance could not be compared between flood and ebb due to differences in connection jewellery and load measurement device. This will be investigated in future deployments of PLAT-I systems. The platform performed well during the sea acceptance trials and was decommissioned in 2021. The second generation PLAT-I, PLAT-I 6.40, commenced sea acceptance trials in Grand Passage in 2021 prior to commercial deployment at FORCE for the Pempa’q project.