Airseas of Nantes, France, is developing 1000m2 kites for ships, which fly at 300m vertical height, with a 700m cable. Its models say the kites can save 20 per cent of fuel costs. They are suitable for use on tankers as well as most other vessels across the global fleet.
The company has a close relationship with aeroplane manufacturer Airbus. It was founded by former Airbus engineers, Airbus has an 11 per cent stake in the company, and is a launch customer.
Airbus has a plan to fit the kite on its vessel Ville de Bordeaux at the end of 2021. This is a ro-ro vessel used for transporting large components of its aircrafts from factories in Europe to the city of Mobile in the United States.
The technologies are developed by Airseas engineers and belong to Airseas, but the product development is based on the aeronautical expertise and experience of its engineers. Airseas remains independent from Airbus in terms of decision-making.
The kite actually works like an aeroplane wing. Instead of the wind blowing the kite and pulling the vessel, the wind blows across the kite. It is curved so that the wind has farther to go on one side than the other. This creates a suction force which moves the ship in the direction it is going.
Vincent Bernatets, CEO and Founder of Airseas, was an Airbus employee for 15 years, including as business development senior director and aircraft information systems operations director. He has a MSc in aeronautics from Stanford University.
Airseas is in discussion with a number of bulk, tanker and container shipping companies. Mr Bernatets is unable to reveal further details at this stage, except in the tanker sector it is “VLCCs and Suezmaxes in particular.” The company’s confirmed early customers include Airbus and Japanese shipping company “K” line.
Airseas modelling estimates that the kite can typically save 20 per cent of a vessel’s fuel, and the investment can make a return after 2.5 to 5 years. The 20 per cent figure “comes from both modelling and tests,” Mr Bernatets says. It has tested the wing and the typical wind power achievable on land, showing results consistent with the model.
Companies can improve the benefit they can get from wind power by taking it into account when making weather routing decisions, he says, if there is a choice of a route with a more favourable wind.
Airseas was founded in 2016. It has just moved into its new 6,000m2 headquarters, and plans to scale up production when it opens its 20,000m2 factory by 2024. The company anticipates producing about 75 sails over 2022-2024. It has 85 employees as of November 2021.
Installing and launching it
The kite and its apparatus is installed on the bow of the ship, bolted onto the deck. The apparatus includes a 35m mast from which to launch the kite, a winch, and fans to blow the kite out to its full size. Installation takes under 2 days. The bow of a tanker is a non Atex zone, Mr Bernatets says.
The kite is folded when not in use. To launch it, the kite is hoisted to the top of the mast with the winch, and then blown to its full shape using the fans.
There is a sophisticated system for releasing the wing while it is folded in half, ‘inflating’ it using fans, letting it take its shape with the extremities of the wing held together, and then releasing both ends of the wing at the final stage, so it takes its final flying shape. This whole process takes 20-30 minutes. The cable is 700m long.
The same process is followed backwards to store the kite.
Using wind power
The kite uses wind power to make a ‘suction’ force, the same as an aeroplane wing does.
An aeroplane wing is curved on the top and flat below, so the wind blowing over the wing has further to go, and the pressure above the wing is lower. This creates a suction force lifting the aeroplane. The suction force for the vessel kite uses the same method, but with the vessel being ‘sucked’ along the water, in the direction the vessel is travelling.
Airseas’ modelling estimates that wind can be useful 70 per cent of the time, so long as you have wind, and it has an angle of more than 40 degrees from the line of the ship.
Or to put in other words, if the vessel is going Northwards and you have a Northerly wind (blowing from North to South) then the wind power cannot be used. But if the wind direction is more than 40 degrees to East or West (or in 360 degrees terms, between 40 and 320 degrees), then it can be used.
The kite will typically fly at 300m vertical height. Winds at this height are typically double the strength of wind at ground level, Mr Bernatets says. But by doubling the wind strength, you get four times as much power from the wind. This is a similar rule of thumb to the one that says, to double a conventional vessel’s speed, you need four times more fuel.
The kite has a surface area of 1000m2.
There is an automation system which makes it possible to get the most propulsion power with the wing, without needing any manual piloting. It also makes operation of the wing completely “transparent or seamless” to the crew, Mr Bernatets says. “There is no need for human intervention, no workload for the crew or captain.”
Commercial trials
The first commercial trial will begin in December 2021, with the installation of a Seawing on Airbus’ vessel Ville de Bordeaux, operated by Louis Dreyfus Armateurs.
The second Seawing will be installed on a vessel from the Japanese shipping company “K” Line, which has dry cargo, container, LNG, ro-ro and tanker vessels.
K Line has been participating in the development and testing of the system. It announced in June 2019 that it would install the system on a cape size bulk carrier which normally operates between Japan and Australia, with installation now planned for summer 2022. In August 2021, “K” line confirmed it would like to fit a second kite on a new build cape size vessel.
Mr Bernatets hopes that shipping companies will be comfortable investing in these wind propulsion solutions before waiting for the outcome of the commercial trials, as wind propulsion will save time and costs towards the decarbonisation of the shipping sector.