Environmentalists are continuing to press the shipping industry to reduce carbon dioxide emissions, and Jose Maria Figueres, chairman of the group Carbon War Room, said “modern wind systems are demonstrating measurable and meaningful fuel savings for ships.”
Figueres predicts wind propulsion and technologies such as air bubble systems that lubricate ship hulls will be increasingly adopted and become mainstream.
American Shipper has written previously about the Flettner Rotor (“In the rotation,” July 2011), a technology first demonstrated in the 1920s that uses a phenomena known as the Magnus effect to create a force that drives ships forward.
Enercon, a German wind turbine company, has been using a ship equipped with Flettner rotors since 2010 to deliver its products, and now Finland’s Norsepower said the technology has been successfully tested by roll-on/roll-off carrier Bore on its ship Estraden.
Sea trials confirmed a fuel savings of 2.6 percent using a single small rotor sail on a route in the North Sea. With these fuel savings, the technology has a payback period of four years.
Based on the trials, Norsepower and Bore believe that an onboard system with two rotors has the potential to deliver a 5 percent efficiency savings on an ongoing basis to the Estraden.
Jörgen Mansnerus, vice president at Bore, said the rotors can be retrofitted without any off-hire costs, and are “extremely easy to use in practice. It’s our goal to find ways to establish sustainable shipping with minimal impact on our environment.” Bore has a fleet nine ro/ro vessels.
Tuomas Riski, chief executive officer of Norsepower, called the test “ground-breaking” for his company and “the wider development” of wind propulsion technology for shipping.
“The results suggest that when Norsepower’s technology is implemented at scale (with larger, multiple rotors), it can produce up to 20 percent net savings in fuel costs with a payback period of less than four years at current fuel prices, confirming that wind technologies are commercially-viable solutions that reduce fuel and carbon emissions in the industry,” he said.
Another Nordic company is promoting a hybrid vessel called the Vindskip, which is designed to use wind for propulsion in conjunction with a liquefied natural gas-fueled main engine.
Terje Lade, engineer and managing director of Lade AS, designed a hull that can serve as a wing sail.
“In appropriate wind conditions, the hull shape resembles a symmetrical airfoil as it generates an aerodynamic lift, pulling the ship forward. Estimated fuel savings will be up to 60 percent,” the company said, adding CO2 emissions could be cut by 80 percent.
On the high seas, Vindskip will benefit from free-blowing wind, making the vessel extremely energy efficient. For low-wind passages, in order to maneuver the ship on the open sea while also maintaining a constant speed, it’s equipped with environmentally friendly and cost-effective propulsion machinery running on LNG.
To calculate the optimal sailing route, researchers from the Fraunhofer Center for Maritime Logistics and Services (CML) in Germany developed a customized weather-routing software for Vindskip that considers meteorological data and then calculates a route with the optimum angle to the wind for maximum effect of the design.
“At angles close to headwind, the wind generates a force in the ship’s direction. The ship is pulled forward. Since the hull is shaped like a symmetrical air foil, the oblique wind on the opposite side—leeward—has to travel a longer distance. This causes a vacuum that pulls the ship forward,” explained Lade, who holds a patent for the design.
This makes the freighter move at speeds of up to 18 to 19 knots, just as fast as conventionally powered ships.
Lade forecasted that the freighter will set sail by 2019.
This column was published in the July 2015 issue of American Shipper.