Concept
1. Under the action of the swell, a cylindrical floater moves horizontally, a back and forth movement called surge.
2. The innovative anchoring system converts this surge into pitch, i.e. a rotational movement of the cylinder around its axis.
3. Inside the floater there is a water pendulum at the bottom and two air-filled chambers at the top, separated by an axial vertical divider.
4. The rotation of the floater and the movement of the water pendulum will induce cycles of high and low pressure in these chambers and thus generate a flow of air through an orifice connecting them.
5. This air flow rotates a turbine directly coupled to a generator to produce electricity or to a pump to produce pressurised water.
Product
Seaturns develops an innovative wave energy converter:
- Unit power: 200 kW
- Function: electricity production
- Dimensions: Ø 6 m x L 12 m
- Net weight: 25-30 tons
The simple and robust system is designed to withstand hostile conditions and reduce maintenance costs.
The floater is composed of several elements made of welded sheets:
- two coaxial cylinders closed at their ends,
- stiffness partitions,
- an axial vertical divider.
Several floaters can be grouped together to form a wave farm by pooling the anchoring lines.
Robustness
A design focused on simplicity, robustness and compactness gives the floater a comparable durability to that of a buoy. The system does not use pistons, racks, belts, pulleys, end stops, etc. to limit the risk of failure and maintenance costs.
The power take-off (PTO), all electronic components and other sensitive elements are protected from the marine environment by being located inside a completely sealed volume.
Performance
The tank tests highlighted the good energy capture performance of the system.
The innovative patented anchoring system converts wave-induced surge into pitching motion, regardless of wave wavelength. This wide operating range means that it can be used in a large number of sites around the world.
Technical and economic optimisation
Study and simplification of the life cycle stages (manufacturing, transport, installation, maintenance) very early in the design phase. Installation costs are limited by using light and easily available means of intervention at sea. By taking advantage of the experience gained from existing systems, the design choices aim to limit maintenance costs (few mechanisms to be maintained, interchangeable modules).