Hybrid wind-powered ship designs set decarbonisation pace

An artist’s impression of Windship’s triple-wing mast design. Credit: Windship
An artist’s impression of Windship’s triple-wing mast design. Credit: Windship

The gathering environmental storm is driving shipping back to the future with the development of highly efficient wind systems. Coupled with a carbon-neutral biofuels breakthrough, the systems will deliver more than the 50% carbon reductions demanded by the International Maritime Organization (IMO) well in advance of its 2050 deadline.

Windship has announced its triple-wing mast that will increase a vessel’s power substantially.

“Three 35 m rig sets on a ship would produce on average 200 kt of thrust on an annual basis, including sailing ballast and sailing at times when the engines are needed using the diesel electric power. This number is a result of 10 years’ weather routing between Brazil and Dalian in China and allows for full load and ballast and all wind strengths and directions over this period. It is a good average, and on our 59,000 dwt test vessel, it produced on average a 33% fuel saving,” Windship designer and director Simon Rogers explained.

However, Windship is designed with a diesel-electric propulsion system with four auxiliary engines installed driving twin variable-pitch propellers that will operate on biofuel and maintain the ship’s performance in adverse wind conditions while keeping the emissions totally carbon-neutral, according to the designers.

Rogers used his experience in America’s Cup yacht design to develop an optimised 60,000 dwt bulk carrier using lightweight carbon composites to manufacture the ‘wings’ and what he described as “essentially the base of a crane” to anchor the 125-tonne foils to the vessel structure. The patented triple-foil concept was developed from the single-foil concept, Rogers said.

Windship Trifoil. Credit: Windship

Former Stena executive and Windship director Lars Carlsson told an audience in London that Windship’s conservative projections show that the triple-foil wings, also known as the Windship Auxiliary Sail Propulsion (WASP) system, would generate sufficient power on a Panamax vessel to cut emissions by 30%.

However, the company believes that “optimisation of the ship and the ship operation for the IMO comparison vessel type, built in 2008, is projected to save a further 20% in fuel consumption. This is existing technology among more advanced shipping companies,” a Windship statement said.

Retrofitting foils can take up to two weeks but no drydocking is necessary and the training of a single crew member to operate the wings is comparatively straightforward as the wings, which like an aeroplane’s wings have flaps at the trailing edge, are fully automated and essentially operate at a flick of a switch.

Should the sails need to be in a neutral position due to high winds, the sails can be feathered or will feather automatically, releasing the positioning mechanism and allowing the sails to freely move to the neutral position like a weather vane.

“Carbon-neutral vessels are to come, but these vessels could save up to 80% in fuel. It is the silver bullet that the industry has been looking for, according to Lloyd’s Register,” Carlsson said.

A breakthrough in the production of bioethanol, a carbon-neutral fuel, in the coming years will add fuel to the green storm. Abdelrahman Zaky, a researcher at Nottingham University in the United Kingdom, has developed a set of marine yeasts that will enable the fermentation process used to create bioethanol to be carried out in seawater.

Abdelrahman Zaky. Credit: Abdelrahman Zaky

“The production of bioethanol has been going on for a long time,” explained Zaky, “but it needs three elements – the substrate, yeast, and fresh water. Molasses is often used as the substrate and that takes up a lot of arable land that could be used to grow food, while freshwater was necessary to complete the process.”

According to Zaky, some 72% of the earth’s surface is covered with seawater so it is in plentiful supply. However, in the past, yeasts used in the fermentation process were usable only in fresh water, which is itself a precious commodity. Zaky’s breakthrough was to develop yeasts that have adapted to the ocean environment and can ferment molasses to deliver the fuel.

“I’m now looking to find a way to ferment seaweed that can be farmed at sea and, in the long run, can produce as much energy as the planet needs,” said Zaky, who estimated that funding of about GBP500,000 (USD656,000) would be enough to make the final breakthrough in the development of this biofuel.