It’s the ultimate example of blue-sky thinking: attach a giant kite to the mast of a cargo ship to try to save fuel costs. But unlikely as it seems, this technology actually exists. Moreover it appears to work. Earlier this year, a 133m vessel belonging to the Bremen-based Beluga Group containing cargo transported by DHL completed a voyage from Germany to Venezuela flying a 160m2 kite from its deck. 


The idea works like so: a kite is automatically unfolded and winched out to heights of between 100m and 300m, taking advantage of the more consistent winds at such altitudes, which can generate the equivalent of about 6,800 horsepower, enough to help pull a boat through the water. If the wind drops or is too fierce, the kite can be winched back down and folded back into its case at the touch of a button. 


It seems so basic, yet it could save the shipping industry millions in fuel costs while giving it a much-needed sheen of green. The recent increase in global demand for goods has driven huge expansion in the shipping industry, so much so that maritime CO2 emissions are predicted to rise by 30% by 2020. Regulation is inevitable and this, combined with volatile fuel costs, means the industry needs to become much more efficient. Could giant kites be part of the answer? 


“These are best seen as an additional rather than alternative power source,” says Robert Ashdown, head of technical division at The Chamber of Shipping, “but if it can be proven they work, they will have a valuable part to play.” SkySails, the German-based company that developed the kite for the DHL voyage, claims the technology could reduce fuel costs and emissions by 10%–35% annually. Further trials are under way, and if it turns out the claims can be substantiated, you can bet there’ll be many more giant kites filling the skies.