The creators of the company Sereo (Structure of Study and Research on the Offshore Wind turbines), applied for a patent concerning an innovative concept of floating wind turbine
- Plan d’exécutionFR N° 09 04784 deposited on October 05th, 2009
- Improved patent deposited on October 2012 (FR N° 12 02855)
The innovation bears on a particular architecture of floating wind turbine « V » shape twin-rotor, allowing to improve the technologies of floating wind turbines actually known, for operations in coastal areas where founded wind turbines are not suitable, including important depth on any sea bed type, where the constraints of acceptability are the least penalizing, with regard to the conflicts of use of the concerned zones.
After a first little scale model, Sereo’s objective is to study the performance and the operability of a demonstrator with less reduced scale.
The V-shape twin-rotor structure pivots on itself around a rotating coupling system, situated above the surface of the water :
- Piloting the thrust asymmetry in the two rotors ensures natural orientation, including with presence of waves and swell
- Natural yaw control with differential pitch variation of the blades
- No reaction on the floating structure, the anchor lines are not solicited vs rotating reaction
- Reduction of the weight and of the cost price of structures
- Reduced aerodynamic/hydrodynamic interaction
- Better response to stresses simultaneously imposed by variations of wind direction and by movements caused by waves and swell
- It is therefore possible to produce on average more electric power (maximum possible wind captured) for a given area of exploitation and at a lower cost
Two or three blades wind turbines :
- Better response to inherent dynamic stresses
- Integrated structure easy to transport
Spar Platform :
- Most of the structure is under the sea surface
- Good stability in waves and swell with the softest possible motions allowed by the SPAR geometry
Mutualization of the components of structure and anchorage, particularly expensive.
More advantageous production cost with regard to a mono rotor solution.
Densification of the power production : Wind turbines monorotor must be normally taken away from 3 to 5 times their diameter, to avoid the aerodynamic disturbances emitted downstream to a rotor.
Transport ,erection and operation simplified
- Dry assembly on the ground and horizontal launching
- Horizontal towing supported by simple floats with low draught or horizontal carriage of several wind turbines on supply vessels
- Anchoring by classical and economical anchor lines tightened from surface
- No heavy offshore crane for handling permits low erection cost
Completely competitive power cost, at both levels, manufacturing the wind turbine and installing it.
Objective < 3.5 M€ the installed MW (equivalent to the « founded » offshore wind turbine in little deep waters < 40m)
The Sereo Project was certified by the « Pôle de compétitivité EMC2 » in november 2013