Pyxis Ocean sets sail in August on its first voyage since being retrofitted with WindWings.
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Pyxis Ocean sets sail in August on its first voyage since being retrofitted with WindWings.
Cargill
More than a century after the age of sail made possible coal- and oil-burning ships, concerns about climate change are prompting a fresh look at ancient technology that can once again harness the wind to propel commercial cargo ships — this time with the goal of reducing emissions. Greenhouse gases.
Imagine what looks like the wings of a Boeing 747 with movable flaps, positioned vertically on the deck. The ship sails on minimal power from its giant engine as computerized sensors adjust the fiberglass wings to take advantage of wind speed and direction. This wind-assisted propulsion saves a significant amount of fuel and reduces carbon belching from the ship's stack. Many experts believe the idea has the potential to steer the dirty shipping industry toward a greener future.
“Shipping is unique,” says Gavin Allwright, secretary-general of the International Wind Association (IWSA), a non-profit trade organization that advocates for wind propulsion in commercial shipping. Since ancient times, ships have used clean, free wind energy, “then we carbonized and now we're back to zero carbon.”
At least that's the hope.
The shipping industry can save fuel and reduce emissions
About 90% of the world's goods — everything from soybeans to athletic shoes — are transported by sea. The tens of thousands of ships used to deliver these goods to global markets account for an estimated 3% of the world's carbon emissions each year, a figure that exceeds Japan's annual emissions. If left unchecked, greenhouse gas emissions from the shipping industry are expected to grow by 50% by 2050.
Although commercial shipping was not included in the 2015 Paris Agreement, there is a significant economic incentive for the industry to decarbonise. The EU's emissions trading system will cover the maritime industry from next year, meaning shipping companies will have to pay for their carbon emissions.
Also in 2024, the UN's International Maritime Organization (IMO) will classify each ship based on its cargo-carrying capacity and the number of grams of carbon dioxide it emits per nautical mile. Ships with lower ratings will be required to take corrective action or risk not being allowed to operate. It is part of the International Maritime Organization (IMO)'s ambitious goal to get the shipping industry to net-zero emissions by 2050.
Renewed interest in airships began gaining momentum in the early 2010s, and today there are about 30 large commercial vessels using one of a number of these technologies, Allwright says. Shipping giants Maersk and NYK are already trialling such systems. They are expected to reach 20 more in the coming months. So far, they are mostly “tests” to see if the concept is commercially viable.
In a recent trial, the 751-foot bulk carrier Pyxis Ocean operated by Cargill was retrofitted with two rigid sails, known as WindWings, inspired by those on contemporary America's Cup racers. The ship, carrying only water ballast, arrived in Paranagua, Brazil, last month after a voyage of about 10,000 nautical miles from Singapore.
The 123-foot-tall, hinged fiberglass and metal wings use the force of the wind to create lift and move the ship forward. The wings can be folded on deck in unfavorable winds or rough weather and while in port, where they may interfere with loading and unloading operations.
It took a significant amount of engineering and computer modeling to move the concept from high-tech racing boats to a commercial bulk carrier, says John Cooper, CEO of BAR Technologies, which developed the WindWings. In America's Cup boats, “hydrodynamic resistance is very low,” he says, compared to the “huge” dynamic drag of a commercial ship.
On its maiden voyage last month after being retrofitted and retrofitted, the 5-year-old Pyxis Ocean reached 16.2 knots (18.6 mph) with the WindWings working in tandem with the ship's engine running on minimal power, Cooper says.
Before departing for Brazil, the ship sailed briefly without the engine. “We raised the anchor, raised the wings, turned it into its flying shape, and then we set off on our way away from the anchorage,” he says. “The crew was amazed.”
Variations on the rigid wing concept are being tried elsewhere. One system, first developed in the 1920s, is a bigger departure. The “rotor sails,” or large cylinders made of carbon fiber, move the ship using a principle known as the Magnus effect, an aerodynamic force perpendicular to the direction of the air stream and the rotor axis.
“I would say there's competition now,” says Matthew Collett, a naval architect who teaches ship design at the University of Michigan. The wings on the Pyxis Ocean “are more complex, [but] Maybe more efficient. Rotor sails are very simple, and a little limited in what you can do with them.”
“But no one talks about the costs openly,” he adds.
In the case of WindWings, Cargill and BAR say the prototype of the system installed on a modified ship is not a good indicator of the final cost, either for initial installation or operation. Ships built from the keel up to improve wing technology will show a clearer picture.
The Windship Association's Allwright estimates that, on average, wing technology costs $3 million to $4 million for a $100 million ship. “It's not a big deal, but it's also not a huge expense,” he says.
With so many overlapping interests in the shipping industry, just getting approval to trial a system like WindWings is no small feat, according to Jean Deleman, president of Cargill Ocean Transportation.
“You have to work together and share the risks one way or another,” says Deleman. “The owner is not just going to put in all kinds of fixtures [a] ship if they don't know if someone will actually pay them for it.”
MC Shipping, a subsidiary of Mitsubishi Corp, owns the Pyxis Ocean, but Cargill, which operates it under a long-term charter, has agreed to provide the funds to install the WindWings, with the help of a small EU subsidy. “We get the fuel savings because that savings goes to the operator, and that's how we're going to make it work,” he says.
Newer, cleaner fuels are another idea for cutting emissions
On a retrofitted ship, like the Pyxis Ocean, it can take seven to ten years to recoup the initial investment in wing technology, “which is not very exciting for the average commercial operator in this industry,” admits Dieleman.
The shipping industry is also looking to new fuels, such as ammonia and methanol, that would be cleaner burning and produce less carbon – especially if used with new wind technologies. However, these clean fuels are likely to be much more expensive than today's relatively cheap, but more polluting, fuels.
WindWings are installed on the Pyxis Ocean at the COSCO shipyard in Shanghai, China, in August.
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WindWings are installed on the Pyxis Ocean at the COSCO shipyard in Shanghai, China, in August.
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Installing WindWings or similar technology on a cargo ship or on oil tankers is no easy task, Collett says, but it is simpler than retrofitting some other types of ships. “Deck space is a top priority for both vehicle carriers and container ships. So now you're giving up cargo as well as the ability to modify the ship's design,” he says. Despite these potential hurdles, French company Zéphyr & Borée, earlier this year, placed an order with South Korean shipbuilder Hyundai for five purpose-built wind vessels equipped with methanol-fueled engines.
Ships designed and built specifically to serve as wind ships that burn cleaner fuel are the future Diliman envisions. He says he could cut WindWings' 10-year return to just three to five years. In this case, it becomes “a very interesting thing on a ship that is usually, say, 20 to 25 years old.”
Fuel costs could be cut by about a third if the ship were built specifically with WindWings in mind, according to Dillman.
While Pyxis Ocean continues its trial, BergeBulk, which owns and operates a fleet of about 80 bulk carriers, plans to install WindWings on one of its ships. The rotor sails, made by Finland-based Norsepower, have been installed on commercial ships in China and Japan.
WindWings may be a completely modern version of ancient sailing ships, but the technology could revive some ancient ship ways that have long since fallen out of favor, says BAR's Cooper.
“You can see some of those old ways coming back,” Cooper says. “You know, there might be an argument to keep circling the world in one direction instead of moving back and forth. Just keep circling the world to take advantage of the trade winds.”
NPR international affairs correspondent Jackie Northam contributed to this report.
