Wind-powered freighter

The majority the world's trade is done through shipping. About 90 percent in all.

But the huge ocean freighters that carry the things we buy and sell are often charged with polluting the seas as they run on fossil fuels.

This has inspired a Norwegian naval engineer to look for an alternative, and he says he has found one: a freighter powered by wind.

Norway has always been a seafaring nation - so perhaps it is no a coincidence that a Norwegian naval engineer should want to revolutionize international shipping.

Terje Lade has little time for small, passenger ships, though - his dream liner is 46 meters high.

That's the proposed height of Lade's freighter.

And it would be the first transport ship to be powered by wind and gas.

"My ship needs 60 percent less fuel and produces 80 percent less emissions," says Lade.

It is a pledge that captures the contemporary zeitgeist almost perfectly.

The vision

Lade's is not the only project out there. The competition between scientists and engineers to find alternatives to traditional shipping is running full steam ahead.

The reason being that from 2020, shipping fuel will only be allowed to consist of 0.1 percent of sulfur. Sulfur is cited as a large burden on the world's oceans, affecting crab and shrimp populations.

But reducing the level of sulfur in fuel can make it more expensive.

It presents shipping companies with a challenge: how to reduce fuel costs while at the same time meeting emissions guidelines.

Lade hopes his project will be the breakthrough. His "Vindskip" (or "windship") does not rely on heavy fuels, but on wind.

The question is, is it fast enough for our modern times?

A 19th century ship?

Some critics have described the Vindskip as an anachronism - or worse - uncompetitive.

But Lade and a team of researchers at the Fraunhofer Center for Maritime Logistics and Service (CML) say they are confident.

One look at a "Vindskip" model and it is clear Lade's ship is not a thing of the past.

Instead of classical masts and sails, the model's hulk is designed to serve as the freighter's sail.

"The wind is converted into power," Lade explains. "Just as in any aircraft. The only difference is that the ship does not get pushed upward, but forward."

He says the Vindskip could reach between 18 and 19 knots, making it just as fast as a conventional freighter.

When the wind drops, the Vindskip will run on liquefied natural gas (LNG).

The sail and the wind

Designing a model is one thing. But without tests and scientific studies, Lade's dream will remain just that.

At the CML in Hamburg, researchers have been busy developing a "weather routing module" for his kind of ship.

The software will calculate routes for the ship to allow it to make the most of the wind and maximize its speed.

Using data on aerodynamics, hydrodynamics, wind speed and the height of waves, it will also help the ship avoid storms and other bad weather.

A ship for the future?

"We'll set sail in 2019," Lade says.

But others are less confident that his wind freighter will travel the big trade routes soon.

Some large shipping companies have expressed doubts about the freighter's cost efficiency and competitiveness.

As yet, there are no details about the ship's running costs. And the tests are far from complete.

But the thought of a future where large freighters plan their routes according to the winds again, sailing across the seas in an environmentally friendly fashion, is one to look forward to.