If the world’s shipping fleet were a country, it would be the world’s sixth leading emitter of greenhouse gases. To reduce those emissions – and, not incidentally, to conserve expensive fossil fuels – cargo ship designers are now turning to the oldest source of power there is: the wind.
The new vessels, mainly still on drawing boards and in prototype, look nothing like the graceful schooners and galleons of centuries past. Last spring, for example, the University of Tokyo unveiled a model of its UT Wind Challenger at the Sea Japan trade show. It has nine masts, each 164-feet tall, with five rigid sails made of aluminum and fiber-reinforced plastic; the sails are hollow, designed to telescope into one another in rough weather or at anchor.
Then there is the 328-foot, 3,000-ton cargo carrier being designed by B9 Shipping (pronounced “benign”), part of the B9 Energy Group in Northern Ireland. Its three masts rise 180 feet, as tall as a 14-story building.
Powered by a combination of wind and a Rolls-Royce biogas engine, it is intended to operate with no fossil fuels.
A model of the B9 ship was tested in July at the University of Southampton in England.
“The tests were promising,” said Diane Gilpin, a founder-director of B9 Shipping. “They validated the economic case for deploying a B9 ship on certain trading routes.”
The next step, she said, is to seek financing for a full-size ship to demonstrate the technology. It would cost $45 million and take three years to build.
Several factors are driving efforts like these. Ships in North American waters are now required to burn low-sulfur oil, which costs 60 percent more than bunker fuel. The United Nations’ International Maritime Organization is also phasing in restrictions on greenhouse-gas emissions by commercial ships.
Meanwhile, the price of bunker fuel, which accounts for most of a vessel’s operating cost, has been rising steeply – 600 percent over the last 10 years.
Wind, of course, is cost- and emission-free. But none of the designs under consideration would replace a ship’s engine, only supplement it.
Nor is wind power practical for large vessels like container ships, which sail faster than 15 knots and need their deck space for cargo. But it is well suited for smaller, slower-moving ships, those in the 3,000- to 10,000-ton range. Such ships account for 10,000 vessels, one-fifth of the world’s total cargo ships, and are an essential link in the global supply chain.
Still, wind-powered technology faces a steep development curve before the industry will be ready to embrace it.
“There are a number of projects looking at the use of wind as a power source for shipping,” said Craig Eason, technology editor at the shipping newspaper Lloyd’s List. “Whether these projects will prove to be successful business ventures remains a question.”
Wind is one of a number of technological fixes under consideration to lower costs and emissions. They include replacing bunker fuel with liquid natural gas; streamlining hull designs; adding exhaust scrubbers; or just steaming more slowly.
All of these ideas face economic obstacles. Shipowners don’t necessarily pay for their ship’s fuel; the charterer does. So there is little incentive to make an energy-saving investment if the owner does not benefit financially.
Moreover, most sectors of the shipping industry are losing money, so it is not an ideal time to introduce new technologies.
“The industry is quite conservative,” said Roger Strevens, vice president for environment at the shipping company Wallenius Wilhelmsen Logistics. About wind power, he added, “There are a mix of significant technical, operational and economic hurdles to overcome.”
Or as Richard Pemberton, a marine technology expert at Southampton, put it, “The shipping industry will adopt whichever technology allows them to make a profit.”
One company that is well past the design stage is SkySails. Founded in 2001 in Hamburg, Germany, it has been selling automated towing kite systems for cargo ships for several years.
Resembling a giant paraglider, SkySails’ 3,500-square-foot kite is launched from a ship’s bow, pulling it forward when the wind is right. The company says that depending on wind conditions, fuel consumption can be reduced 10 to 35 percent. SkySails has installed its giant kites on six ships, and Cargill, the world’s largest charterer of dry bulk carriers, has announced plans to install the latest SkySails technology this year on its ship the Aghia Maina.
But wind technology for modern cargo ships goes back at least a quarter of a century. In 1986 Capt. D.C. Anderson of Earth Ship Limited fitted a 3,500-ton grain carrier, the Carib Alba, with an auxiliary wind-propulsion system called Comsail.
“On a perfect day,” he recalled, it “saved an astonishing 35 percent of fuel.”
But after oil prices collapsed that year, the Carib Alba’s owner took a blowtorch to Anderson’s sailing masts, leaving them on a pier in Houston and bringing a promising experiment to an abrupt conclusion after 363 days of testing.