Its owners, Enercon, a major wind turbine manufacturer, developed the design for E-Ship 1 as a means of company promotion, but also as a real way to reduce fuel costs, and the environmental impact of the ship. No one is saying how much the ship actually cost, but as an experiment, it has shown fuel savings of 25% to 30% over conventional ships.
Part of the saving comes the use of four Flettner Rotors, 27m high x 4m in diameter, mounted on the "four corners" of the cargo deck.
Part of the economy of operation for the ship is also the result of its very fine underwater lines and its aerodynamic above water shape. It also utilizes sophisticated electronic controls to maximize engine efficiency.
From mid -2013 to February of this year, the ship was laid up for repairs after numerous technical glitches. The ship was also re-engined during that time, so its ultimate cost must be very high.
The Flettner rotors were also used in the 1920s and proved even then to be more efficient than conventional steam coal and diesel ships. High initial cost and the 1930s depression doomed the system until now.
It must remain to be seen whether this is just another experiment, or if it will be adopted over other innovative propulsion systems currently being developed.