Wind + LNG a New Tack for Ship Design

| Norway and Germany
Vindskip 2015 CML Wind-powered freighter

The Vindskip hull acts as a large wing sail.

Researchers at Fraunhofer, a Munich-based application-oriented research organization, are assisting Norwegian engineer Terje Lade, managing director of the company Lade AS, to design an eco-efficient cargo ship. The outcome is Vindskip™ – a vessel powered by wind and liquefied natural gas (LNG) that uses Fraunhofer-developed software to ensure an optimum use of available wind energy.

International shipping fueled by heavy fuel oil is transporting 90 percent of all goods on earth, significantly contributing to pollution. The International Maritime Organization (IMO) wants to reduce the environmental impact of ocean liners. Starting from 2020, ships will only be allowed to use fuel containing maximum 0.1 percent sulfur in their fuel in certain areas, increasing operational expense. Shipping companies are thus facing a major challenge in reducing their fuel costs while complying with the emission guidelines.

With Vindskip, patent-holder Terje Lade has designed a type of vessel that utilizes wind for propulsion in place of heavy fuel oil. The hull of the freighter serves as a wing sail: on the high seas, Vindskip will benefit from free-blowing wind making it very energy efficient. For low-wind passages, in order to maneuver the ship on the open sea while also maintaining a constant speed, it is equipped with an environmentally friendly and cost-effective propulsion machinery running on liquefied natural gas (LNG).

The combination of wind and LNG as an alternative to heavy fuel oil reduces fuel consumption to an estimated 60 percent of a reference ship on average. Carbon dioxide emissions are reduced by 80 percent, according to calculations by the Norwegian company.

Researchers from Fraunhofer Center for Maritime Logistics and Services CML, a division of Fraunhofer Institute for Material Flow and Logistics IML, have developed a customized weather routing module for Vindskip that calculates the optimal sailing route based on prevailing meteorological conditions. “With our weather routing module the best route can be calculated in order to consume as little fuel as possible. As a result costs are reduced. After all, bunker expenses account for the largest part of the total costs in the shipping industry,” says Laura Walther, researcher at CML in Hamburg. For the complex calculations, the researcher and her team apply numerous parameters, such as aero- and hydrodynamic data as well as weather forecasts from the meteorological services, such as wind speed and wave height.

Lade explains the physics of wind power: “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. This makes the freighter move at speeds of up to 18 to 19 knots, hence just as fast as conventionally powered ships. Due to its very low fuel consumption, Vindskip™ can utilize liquefied natural gas (LNG) as fuel and still be capable – in the worst case – of 70 days of steaming between bunkering. Thus, it can meet all of today’s and tomorrow’s challenges with regards to fuel economy and emission control.”

By the end of January 2015, the software will be handed over to the company Lade AS. Vessel types that are particularly relevant to the Vindskip™-design, for which the weather routing module is developed, are ships like car and truck carriers, big ferries, container ships and LNG carriers. Terje Lade forecasts that the freighter will set sail as soon as 2019. First, the ship model has to pass numerous tests in a marine research model tank. Tests in wind tunnels have already been completed successfully.

(Source: Fraunhofer)

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