Buying local is a great idea—when you’re talking about products that could be grown or made locally. But what about things you can’t get at home, like that hybrid manufactured in Japan? Or that energy-saving appliance from Denmark? Chances are it got here through marine shipping, a form of transportation that emits more sulfur dioxide that all the world’s cars, trucks, and buses combined, and is responsible for three percent of the world’s carbon dioxide emissions. 

But a less polluting, more efficient solution may be on the horizon, in the form of wind-propelled cargo vessels. This year, for the first time in decades, a sail-powered cargo ship will cross the ocean, using a combination of conventional engines and a gigantic kite.  This 160-square-meter kite will tow the MS Beluga SkySails, a 140-meter cargo freighter operated by Beluga Shipping. Raised and lowered by computer, the kite system can cost as much as a few million dollars to install, but could save shipping companies up to 50 percent in fuel costs (and thus pays for itself in just three years). That’s according to Stephan Wrage, CEO of the Hamburg-based SkySails, who says the idea actually came to him decades ago.

“At the age of 15, I was dragged by a kite along the beach at full speed” recalls Wrage. “I asked myself, how could we use this immense power in another way? From this, the idea was born to use the considerable potential for towing ships.”

By some estimates, shipping emits nearly twice as much CO2 as aviation—a fact that has largely escaped the public’s attention. Recently, though, the European Commission as well as the United Nations have begun to focus on the problem.  Feeling pressured, the International Maritime Organization agreed last October to set a timetable for CO2 reductions, a development which could help pave the way for emissions-cutting technologies like kite sails.

The shipping industry, though, has historically been slow to adopt new technology, says Dave Culp, CEO of California-based KiteShip, and designer of a competing system. Since Culp first began experimenting with kite-propelled vessels in the ’70s, he has seen interest in wind power wax and wane with the rise and fall of oil prices.  In the ’80s, the Japanese oil tanker Shin Aitoku Maru was equipped with computer-directed, self-raising sails that oriented themselves toward the wind.  Unfortunately, mast-based systems are considered too tall to navigate around most ports; it doesn’t help that they also cause their ships to list. What really doomed the Maru, though, was the drop in oil prices.  

With new technology and heightened awareness about global warming though, SkySails and KiteShip think it may finally be time for the sailing cargo ship to take off. Culp says his system, completed in 2002, is better designed and more cost-effective.

“I will challenge anyone to find another green technology that is immediately profitable without subsidy,” Culp says his system, completed in 2002, is better designed and more cost-effective than past endeavors, and will ride out the fluctuations in the energy market. The cost of making payments on his system is lower than the amount saved in fuel costs, he says, although shipping companies have so far shied away from being the first to put that claim to the test. SkySails, meanwhile, has overcome that hurdle, and will install two to four systems this year. Most shipping companies, however, simply intend to install older emissions reduction technology, such as exhaust scrubbing systems that run $4 million to $6 million per ship.  That’s twice the cost of KiteShip’s system.  So why the reluctance to switch to sails? 

Unlike sails, scrubbers increase costs (their operation adds as much as five percent to fuel costs)—but since they’re a familiar technology, people accept this as status quo.

Another problem is shipping schedules.  In fact, the shipping industry didn’t abandon wind power because it was too slow—engine-powered ships didn’t beat 19th-century sailing clippers for speed until the 1920s—but because wind is inconsistent. Of course, kite-equipped ships can always revert to engine power when the wind dies, but at this point, the industry prefers technology for which costs and benefits can be calculated precisely.

Ultimately, though, proponents of wind power predict that our reliance on engine propulsion will become too costly, forcing shipping schedules to become more variable.  Already, the high cost of oil-based shipping is creating a market niche for sailing cargo vessels, which were once considered too unreliable.  For the past year, the Hawaii-based S/V Kwai has been sailing a South Pacific route, reviving a lost art. Co-owner April Fountain says business has been thriving.  Most of her customers are on smaller islands that are not serviced by large cargo vessels and can no longer afford the costs of air shipping in an era of expensive fuel.  

“When we come into port and start pulling 300 tons of cargo from our hold using hooks and a wench, the stevedores just stare at us in amazement,” Fountain says. Her operation resembles a scene from ports a century ago. “They haven’t seen anything like it in their lifetime.”

They haven’t yet seen the MS Beluga SkySails, either.

Story by Justin Tyler Clark. This article originally appeared in Plenty in August 2007.

Copyright Environ Press 2007

Sail of the century
Shipping technology of the future borrows from the past.