SeaWing is a new hydrogenerator developed by the French company KiteWinder. It's a towed model, meaning it's attached to the stern of the sailboat and recharges once the boat is underway. Unlike the Aquagen model, which is towed 15 m behind the boat, the SeaWing has a link just 3 m long. The fish is very close to the transom.
Installation is simple, requiring only a fixed point on the transom. The cable doesn't rotate, so it doesn't transmit vibrations to the boat. The fish, which has 2 propellers, has its own alternators (motors embedded in the resin) which are connected by an electric cable to a charging unit in the boat. A software program optimizes the load by limiting the brake generated by managing the speed of rotation of the propellers. A system for braking the propellers completely is also provided when you want to bring the hydrogenerator back on board.
A phone application lets you control and monitor the operation of the hydrogenerator. It connects via Bluetooth pairing, displays charge curves and lets you manage the entire unit. Buttons on the casing eliminate the need to use a telephone.
The designer claims a load of 200 W from 5 knots and 300 W maximum at 12V, with a speed loss of between 0.1 and 0.3 knots.
This model has a float that pulls the fish towards the surface (the red ball), while a fin inclined at 12° ensures that the hydro-generator dives, balancing between these two opposing forces. Depending on the height at which the hydro is attached to the transom, it lies between 0.5 and 1 m below the surface, and sacrificial anodes are fitted to the propellers and fin to prevent corrosion. It weighs around 8 kg and its propellers have a diameter of 280 mm.
But why 2 propellers? The first prototype had only one propeller, and its rotation caused the rope to twist sharply. Now the 2 propellers rotate in counter-rotation, balancing the whole.
All that remains now is to check how this hydrogenerator behaves at sea, and especially when crossing fields of algae, as are common in the Atlantic.
This pretty toy is scheduled for 2025 (first delivery in January) and is offered at an introductory price of ?1,490. For the first 20 (then at ?1990 inc. VAT for the following).
