Great application of a mix of old an new technologies in a way that makes sense. Kudos to the SkySails folks for bringing this to market. The Economist has more:

But the SkySails approach does away with masts and is much cheaper. The firm says it can outfit a ship with a kite system for between €400,000 and €2.5m, depending on the vessel’s size. Stephan Wrage, the boss of SkySails, says fuel savings will recoup these costs in just four or five years, assuming oil prices of $50 a barrel. Jesper Kanstrup, a senior naval architect at Knud E. Hansen, says the idea of pulling a ship with an inexpensive kite—attached to the structurally solid bow like a tugboat—had never occurred to him. “It’s a good idea,” he says.

Skysails reveals the essence of any successful (We’ll see) idea: economics, application, timing and luck!