Sailing into 2022 with wind-powered cargo ships

Use of wind-propulsion devices like towing kites and rotor sails set to double in 2022, experts say.
By Maria Gallucci

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An illustration of Airseas' kite towing the vessel Ville de Bordeaux (Airseas)

This year’s forecast for the global maritime industry looks particularly breezy. Sails, kites, wings and tubes are all set to appear on cargo vessels over the course of 2022, harnessing wind energy to reduce ships’ use of dirty diesel fuels. Experts count nearly two dozen new projects in the works as shipping companies look to limit emissions from carrying cargo by sea.

First on deck is a high-flying kite from Airseas, a French startup founded by former Airbus aeronautical engineers. Starting this month, Airseas will deploy its automated Seawing system on a cargo ship for the first time. The blue-and-white Ville de Bordeaux vessel will hoist the 5,400-square-foot parafoil during a six-month period of sea trials. Airbus ordered the kite for the vessel, which carries the company’s aircraft parts between France and the United States.

It’s a major milestone and the beginning of an adventure for us,” Stéphanie Lesage, general counsel for Airseas, told Canary Media.

Airseas installed the Seawing system in December on the front of the 500-foot-long vessel. With the flip of a switch, the kite automatically unfurls and positions itself in the wind, helping to tow the ship and lessen the workload of the main engines, which saves fuel. A pod attached to the kite’s tether gathers weather data to optimize the system’s performance. Once towing is no longer needed, the tether retracts and the kite folds back onto the bow of the ship.

The Seawing is meant to work without the crew’s intervention, though a 10-person team from Airseas will be onboard to test and fine-tune the system during trials, Lesage said. The startup already has another major customer lined up if all goes well. Japanese shipowner K Line has placed two orders for a 10,800-square-foot version of the parafoil, which will fly nearly 1,000 feet in the air.

Airseas estimates the larger kite will reduce ships’ fuel consumption and associated emissions by an average of 20 percent.

A fast fix for dirty ships

Shipping companies worldwide are facing rising pressure from regulators, retailers and consumers to address the industry’s massive footprint. International shipping contributes nearly 3 percent of total greenhouse gas emissions every year, making it more polluting than all of Germany.

The International Maritime Organization, the United Nations body that regulates the industry, has set goals of cutting shipping emissions in half from 2008 levels by 2050, and then of fully decarbonizing by the end of the century. The organization has also set energy-efficiency standards for new and existing ships. Environmental groups and researchers say much more stringent policies are needed to steer cargo ships away from fossil fuels and toward cleaner alternatives, potentially including green ammonia.

In the meantime, however, the measures are building support for wind-assisted propulsion” as an immediate, albeit partial, solution for addressing climate change.

The momentum in wind propulsion is continuing to grow, and there are early signs that investment, installations and production lines are starting to ramp up,” said Gavin Allwright, secretary of the International Windship Association. He described his outlook for the next two years as bright with a stiffening breeze.”

Twenty vessels will use some type of wind-blown device in the first quarter this year, he said. That number is expected to reach 40 vessels by the end of this year or into early 2023. Considering that nearly 100,000 merchant ships ply the world’s seas today, that hardly amounts to mainstream adoption. But a doubling of wind-assisted ships would still be a significant step for the emerging technology segment.

Spinning tubes to save fuel

Beyond high-flying kites, the shipping industry is set to gain more rotor sails this year as well. Each spinning cylinder drags air around itself to form areas of high and low pressures, which produces a forward thrust.

Finnish company Norsepower is installing a rotor sail on M/V Berlin, one of the largest battery-hybrid ferries in the world, which travels between Denmark and Germany. Ferry operator Scandlines first installed a 100-foot-tall tube on its other hybrid ferry, M/V Copenhagen, in May 2020 and found it reduced carbon emissions by 4 to 5 percent.

Hybrid ferry M/V Copenhagen with Norsepower's 100-foot-tall rotor sail (Scandlines)

Five other vessels use Norsepower’s tubes, including a massive new iron ore carrier chartered by Brazilian mining giant Vale. The bulky red ship has five 80-foot-high cylinders that together are expected to reduce fuel costs and emissions by about 8 percent, according to Norsepower.

Tuomas Riski, Norsepower CEO, said the company’s successful track record in recent years is drawing attention to wind propulsion from ship operators and cargo owners, who often foot the fuel bill. There is no doubt that competition in the market is rising,” he said. We welcome this.”

Wing sails take flight 

While rotor sails are the most common wind-assisted propulsion device on ships today, other technologies are steaming toward commercialization. Paris-based startup Ayro is building four of its rotating wing sails” this year, which will rise from the deck of the 400-foot-long cargo ship Canopée. Once completed, the vessel will carry parts of the Ariane 6 rocket launcher from Europe to French Guiana’s space center

An illustration shows the cargo ship Canopée with four Oceanwing 363 systems. (Ayro)

The company’s Oceanwing 363 system is composed of tall vertical sails, with each one split into two cloth panels. The panels can rotate 360 degrees, adjusting in response to wind conditions, or crumple toward the base when wind assistance is no longer needed. Sensors and motors automatically adjust the sails’ angles en route.

An illustration of Ayro's self-rotating Oceanwing (Ayro)

Ayro is a spinoff of the naval architecture firm VPLP, which designed and built the first Oceanwing prototype in 2016. Three years later, a pair of Oceanwings were installed on the Energy Observer, a sleek catamaran propelled entirely by renewable energy it captures on board. (Canary reporter Julian Spector boarded the vessel last year; watch or read about his adventures.)

Wing sails on the upcoming Canopée project will be more than 10 times bigger than the ones installed on Energy Observer, at roughly 3,900 square feet a piece. Ayro raised 10.5 million euros ($11.9 million) in funding last year to start constructing its Oceanwings in northern France.

Blowing air to harness wind

Another modern twist on the age-old sail is Michelins puffy, inflatable wing. The French tiremaker plans to fit its technology on a merchant ship for a trial run later this year.

A 3D rendering of Michelin's Wing Sail Mobility system on a cargo ship (Michelin)

Michelin unveiled its Wing Sail Mobility project in June 2021. (I covered the initial announcement for IEEE Spectrum.) Originally patented by two Swiss inventors, the wing is designed to slice through the air like an airplane wing, creating lift and propelling vessels across the water. With the push of a button, a telescopic mast rises to nearly 56 feet high. A small air compressor inflates the double-sided wing, which spans 1,000 square feet. The fabric and mast can both automatically retract when the vessel approaches a bridge or enters harbors.

Michelin estimates its system can improve a ship’s fuel efficiency by 20 percent, depending on the route and weather conditions. After the trial phase, the company said it expects to produce more of the marshmallowy sails.

Trimming bills for the cleaner fuels of the future

In addition to helping shipping companies curb their fossil-fuel appetites, wind propulsion devices could also aid in the transition to cleaner alternative fuels, said Lesage of Airseas. So-called green” ammonia and hydrogen — produced using renewables — are expected to cost significantly more than today’s sludgy bunker fuels. Reducing a ship’s overall fuel needs could help curb some of that sticker shock.

Wind is a free, abundant energy,” Lesage said. It will be a very important complementary solution to other disruptive technologies or alternative fuels when those are ready to get on board.”

Maria Gallucci is a senior reporter at Canary Media. She covers emerging clean energy technologies and efforts to electrify transportation and decarbonize heavy industry.