Sails and kites support cargo ships

Reducing fuel consumption in a breeze

Since mankind’s first endeavors on the high seas, we have taken advantage of the power of wind. In the past several years, cargo vessels have also made increasing use of wind power as a propulsion aid. Especially companies with fair trade and organic products often load their cargo on sailing ships. Beside the reduced speed, the largest stumbling block appears to be the limited space in the ships’ cargo holds. However, with the imminent tightening of emission regulations in the scope of IMO 2020, additional sails or kites are becoming more and more attractive as a support to conventional propulsion methods. The major benefits are cost savings and a reduction of the tremendous air pollution caused by sea transports.

Ships copy the principle of kiteboarding

The idea of using sails and kites is not totally new. Around the turn of the millennium, the Hamburg-based company SkySails was already experimenting with a fully automated towing kite propulsion system which should act as a support to the motors of cargo ships and large yachts. These systems also had the goal of making the ships more profitable and environment-friendly. During the maiden voyage in 2008, the kites were extensively tested on a route of almost twelve thousand nautical miles. Although the effects were not as far-reaching as expected, the company was satisfied with the trial runs. Unfortunately, the approaching global economic crisis and the consequent slump in fuel prices resulted in the promising project being put on ice.

Airbus revives the idea of stunt kites

Airbus has plans to power its large cargo ships on the high seas with the aid of giant stunt kites. AirSeas, a subsidiary of the European aircraft manufacturer, has developed a wind propulsion system for its own fleet – Airbus operates four freighters which, beside Europe, transport aircraft parts to plants in Mobile, USA as well as Tianjin, China. According to the manufacturer, the kites, which are up to 1,000 square meters large, will provide around 20 percent of the required propulsion energy and reduce fuel consumption by the same amount.

In fall 2018, the first kite was ordered and christened with the name “SeaWing”. Its use will be partially automated: When there is no wind, the sail remains folded up on the bow of the freighter. When the meteorological station reports a sufficiently strong supply of wind, the captain simply activates the sail with the push of a button. The kite flies at an altitude between 200 and 300 meters, where the currents of the wind are considered to be the most favorable. Connected to the ship by a light, yet extremely tearproof rope, the kite puts the force of the wind to maximum use.  As soon as the wind subsides, the kite sail is automatically lowered.

Saving millions and reducing emissions?

Naturally, AirSeas also wants to offer the stunt kite to other ocean carriers. These are facing mounting pressure due to the air pollution caused by their ships, since maritime transport is among the world’s largest polluters. For every ship equipped with a SeaWing, carriers can save one to two million dollars in fuel, AirSeas assures. Thanks to these cost savings, the costs for the system should pay themselves off within a short time. Airbus expects a reduction of carbon dioxide emissions by a lofty 8,000 t per year. In addition, the system leads to a reduction of pollutants such as sulfur dioxide, nitrous gases and carbon black. We wish this ambitious project the best of success as an – in the truest sense of the word – compelling transport aid.

Renault is interested in sails, too

Automotive manufacturer Renault is also betting on clean sail power as part of its goal of lowering its CO₂ emissions by a quarter between 2010 and 2022. The French automotive giant is the first customer of the Nantes-based company “Neoline”. The company has developed a (car) transport vessel with four sails and has recently begun the construction of the first of two ordered ships. The vessels are to be handed over to Renault in 2021 and will be used for shipping new cars into the French overseas territory of Saint Pierre and Miquelon off the coast of Canada.

The ship, which is 136 meters long and equipped with two twin masts, will be loaded by means of a ramp on the stern. Equipped with three loading spaces, it will be suited for the transport of all manner of goods, including heavy cargo, containers and oversize loads.

CO₂ savings of up to 90 percent?

According to the manufacturer “Neoline”, the technology allows for a CO₂ reduction of up to 90 percent compared to a conventional ship with the same capacity – while offering an absolutely acceptable cruising speed. The ships will be able to cross the Atlantic at 11 knots, so that they could reach their destination in 13 days. Conventional ships powered by heavy fuel oil take about eight days for the same route.

Fifteen crew members are required to operate the sail area of over 4,000 m². In the rear part of the hold, the “Neoliner” can even provide a height of 9.8 meters to accommodate special transports. Whether it’s out-of-gauge industrial machines, large trucks or the like – the company hopes that the enhanced loading flexibility will translate to greater profitability. After all, the competition does not sleep. With a pure ro-ro car transporter, Becker Marine Systems and Wallenius Marine are already planning the next promising cargo ship project with sail support.

Wherever these endeavors may lead, we’ll keep our fingers crossed for this propulsion idea and hope for a “stiff breeze”. The world's oceans would certainly be in for a change of scenery.