GE Prepares Electrical System for French Tidal Array

With EDF set to operate a tidal energy array near Paimpol-Bréhat in Brittany, France at the end of 2015, GE Power Conversion reported that it is on track for finalization of the electrical conversion system, due for summer 2015.

GE’s Belfort team is working diligently to perform relevant tests before installing the system both subsea and onshore, the company said.

Two OpenHydro 16-metre turbines will be connected to a common subsea converter that will transform the current to high voltage direct current (HVDC) to provide 1MW of electricity. The power will be transmitted to the onshore station and eventually feed into the electrical grid. GE Power Conversion is undertaking development of the subsea converter as well as the onshore station.

The enclosure for the subsea converter is 9 meters in length, 5 meters in width and 4 meters in height – although still tiny compared to the tidal turbine which measures 16 meters in diameter, provided by OpenHydro, part of the DCNS Group.

The converter will be delivered to Brest and be installed by DCNS on the specific foundation designed by OpenHydro, which supports both the convertor and the 16-meter turbine.

The turbine comprises four key components: a horizontal axis rotor, a direct-drive permanent magnet generator, a hydrodynamic duct and a subsea gravity base foundation. Simplicity is a key advantage of the device, with no lubricants, seals or gearbox, resulting in reduced maintenance requirements.

The turbines with the converter are placed directly onto the seabed, deep enough so as not to pose a hazard to shipping.

The MV7000, once installed in the onshore substation, converts HVDC back to HVAC which is compatible with the French grid.

Furthermore, GE’s subsea converter also has the potential for future upgrades, as its design leaves the possibility of connecting with two additional turbines.

Image: GE