Oceanflow has successfully completed six months of continuous deployment of its Evopod™ low visual profile / low motion turbine support platform off the west coast of Scotland. The mono-turbine variant of Oceanflow’s semi-submerged tethered pod which the company calls E35-01 supports a 35kW rated output tidal stream turbine and has been continuously tested in the fast flowing currents and harsh wave environment of Sanda Sound since early August 2014. The trials have demonstrated Evopod’s low motions and survivability characteristics in the moderately fast flowing (4 to 5 knots) tidal site, which in the winter months is also exposed to a harsh wave environment from the Atlantic and Irish Sea. The floating platform’s streamlined surface piercing struts and turret mooring system ensure that the device always faces into the flow whatever the wave direction while the small waterplane area of the struts and the device’s deeply submerged tubular hull ensure that the buoy has very low motions compared to more conventional surface floating platforms or buoys. The unit rode out a particularly severe “weather bomb” storm in December which combined spring tides with record breaking wind speeds and wave heights which led to shipping being constrained to port and the downing of power lines.
The E35 unit has a very compact above waterline profile that supports mast mounted and hull mounted instrumentation for above and below waterline environmental and platform performance monitoring. While the device is primarily developed for tidal stream and ocean current power generation Oceanflow’s CEO Graeme Mackie says that a variant of the E35 platform could also supporting a more extensive electronic monitoring suite for environmental, maritime or defence applications with autonomous power supplied by batteries charged up by its underwater turbine generator.
The E35-01 unit in Sanda Sound is fitted with a 35kW rated generator driven by a 4.5m diameter turbine. The E35 unit in Sanda Sound will be exporting electricity into the grid later in 2015 via an umbilical and subsea cable connection. The umbilical and seabed power cable also transmit data to the company’s onshore control and monitoring container which is sited 0.75 nautical miles from the device’s moored location. The trials of the 12 ton Evopod floating platform off Scotland’s west coast follows on from extensive testing of a smaller 0.35 ton unit in the more sheltered waters of Strangford Narrows, Northern Ireland.
For more information, visit www.oceanflowenergy.com.