Wrage added that the SkySails system – which operates at altitudes of between 300 and 400 meters – was able to save fuel by replacing the propulsion power that would normally be produced by, for instance, a diesel-burning engine.
"If you use a kite, then in ideal conditions you save 10 tons of oil per day," he said, adding that on average, three tons of oil could be saved per day.
Only two ships are currently using the system, which Wrage put down to the slowdown in the shipping industry in the years since the 2008 financial crisis.
"A lot of ship owners are on their knees and in that environment it's extremely difficult to sell such an innovation," he said.
With this in mind, the company has also launched what Wrage describes as "performance-optimising software for commercial vessels."
Developed by SkySails and LEMAG – a German company that specializes in making measuring instruments – the Vessel Performance Manager enables crews to optimize a boat's efficiency using real time data on everything from fuel consumption to engine performance.
Looking forward, Wrage was confident that the kite-propulsion system was a viable proposition for the shipping industry once the market recovered.
"We still deeply believe that ship owners cannot afford to waste wind in the long run," he said. "It's offshore; it's a tremendous source of energy; it's cheap."