Kites as main propulsion systems for ships

OCEANERGY has designed a kite propulsion system for ships – as the main propulsion system. Our kite propulsion systems allow to fully navigate ships on all wind courses, upwind and downwind, including changes of direction. With this, the ship can fully navigate. An auxiliary electric propulsion system is only used as an emergency back up and to navigate close to harbors.

We have built a prototype of the kite propulsion system. It is still in small scale, able to handle kites up to 80 m2. It has undergone an extensive test program at OCEANERGY’s Kite Test Centre, which we operate in windy Cape Town (South Africa).

The kite propulsion system consists of two main components,
– our unique kite control system, including a pilot cockpit and artificial intelligence (AI) electronic control
– the kite itself: our low-weight yet high-load RES Kites.

Kite Control System K1

The K1 is unique and designed for maximum power and minimum operation cost. The K1 achieves this objective for instance by handling the kite ropes in a most cautious manner to allow for thinnest ropes and hence maximum power. The K1 can operate highest traction loads by the kite. These will eventually transform into maximum green electricity on board and then maximum hydrogen output.

The K1 is protected by a portfolio of granted and pending patents.

Kite Control System K1 - OCEANERGY low-cost green hydrogen production

Our high-load RES Kites

Our high-load RES Kits are equally unique and world’s first. These kites can handle up to 10x more load than existing low-weight kites in the market. Again, this translates directly into power and hydrogen with maximum MW output and then lowest H2 LCOE (levelized cost of energy).

OCEANERGY's RES Kites fly in low winds and deliver highest load and power

K1 in operation

The K1 is designed for fail-safe operation, a prerequisite to serve as main propulsion system for ships. The K1 produces green electricity directly, and additional propulsion for the ship. The pilot can decide on the ratio. OCEANERGY operates a prototype of the system in an extensive test and AI developement programme on land, and we are busy building a scaled version for the first small-scale prototype version for a demonstrator ship.

High-load Kite flight on OCEANERGY K1 Kite Control System

Advantages of a kite over other means to harvest wind

Kites have several advantages over other technologies to harvest wind energy, such as for instance sails, Flettner rotors, or rotating wind turbines. All these “old technologies” have in common that they are attached to masts, which develop torque at their base, leading to scaling problems.

  • One advantage is that a kite can make use of higher wind speeds of higher altitudes. A kite can harvest wind at 100m – 800m altitudes and more. Wind turbines harvest averaging at 80m – 120m. Sails and Flettner rotors even less.
  • Kites develop no torque to the point to which they are attached. Therefore there is only little heeling to a ship’s hull. The torque, which sails exert on their base, such as a ship hull, often limits their size. Same with the masts of wind turbines. Kites do not have this problem, which means that the size of the kite is theoretically unlimited.
  • A kite can actively fly through the air. The surface on which a kite flies is also called the flight envelope or the wind window. An actively flying kite increases the true air speed at the kite. It leads to enormous power output. Please keep in mind the cubic relationship between power and wind velocity as described here: solution requires to go far offshore >>

In summary a kite is much more effective than alternative methods to harvest wind energy and therefore superior. This, in combination with harvesting in strong and permanent wind will lead to low-cost hydrogen in large quantities.